115 results on '"Limor, R"'
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2. The acute ghrelin response to a psychological stress challenge does not predict the post-stress urge to eat
- Author
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Rouach, V., Bloch, M., Rosenberg, N., Gilad, S., Limor, R., Stern, N., and Greenman, Y.
- Published
- 2007
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3. Angiotensin 1-7 Prevents the Metabolic Syndrome, Hepatosteatosis and Adipose Tissue Inflammation (Adipositis) in the Fructose-Fed Rat.
- Author
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Marcus, Y, primary, Shechte, Y, additional, Kohen, F, additional, Limor, R, additional, Sasson, K, additional, Biton, I, additional, Fridkin, M, additional, and Stern, N, additional
- Published
- 2010
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4. Radioiodine Therapy for Graves' Disease Is Associated with Increased Rate of the Metabolic Syndrome.
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Izkhakov, E, primary, Osher, E, additional, Yaron, M, additional, Tordjman, K, additional, Greenman, Y, additional, Shenkerman, G, additional, Trostanetsky, Y, additional, Sack, J, additional, Azzam, I, additional, Ish-Shalom, M, additional, Limor, R, additional, and Stern, N, additional
- Published
- 2010
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5. Membranal effects of phytoestrogens and carboxy derivatives of phytoestrogens on human vascular and bone cells: New insights based on studies with carboxy-biochanin A
- Author
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Somjen, D., Kohen, F., Lieberherr, M., Gayer, B., Schejter, E., Katzburg, S., Limor, R., Sharon, O., Knoll, E., Posner, G.H., Kaye, A.M., and Stern, N.
- Published
- 2005
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- View/download PDF
6. Low-dose ACTH (1 μg) salivary test: a potential alternative to the classical blood test
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Marcus-Perlman, Y., Tordjman, K., Greenman, Y., Limor, R., Shenkerman, G., Osher, E., and Stern, N.
- Published
- 2006
7. Risk factor clustering in hypertensive patients: impact of the reports of NCEP-II and second joint task force on coronary prevention on JNC-VI guidelines
- Author
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Stern, N., Grosskopf, I., Shapira, I., Kisch, E., Isaacov, A., Limor, R., Baz, M., Leshem, Y., Flatau, E., Miller, A., and Greenman, Y.
- Published
- 2000
8. Ghrelin stimulation by hypothalamic–pituitary–adrenal axis activation depends on increasing cortisol levels
- Author
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Azzam, I, primary, Gilad, S, additional, Limor, R, additional, Stern, N, additional, and Greenman, Y, additional
- Published
- 2017
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- View/download PDF
9. GW9662, A PPAR γ-ANTAGONIST, INHIBITS TELMISARTAN- MEDIATED GENE MODULATION, AND ACTIVATED PPARα
- Author
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Younis, F., primary, Oron, Y., additional, Stern, N., additional, Limor, R., additional, and Rosenthal, T., additional
- Published
- 2011
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10. TELMISARTAN PREVENTS DEVELOPMENT OF HYPERTENSION AND AMELIORATES DIABETIC PROFILE IN COHEN ROSENTHAL DIABETIC HYPERTENSIVE (CRDH) RATS: PP.13.491
- Author
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Younis, F, primary, Oron, Y, additional, Limor, R, additional, Stern, N, additional, and Rosenthal, T, additional
- Published
- 2010
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- View/download PDF
11. Lipoxygenase-derived Metabolites Are Regulators of Peroxisome Proliferator-activated Receptor -2 Expression in Human Vascular Smooth Muscle Cells
- Author
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Limor, R., primary, Sharon, O., additional, Knoll, E., additional, Many, A., additional, Weisinger, G., additional, and Stern, N., additional
- Published
- 2008
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- View/download PDF
12. Low-dose ACTH (1 ug) salivary test: a potential alternative to the classical blood test
- Author
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Marcus-Perlman, Y., primary, Tordjman, K., additional, Greenman, Y., additional, Limor, R., additional, Shenkerman, G., additional, Osher, E., additional, and Stern, N., additional
- Published
- 2006
- Full Text
- View/download PDF
13. Mullerian Inhibiting Factor Levels Don’t Predict Ovarian Reserve Following Chemotherapy in Patients With Hodgkin’s Disease
- Author
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Azem, F., primary, Samara, N., additional, Limor, R., additional, Wagman, I., additional, Ben-Yosef, D., additional, and Amit, A., additional
- Published
- 2005
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14. Intrarenal and cardiac expression of endothelin-1, ETA and ETB receptors in Cohen-Rosenthal Diabetic Hypertensive rats
- Author
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HOFMAN, C, primary, LIMOR, R, additional, ROSENTHAL, T, additional, ZAID, A, additional, and STERN, N, additional
- Published
- 2005
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15. Angiotensin II increases the expression of lectin-like oxidized low-density lipoprotein receptor-1 in human vascular smooth muscle cells via a lipoxygenase-dependent pathway
- Author
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LIMOR, R, primary, KAPLAN, M, additional, SAWAMURA, T, additional, SHARON, O, additional, KEIDAR, S, additional, WEISINGER, G, additional, KNOLL, E, additional, NAIDICH, M, additional, and STERN, N, additional
- Published
- 2005
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16. A case of hypergonadotrophinaemia associated with very high isolated concentrations of immunologically and biologically active lutemizing hormone
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Eckstein, N., primary, Huhtaniemi, I., additional, Vagman, I., additional, Pakarinen, P., additional, Limor, R., additional, and Ayalon, D., additional
- Published
- 1996
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17. The effect of the hypoestrogenic state, induced by gonadotropin-releasing hormone agonist, on Doppler-derived parameters of aortic flow.
- Author
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Eckstein, N, primary, Pines, A, additional, Fisman, E Z, additional, Fisch, B, additional, Limor, R, additional, Vagman, I, additional, Barnan, R, additional, and Ayalon, D, additional
- Published
- 1993
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18. Calcium homeostasis, bone metabolism and safety aspects during long-term treatment with a GnRH agonist
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Eckstein, N., primary, Foldes, J., additional, Feinstein, Y., additional, Vagman, I., additional, Eshel, A., additional, Steinberg, R., additional, Statter, M., additional, Limor, R., additional, and Ayalon, D., additional
- Published
- 1992
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19. 25-hydroxyvitamin D3-1alpha-hydroxylase is expressed in human vascular smooth muscle cells and is upregulated by parathyroid hormone and estrogenic compounds.
- Author
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Somjen D, Weisman Y, Kohen F, Gayer B, Limor R, Sharon O, Jaccard N, Knoll E, Stern N, Somjen, Dalia, Weisman, Yosef, Kohen, Fortune, Gayer, Batya, Limor, Rona, Sharon, Orly, Jaccard, Niva, Knoll, Esther, and Stern, Naftali
- Published
- 2005
20. Thyrotropin, menopause, and hormone replacement.
- Author
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Pines A, Ironi A, Levo Y, Averbuch M, Limor R, and Ayalon D
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- 1993
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21. Another look at co-treatment with growth hormone and human menopausal gonadotrophins in poor ovarian responders.
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Levy, Tally, Limor, Rona, Villa, Yael, Eshel, Alex, Eckstein, Nachman, Vagman, Israel, Lidor, Arie, Ayalon, Daniel, Levy, T, Limor, R, Villa, Y, Eshel, A, Eckstein, N, Vagman, I, Lidor, A, and Ayalon, D
- Abstract
The objective of this study was to evaluate whether a combined human growth hormone (HGH) and human menopausal gonadotrophin (HMG) treatment can improve ovulation induction in poor ovarian responders. Ten patients aged 28–43 years and requiring > 25 ampoules of HMG for ovulation were admitted to the study. Pituitary growth hormone reserve was evaluated by clonidine stimulation and insulin tolerance tests before commencement of treatment. The patients underwent one treatment cycle with D-tryptophan-6-luteinizing hormone-releasing hormone (-Trp-LHRH) and HMG and another cycle with -Trp-LHRH, HMG and HGH. Serum HGH, insulin-like growth factor (IGF)-I and oestradiol were measured throughout the two treatment cycles and follicular maturation was assessed by ultrasonographic studies. All patients tested showed no elevation of their serum HGH concentration during a clonidine test, but showed an adequate response during insulin tolerance tests. No significant difference was found in the number of HMG ampoules, duration of treatment, number of leading follicles, and serum oestradiol concentration between the two treatment cycles. Co-treatment with HGH and HMG did not improve ovarian performance in poor ovarian responders. No correlation was found between the results of HGH pituitary function tests and the ovarian response to gonadotrophins. [ABSTRACT FROM PUBLISHER]
- Published
- 1993
22. Induction of ovulation with D-Trp6-LHRH combined with purified FSH in patients with polycystic ovarian disease.
- Author
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Ayalon, D., Ben-David, M., Wohl, R., Jaffe, R., Vagman, I., Eckstein, N., Limor, R., Comaru-Schally, A. M., and Schally, A. V.
- Published
- 1988
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23. Paradoxical hypersecretion of growth hormone in patients with endometrial atypical hyperplasia and carcinoma. Effect of hysterectomy.
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Ayalon, Daniel, Peyser, Reuben, Limor, Rodica, Lessing, Joseph B., Ravid, Roma, Ayalon, D, Peyser, M R, Limor, R, Lessing, J B, and Ravid, R
- Published
- 1982
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24. Induction of ovulation with D-Trp6-LHRH combined with purified FSH in patients with polycystic ovarian disease
- Author
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Ayalon, D., Ben-David, M., Wohl, R., Jaffe, R., Vagman, I., Eckstein, N., Limor, R., Comaru-Schally, A. M., and Schally, A. V.
- Abstract
Seventeen patients with polycystic ovarian disease (PCOD) and evidence of mild or severe ovarian hyperstimulation syndrome (OHSS) during therapy with CC/hCG, FSH/hCG or hMG/hCG were treated with D-Trp6-LHRH until medical gonadectomy was attained. Under the suppressive therapy with the GnRH agonist (GnRHa) ovulation was induced with FSH/hCG. In 15 out of 17 patients, ovulatory cycles were obtained with this new modality of treatment. Seven patients conceived (3 viable pregnancies and 4 early abortions) after the 1st treatment cycle. Fourteen of the 17 patients demonstrated symptoms of mild OHSS which did not require hospitalization. Only 1 patient developed severe OHSS after the combined treatment.Our results suggest that therapy with GnRHa, especially in its delayed release formulation, is effective for the prevention of severe ovarian hyperstimulation in PCOD patients undergoing treatment with menotropins for the induction of ovulation.
- Published
- 1988
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25. Gonadotropin-releasing hormone activates a rapid Ca2+-independent phosphodiester hydrolysis of polyphosphoinositides in pituitary gonadotrophs.
- Author
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Naor, Z, Azrad, A, Limor, R, Zakut, H, and Lotan, M
- Abstract
Addition of gonadotropin releasing hormone (GnRH) to pituitary cells prelabeled with [32P]Pi or with myo-[2-3H]inositol, resulted in a rapid decrease in the level of [32P]phosphatidylinositol 4,5-bisphosphate (approximately 10 s), and in [32P]phosphatidylinositol 4-phosphate (approximately 1 min), followed by increased labeling of [32P]phosphatidylinositol and [32P]phosphatidic acid (1 min). GnRH stimulated the appearance of [3H]myo-inositol 1,4,5-trisphosphate (10 s), [3H]myo-inositol 1,4-bisphosphate (15 s), and [3H]myo-inositol 1-phosphate (1 min) in the presence of Li+ (10 mM). Li+ alone stimulated the accumulation of [3H]myo-inositol 1-phosphate and [3H]myo-inositol 1,4-bisphosphate but not [3H]myo-inositol 1,4,5-trisphosphate, but had no effect on luteinizing hormone release. The effect of GnRH on inositol phosphates (Ins-P) production was dose-related (ED50 = 1-5 nM), and was blocked by a potent antagonist [D-pGlu,pClPhe,D-Trp]GnRH. Elevation of cytosolic free Ca2+ levels ([Ca2+]i), by ionomycin and A23187 from intracellular or extracellular Ca2+ pools, respectively, had no significant effect on [3H]Ins-P production. GnRH-induced [3H]Ins-P production was not dependent on extracellular Ca2+ and was noticed also after extracellular or intracellular Ca2+ mobilization by A23187 or ionomycin, respectively. The effect of GnRH on [3H]Ins-P accumulation was not affected by prior treatment of the cells with the tumor promoter phorbol ester 12-O-tetradecanoylphorbol-13-acetate or with islet-activating protein pertussis toxin. These results indicate that GnRH stimulates a rapid phosphodiester hydrolysis of polyphosphoinositides. The stimulatory effect is not mediated via an islet-activating protein-substrate, is not dependent on elevation of [Ca2+]i, neither is it negatively regulated by 12-O-tetradecanoylphorbol-13-acetate which activates Ca2+/phospholipid-dependent protein C kinase. The results are consistent with the hypothesis that GnRH-induced phosphoinositide turnover is responsible for Ca2+ mobilization followed by gonadotropin release.
- Published
- 1986
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26. Contaminant eluted from solid-phase plasmid affinity-purification protocol columns is not found using liquid-phase methods and can be prevented
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Limor, R., Gilad, S., Kutikof, E., Jaffe, A., Tendler, Y., Gazit, V., Stern, N., and Weisinger, G.
- Published
- 1999
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27. Induction of exocytosis in permeabilized pituitary cells by alpha- and beta-type protein kinase C.
- Author
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Naor, Z, Dan-Cohen, H, Hermon, J, and Limor, R
- Abstract
Protein kinase C is now recognized to comprise a family of closely related subspecies (PKCs). When cultured rat pituitary cells were permeabilized by digitonin for 5 min in the absence of Ca2+, endogenous PKC activity was decreased by 72%. PKC depletion was also achieved by prior treatment (24 hr) with high concentrations of phorbol 12-myristate 13-acetate (PMA). When purified activated brain PKCs were added for 30 min to PMA-pretreated, digitonin-permeabilized cells, only alpha- and beta- but not gamma-type PKC stimulated luteinizing hormone release. Since PKC was implicated as a mediator of gonadotropin secretion, gonadotropin-releasing hormone might utilize alpha- and beta-type PKCs for stimulation of gonadotropin secretion; alpha- and beta-type PKCs might participate also in other exocytotic responses in diverse biological systems in which PKC was implicated.
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- 1989
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28. Paradoxe Hypersekretion des Wachstumshormons bei Patientinnen mit atypischer Hyperplasie des Endometriums und Endometriumkarzinom; die Auswirkung der Uterusexstirpation
- Author
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Ayalon, Daniel, primary, Peyser, Reuben, additional, Rodica Limor, R., additional, Lessing, Joseph B., additional, and Ravid, Roma, additional
- Published
- 1982
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29. A NOVEL PLATELET TYPE 12 LIPOXYGENASE mRNA AND PROTEIN IS EXPRESSED IN HUMAN VASCULAR SMOOTH MUSCLE CELLS.
- Author
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Limor, R., Weisinger, G., Gilad, S., Knoll, E., Sharon, O., Jaffe, A., Lifschitz-Mercar, B., Berger, E., Kohen, F., and Stern, N.
- Published
- 1999
30. Alcohol Drinks Induce Acute Lowering in Circulating l-Arginine in Obese and Type 2 Diabetic Subjects.
- Author
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Buch A, Ganz T, Wainstein J, Gilad S, Limor R, Shefer G, Boaz M, and Stern N
- Subjects
- Humans, Obesity blood, Overweight, Weight Loss, Alcohol Drinking, Arginine blood, Diabetes Mellitus, Type 2
- Abstract
Since low serum l -arginine (Arg) and high asymmetric dimethylarginine (ADMA) can predict microvascular complications in type 2 diabetes mellitus (T2DM), we tested whether Arg and ADMA are affected by diet and physical activity in overweight/obese and T2DM subjects. We tested the effects on serum Arg and ADMA of single loads of dextrose, protein, fat, or alcohol (∼300 calories each); one episode of physical exercise; and 12 weeks of standard lifestyle modification (dietary and physical activity counseling). Alcohol drink was followed by ∼30% lowering in Arg. Arg and ADMA increased after a protein load but remained stable after glucose or fat load or 30 min of treadmill walk. Following 12 weeks of lifestyle modification, ADMA declined only in subjects achieving weight loss >5%. In conclusion, alcohol is a previously unrecognized acute suppressor of serum Arg. Lifestyle modification lowers ADMA in subjects who achieve weight loss >5%. Clinical Trial Registration Number: NCT04406402.
- Published
- 2022
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31. Mechanism of Hyponatremia in Community-Acquired Pneumonia: Does B-type Natriuretic Peptide Play a Causative Role?
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Hausman-Kedem M, Reif S, Danino D, Limor R, Grinspan ZM, Yerushalmi-Feler A, Ben-Tov A, and Birger A
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- Child, Child, Preschool, Community-Acquired Infections blood, Community-Acquired Infections complications, Community-Acquired Infections urine, Electrolytes blood, Electrolytes urine, Female, Humans, Hyponatremia blood, Hyponatremia urine, Infant, Male, Pneumonia blood, Pneumonia urine, Hyponatremia etiology, Natriuretic Peptide, Brain blood, Peptide Fragments blood, Pneumonia complications
- Abstract
Objective: Hyponatremia is a well-known sequela of community-acquired pneumonia (CAP). B-type natriuretic peptide (BNP) has a natriuretic effect and was found to be elevated in patients with CAP. We investigated whether BNP has a role in the pathophysiology of hyponatremia in pediatric CAP., Methods: Serum and urine electrolytes and osmolality, as well as NT-pro-BNP (N-BNP), were obtained in 49 hospitalized pediatric patients with CAP (29 with hyponatremia, 20 with normal sodium levels., Results: Urine sodium levels were lower in the hyponatremic group compared with the normonatremic group (24.3 meq/L vs 66.7 meq/L, P = 0.006). No difference in N-BNP levels was found between groups (median, 103.8 vs 100.1; P = 0.06; interquartile range, 63.7-263.3 pg/mL vs 47.4-146.4 pg/mL). N-BNP was not associated with serum or urinary sodium levels., Conclusions: These results indicate that BNP is unlikely to play a causative role in the mechanism of hyponatremia in CAP.
- Published
- 2018
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32. A Single Radioactive Iodine Treatment Has a Deleterious Effect on Ovarian Reserve in Women with Thyroid Cancer: Results of a Prospective Pilot Study.
- Author
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Yaish I, Azem F, Gutfeld O, Silman Z, Serebro M, Sharon O, Shefer G, Limor R, Stern N, and Tordjman KM
- Subjects
- Adult, Anti-Mullerian Hormone blood, Female, Humans, Iodine Radioisotopes administration & dosage, Middle Aged, Pilot Projects, Prospective Studies, Thyroid Neoplasms blood, Young Adult, Iodine Radioisotopes therapeutic use, Ovarian Reserve radiation effects, Thyroid Neoplasms radiotherapy
- Abstract
Background: Women of reproductive age with differentiated thyroid cancer (DTC) often need radioactive iodine (RAI) treatment after surgery. In contrast to the well-documented effect of RAI on testicular function, the potential negative effects of this treatment on ovarian reserve have been largely dismissed. The objective of this pilot study was to examine the possibility that RAI treatment is deleterious to the ovarian reserve by prospectively measuring the concentration of anti-Müllerian hormone (AMH) after RAI treatment., Methods: Thirty premenopausal women (M
age = 34 years; range 20-45 years) with a new diagnosis of DTC scheduled to undergo RAI ablation were recruited for this study. All of them had TNM stage 1 disease (T1-3, N0, or N1, M0), and were scheduled to receive RAI activities ranging from 30 to 150 mCi. AMH was measured at baseline and at 3, 6, 9, and 12 months after the administration of RAI., Results: Of the 30 women, only 24 returned after the baseline assessment. RAI treatment resulted in a significant decrease in AMH concentrations at three months, from 3.25 ± 2.75 to 1.9 ± 1.74 ng/mL (p < 0.0001). Only partial recovery was subsequently documented. Eighty-two percent of subjects had final values below baseline levels, such that at one year, serum AMH was still 32% lower than prior to treatment (2.36 ± 1.88 ng/mL; p < 0.005). The only two continuous variables that correlated with the extent of AMH reduction at three months were the woman's age (r = 0.51; p = 0.02) and the age at menarche (r = 0.48; p = 0.03). Importantly, the RAI dose was not associated with the extent of AMH reduction and neither were smoking or the use of birth control pills. Older subjects (≥35 years) were significantly more likely to experience a marked AMH reduction at three months (63.7 ± 18.5% vs. 33.1 ± 29.2%; p = 0.01). The only predictor of recovery after one year was the extent of AMH decrease at three months: the lower the decline, the higher the chances for recovery., Conclusions: RAI in DTC has a rapid and profound effect on ovarian reserve, with only a partial recovery potential. In an era of declining human fertility, it is of relevance to recognize the potentially adverse effect of RAI in women of reproductive age. AMH measurement may be useful as a tool in this decision-making process.- Published
- 2018
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33. Serum asymmetric dimethylarginine and arginine levels predict microvascular and macrovascular complications in type 2 diabetes mellitus.
- Author
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Ganz T, Wainstein J, Gilad S, Limor R, Boaz M, and Stern N
- Subjects
- Adolescent, Adult, Aged, Cardiovascular Diseases blood, Cardiovascular Diseases etiology, Case-Control Studies, Cross-Sectional Studies, Diabetes Complications blood, Diabetes Complications etiology, Female, Follow-Up Studies, Humans, Male, Middle Aged, Oxidative Stress, Prognosis, Prospective Studies, Risk Factors, Young Adult, Arginine analogs & derivatives, Arginine blood, Biomarkers blood, Cardiovascular Diseases diagnosis, Diabetes Complications diagnosis, Diabetes Mellitus, Type 2 complications
- Abstract
Background: Increased oxidative stress in diabetes increases nitric oxide (NO) oxidation and low l-arginine (Arg) could further reduce NO and impair vascular function, thereby accelerating, in the long run, vascular complications. We therefore measured Arg and asymmetric dimethylarginine (ADMA) levels in patients with type 2 diabetes mellitus (T2DM) and healthy controls. Additionally, we observed the diabetic individuals over time to see if Arg and asymmetric dimethylarginine predicted T2DM complications., Methods: We examined baseline serum Arg and ADMA levels in a cohort of 105 participants with type 2 diabetes and compared them with an age- and weight-matched nondiabetic group of 137 individuals who served as a reference population. Additionally, we assessed whether Arg and/or ADMA predicted macrovascular and microvascular complications over 6 years of follow-up., Results: Serum Arg was lower in individuals with T2DM than in controls (64 ± 28 vs 75 ± 31 μmol/L; P = .009) and inversely related to hemoglobin A1c (r = -0.2; P = .002). Over follow-up, we observed that participants with T2DM in the lowest quartile of Arg had increased risk for the subsequent evolution of nephropathy, peripheral neuropathy, and composite microvascular complications (odds ratio [OR] = 5.5; 95% confidence interval [CI] -1.9 to 16; P = .002). The highest ADMA quartile was associated with increased risk for both microvascular (OR = 4.5; 95% CI -1.4 to 14.1; P = .009) and 6.5-year incident macrovascular complications (OR = 8.3; 95% CI 1.9-35.5; P = .004)., Conclusion: l-Arginine levels are lower in individuals with T2DM than in matched controls. Both low Arg and high ADMA, independent of each other and adjusted for classical risk factors, predict the incidence of microvascular complications., (Copyright © 2016 John Wiley & Sons, Ltd.)
- Published
- 2017
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34. GENDER DETERMINES SERUM FREE CORTISOL: HIGHER LEVELS IN MEN.
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Sofer Y, Osher E, Limor R, Shefer G, Marcus Y, Shapira I, Tordjman K, Greenman Y, Berliner S, and Stern N
- Subjects
- Adolescent, Adrenocorticotropic Hormone administration & dosage, Adult, Aged, Aged, 80 and over, Female, Healthy Volunteers, Humans, Male, Middle Aged, Young Adult, Adrenocorticotropic Hormone pharmacology, Hydrocortisone blood, Sex Characteristics
- Abstract
Objective: Because only the free fraction of serum cortisol can readily access glucocorticoid receptors, we investigated whether or not a gender-related difference in serum free cortisol (FC) exists in the basal and adrenocorticotropic hormone (ACTH)-stimulated state., Methods: Serum total cortisol (TC) and FC were measured in 323 subjects (175 men; 148 women). Additionally, the low-dose 1-μg ACTH test was performed in 56 subjects (30 women, 26 men). Subjects were healthy volunteers, recruited in a preventive medicine screening program and an outpatient clinic., Results: Overall, basal serum TC and FC level were ~18 and ~33%, respectively, higher in men than in women (TC, 14.5 ± 0.33 μg/dL vs. 12.3 ± 0.33 μg/dL; P<.0001; FC, 0.68 ± 0.02 μg/dL vs. 0.51 ± 0.02 μg/dL; P<.0001). The higher FC in men relative to women was apparent across a wide age range (17 to 86 years) and persisted after adjustment for age and body mass index. The FC fraction (%FC, out of TC) was concordantly higher in men (5.4 ± 0.09% vs. 4.8 ± 0.3%; P = .046). FC was not related to the estimated menopausal status (women age below and above 47, 50, or 53 years). ACTH-stimulated FC levels were significantly higher in men compared to women, as reflected by the area under the response curve (49.4 ± 3.4 μg × min vs. 39.6 ± 2.2 μg × min; P = .0014)., Conclusion: Gender is an unrecognized determinant of serum FC in humans. The possibility of lifelong exposure to the higher bioactive fraction of cortisol under basal conditions or daily stress involving ACTH stimulation should be further investigated in the context of gender-related phenotypic features such as "android" (visceral) fat deposition and longevity., Abbreviations: ACTH = adrenocorticotropic hormone BMI = body mass index CBG = cortisol-binding globulin FC = free cortisol HPA = hypothalamic-pituitary-adrenal TC = total cortisol.
- Published
- 2016
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35. Estradiol-17β increases 12- and 15-lipoxygenase (type2) expression and activity and reactive oxygen species in human umbilical vascular smooth muscle cells.
- Author
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Somjen D, Kohen F, Limor R, Sharon O, Knoll E, Many A, and Stern N
- Subjects
- 12-Hydroxy-5,8,10,14-eicosatetraenoic Acid metabolism, Arachidonate 12-Lipoxygenase metabolism, Arachidonate 15-Lipoxygenase metabolism, Estrogen Receptor alpha genetics, Estrogen Receptor alpha metabolism, Estrogen Receptor beta genetics, Estrogen Receptor beta metabolism, Flavanones pharmacology, Gene Expression Regulation, Humans, Hydroxyeicosatetraenoic Acids metabolism, Muscle, Smooth, Vascular cytology, Muscle, Smooth, Vascular drug effects, Muscle, Smooth, Vascular metabolism, Myocytes, Smooth Muscle cytology, Myocytes, Smooth Muscle metabolism, NADPH Oxidases genetics, NADPH Oxidases metabolism, Nitriles pharmacology, Phenols pharmacology, Piperidines pharmacology, Primary Cell Culture, Propionates pharmacology, Pyrazoles pharmacology, Pyrimidines pharmacology, RNA, Messenger genetics, RNA, Messenger metabolism, Raloxifene Hydrochloride pharmacology, Reactive Oxygen Species agonists, Umbilical Veins cytology, Umbilical Veins drug effects, Umbilical Veins metabolism, Arachidonate 12-Lipoxygenase genetics, Arachidonate 15-Lipoxygenase genetics, Estradiol pharmacology, Myocytes, Smooth Muscle drug effects, Reactive Oxygen Species metabolism
- Abstract
The net vascular effect of estrogens on the vasculature is still under debate. Here we tested the effects of estradiol- 17β (E2) as well as estrogen-receptor subtype specific and non-specific agonists and antagonists on the expression and eicosanoid production of lipoxygenase (LO) enzymes expressed in culture human umbilical vascular smooth muscle cells (VSMC), the platelet type 12LO and 15LO type 2. E2 increased 12 and 15LO mRNA expression by 2-3 folds and elicited an acute 50% increase 12 and 15 hydroxyeicosatetraenoic acid (HETE) production. Neither estrogen receptor ERα nor ERβ-specific agonists were able to reproduce the induction of LO expression, but E2-induced expression was effectively blocked by ER non-specific and receptor subtype specific antagonists. Because 12 and 15HETE can increase reactive oxygen species in other cell types, we tested the possibility that E2 could raise ROS through LO. Indeed, E2 as well as the LO products 12 and 15HETE increased reactive oxygen species (ROS) in VSMC. E2-dependent and HETE-induced ROS could be blocked by NAD (P) H-oxidase inhibitors and by the ER general antagonist ICI. E2-induced ROS was partially (∼50%) blocked by the LO inhibitor baicalein, but the LO blocker had no effect on 12 or 15HETE- induced ROS formation, thus suggesting that part of E2-dependent ROS generation resulted from E2-induced 12 and 15HETE. Collectively these findings unveil an unrecognized effect of E2 in human VSMC, to induce 12 and 15LO type 2 expression and activity and suggest that E2-dependent ROS formation in VSMC may be partially mediated by the induction of 12 and 15HETE., (Copyright © 2016 Elsevier Ltd. All rights reserved.)
- Published
- 2016
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36. Angiotensin 1-7 Is a Negative Modulator of Aldosterone Secretion In Vitro and In Vivo.
- Author
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Shefer G, Marcus Y, Knoll E, Dolkart O, Foichtwanger S, Nevo N, Limor R, and Stern N
- Subjects
- Animals, Antihypertensive Agents metabolism, Antihypertensive Agents pharmacology, Fluorescent Antibody Technique methods, Humans, Proto-Oncogene Mas, Rats, Renin-Angiotensin System physiology, Aldosterone blood, Aldosterone metabolism, Angiotensin I metabolism, Angiotensin I pharmacology, Hypertension metabolism, Peptide Fragments metabolism, Peptide Fragments pharmacology, Zona Glomerulosa metabolism
- Abstract
Angiotensin (1-7) [Ang 1-7] is a 7 amino acid peptide generated predominantly from Ang II by the action of Ang-converting enzyme 2. We previously showed that Ang 1-7 reduced plasma aldosterone and plasma renin activity in high fructose-fed rats, and that the reduction in circulating aldosterone seemed to accord a parallel reduction in plasma renin activity. Here, we tested the possibility that Ang 1-7 affects aldosterone secretion acting directly in glomerulosa cells. First, as detected by immunofluorescence, the receptor for Ang 1-7, Mas1 is localized predominantly at the rat adrenal subcapsular region. Second, in isolated rat glomerulosa cells incubates, Ang 1-7 attenuated the aldosterone response to Ang II, with the strongest effect seen on Ang II (10(-9) M) (control 22±2.5 pg/10(5) cells; Ang II [10(-9) M] 189±11 pg/10(5) cells; Ang II [10(-9) M]+Ang 1-7 [10(-6) M] 33±3.6 pg/10(5) cells; P<0.001) and the largest effect on adrenocorticotropic hormone (10(-8) M) (control 30±3.4 pg/10(5) cells; ACTH [10(-8) M] 409±32.5 pg/10(5) cells; ACTH [10(-8) M]+Ang 1-7 [10(-6) M] 280±12.5 pg/10(5) cells; P<0.001). In contrast, Ang 1-7 did not affect the aldosterone response to potassium (K(+)). In rats subjected to a low-salt diet for 7 days, continuous infusion of Ang 1-7 (576 μg/kg per day) resulted in a lesser rise in aldosterone (salt deplete+Ang 1-7, 16.4±4.8 ng/dL) compared with rats receiving vehicle (salt deplete+vehicle, 27.6±5.3 ng/dL; P<0.01) but did not modify plasma renin activity. Taken together, these results indicate that Ang 1-7 can act as a negative modulator of aldosterone secretion in vitro and in vivo., (© 2016 American Heart Association, Inc.)
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- 2016
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37. Vitamin D receptor expression is linked to potential markers of human thyroid papillary carcinoma.
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Izkhakov E, Somjen D, Sharon O, Knoll E, Aizic A, Fliss DM, Limor R, and Stern N
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- Adolescent, Adult, Aged, Biomarkers, Tumor genetics, Extracellular Matrix Proteins genetics, Extracellular Matrix Proteins metabolism, Female, Gene Expression, Humans, Male, Membrane Proteins genetics, Membrane Proteins metabolism, Middle Aged, Receptors, Calcitriol genetics, Serine Endopeptidases genetics, Serine Endopeptidases metabolism, Thyroid Gland metabolism, Thyroid Gland pathology, Young Adult, Biomarkers, Tumor metabolism, Carcinoma, Papillary metabolism, Receptors, Calcitriol metabolism, Thyroid Neoplasms metabolism
- Abstract
Genes regulated cell-cell and cell-matrix adhesion and degradation of the extracellular matrix (ECM) have been screened as potential markers of malignant thyroid nodules. The mRNA expression levels of two of them, the ECM protein-1 (ECM1) and the type II transmembrane serine protease-4 (TMPRSS4), were shown to be an independent predictor of an existing thyroid carcinoma. The vitamin D receptor (VDR) is expressed in epithelial cells of the normal thyroid gland, as well as in malignant dividing cells, which respond to the active metabolite of vitamin D by decreased proliferative activity in vitro. We evaluated the relationship between mRNA gene expressions of TMPRSS4, ECM1 and VDR in 21 papillary thyroid carcinoma samples and compared it to 21 normal thyroid tissues from the same patients. Gene expression was considered as up- or down-regulated if it varied by more or less than 2-fold in the cancer tissue relative to the normal thyroid tissue (Ca/N) from the same patient. We found an overall significant adjusted correlation between the mRNA expression ratio (ExR) of VDR and that of ECM1 in Ca/N thyroid tissue (R=0.648, P<0.001). There was a high ExR of VDR between Ca/N thyroid tissue from the same patient (3.06±2.9), which also exhibited a high Ca/N ExR of ECM1 and/or of TMPRSS4 (>2, P=0.05).The finding that increased VDR expression in human thyroid cancer cells is often linked to increased ECM1 and/or TPMRSS4 expression warrants further investigation into the potential role of vitamin D analogs in thyroid carcinoma., (Copyright © 2016 Elsevier Ltd. All rights reserved.)
- Published
- 2016
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38. Establishing Normal Ranges of Basal and ACTH-Stimulated Serum Free Cortisol in Children.
- Author
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Eyal O, Limor R, Oren A, Schachter-Davidov A, Stern N, and Weintrob N
- Subjects
- Adolescent, Child, Child, Preschool, Female, Humans, Infant, Male, Adrenocorticotropic Hormone, Hydrocortisone blood
- Abstract
Background: Normative data have been established for stimulated serum total cortisol in children but not for serum free cortisol., Methods: Children who were referred for ACTH testing to rule out adrenal insufficiency were enrolled. Only children with normal response and normal androgen levels were included. Total cortisol was determined by a chemiluminescence method, and free cortisol was measured by the same method following equilibrium dialysis., Results: The study group consisted of 85 subjects (28 male; 57 female) with a median age of 8.5 years (range 0.6-17.7). The mean basal and peak total cortisol levels were 11.5 ± 5.7 and 32.9 ± 6.2 μg/dl, respectively. The mean basal and peak free cortisol levels were 0.4 ± 0.3 and 1.8 ± 0.6 μg/dl, respectively. There was a negative correlation between peak total cortisol and age but not between peak free cortisol and age. The 3rd and 97th percentile values for peak free cortisol were 0.94 μg/dl (26 nmol/l) and 2.97 μg/dl (82 nmol/l), respectively., Conclusions: Measurement of free cortisol has the advantage of being independent of cortisol-binding globulin levels. This study provides reference ranges for stimulated free cortisol in children, with a cutoff value of 0.9 μg/dl (25 nmol/l) as a normal response to a standard ACTH test., (© 2016 S. Karger AG, Basel.)
- Published
- 2016
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39. Multidisciplinary Treatment of the Metabolic Syndrome Lowers Blood Pressure Variability Independent of Blood Pressure Control.
- Author
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Marcus Y, Segev E, Shefer G, Sack J, Tal B, Yaron M, Carmeli E, Shefer L, Margaliot M, Limor R, Gilad S, Sofer Y, and Stern N
- Subjects
- Carotid Intima-Media Thickness, Diet, Mediterranean, Exercise Therapy, Female, Humans, Hypertension diet therapy, Hypertension physiopathology, Hypertension therapy, Male, Metabolic Syndrome diet therapy, Middle Aged, Pulse Wave Analysis methods, Blood Pressure physiology, Blood Pressure Monitoring, Ambulatory methods, Metabolic Syndrome physiopathology, Metabolic Syndrome therapy
- Abstract
Blood pressure (BP) variability (BPV) contributes to target organ damage independent of BP. The authors examined the effect of a 1-year multidisciplinary intervention on BPV in patients with the metabolic syndrome (MetS) as defined by criteria from the Third Report of the Adult Treatment Panel. Forty-four nondiabetic patients underwent clinical and biochemical profiling, 24-hour ambulatory BP monitoring (ABPM), body composition, carotid intima-media thickness, and carotid-femoral pulse wave velocity (PWV). The intervention targeted all MetS components. BPV was assessed by the standard deviation of daytime systolic BP derived from ABPM. Patients with low and high BPV (lower or higher than the median daytime standard deviation of 11.6 mm Hg) did not differ in regards to systolic and diastolic BP, age, fasting glucose, glycated hemoglobin, and body mass index, but the high-variability group had higher values of low-density lipoprotein and leg fat. The 1-year intervention resulted in weight reduction but not BP-lowering. BPV declined in the high-variability group in association with lowering of PWV, C-reactive protein, glycated hemoglobin, alanine aminotransferase, asymmetric dimethylarginine, and increased high-density lipoprotein cholesterol. A multidisciplinary intervention independent of BP-lowering normalized BPV, lowered PWV, and enhanced metabolic control., (© 2015 Wiley Periodicals, Inc.)
- Published
- 2016
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40. Angiotensin 1-7 as means to prevent the metabolic syndrome: lessons from the fructose-fed rat model.
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Marcus Y, Shefer G, Sasson K, Kohen F, Limor R, Pappo O, Nevo N, Biton I, Bach M, Berkutzki T, Fridkin M, Benayahu D, Shechter Y, and Stern N
- Subjects
- Adipose Tissue drug effects, Adipose Tissue metabolism, Animals, Disease Models, Animal, Drug Administration Schedule, Epididymis metabolism, Extracellular Signal-Regulated MAP Kinases genetics, Extracellular Signal-Regulated MAP Kinases metabolism, Gene Expression Regulation drug effects, Male, Muscle, Skeletal, Oxidative Stress, Phosphorylation, Proto-Oncogene Mas, Proto-Oncogene Proteins metabolism, Rats, Rats, Wistar, Reactive Oxygen Species, Receptors, G-Protein-Coupled metabolism, Transcription Factor RelA genetics, Transcription Factor RelA metabolism, Angiotensin I administration & dosage, Cardiovascular Agents administration & dosage, Dietary Carbohydrates administration & dosage, Fructose administration & dosage, Metabolic Syndrome prevention & control, Peptide Fragments administration & dosage
- Abstract
We studied the effects of chronic angiotensin 1-7 (Ang 1-7) treatment in an experimental model of the metabolic syndrome, i.e., rats given high-fructose/low-magnesium diet (HFrD). Rats were fed on HFrD for 24 weeks with and without Ang 1-7 (576 µg/kg/day, s.c., Alzet pumps). After 6 months, Ang 1-7-treated animals had lower body weight (-9.5%), total fat mass (detected by magnetic resonance imaging), and serum triglycerides (-51%), improved glucose tolerance, and better insulin sensitivity. Similar metabolic effects were also evident, albeit in the absence of weight loss, in rats first exposed to HFrD for 5 months and then subjected to short-term (4 weeks) treatment with Ang 1-7. Six months of Ang 1-7 treatment were associated with lower plasma renin activity (-40%) and serum aldosterone (-48%), less hepatosteatatitis, and a reduction in epididymal adipocyte volume. The marked attenuation of macrophage infiltration in white adipose tissue (WAT) was associated with reduced levels of the pP65 protein in the epididymal fat tissue, suggesting less activation of the nuclear factor-κB (NFκB) pathway in Ang 1-7-treated rats. WAT from Ang 1-7-treated rats showed reduced NADPH-stimulated superoxide production. In single muscle fibers (myofibers) harvested and grown ex vivo for 10 days, myofibers from HFrD rats gave rise to 20% less myogenic cells than the Ang 1-7-treated rats. Fully developed adipocytes were present in most HFrD myofiber cultures but entirely absent in cultures from Ang 1-7-treated rats. In summary, Ang 1-7 had an ameliorating effect on insulin resistance, hypertriglyceridemia, fatty liver, obesity, adipositis, and myogenic and adipogenic differentiation in muscle tissue in the HFrD rats.
- Published
- 2013
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41. Prophylactic treatment with telmisartan induces tissue-specific gene modulation favoring normal glucose homeostasis in Cohen-Rosenthal diabetic hypertensive rats.
- Author
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Younis F, Oron Y, Limor R, Stern N, and Rosenthal T
- Subjects
- Angiotensin II Type 1 Receptor Blockers therapeutic use, Animals, Antihypertensive Agents therapeutic use, Blood Glucose metabolism, Blood Glucose physiology, Chemoprevention methods, Diabetes Mellitus, Experimental complications, Diabetes Mellitus, Experimental genetics, Gene Expression Regulation drug effects, Homeostasis drug effects, Homeostasis genetics, Hypertension complications, Hypertension genetics, Male, Organ Specificity drug effects, Organ Specificity genetics, Rats, Rats, Inbred Strains, Telmisartan, Up-Regulation drug effects, Benzimidazoles therapeutic use, Benzoates therapeutic use, Blood Glucose drug effects, Blood Glucose genetics, Diabetes Mellitus, Experimental drug therapy, Hypertension drug therapy
- Abstract
The objectives were to assess the potential of long-term prophylactic administration of telmisartan, an angiotensin II receptor antagonist and a partial peroxisome proliferator activator receptor (PPAR)γ agonist, in preventing the development of hypertension and hyperglycemia and to demonstrate the alteration in gene expression associated with the development of hyperglycemia and insulin resistance in Cohen-Rosenthal diabetic hypertensive rat, a unique model of hypertension and type 2 diabetes mellitus comorbidity. Cohen-Rosenthal diabetic hypertensive rats were continuously treated with telmisartan (3 mg/[kg d]) starting at age 6 to 8 weeks before developing hypertension or diabetes. Weight changes, blood pressure, blood insulin, adiponectin, glucose tolerance, and insulin sensitivity were monitored. Fat, liver, and muscle messenger RNAs were examined for the expression of genes potentially involved in the onset of insulin resistance. In addition to the expected antihypertensive effect of prophylactic telmisartan, diabetes was blunted, evidenced at the end of the study by a significantly lower glucose level. This was accompanied by improved glucose tolerance, increased sensitivity to insulin, reduction in fasting insulin levels and homeostasis model assessment index, as well as an increase in serum adiponectin. Telmisartan also prevented the increase in serum triglycerides and the associated appearance of lipid droplets in the liver. Diabetes induced tissue-specific changes in messenger RNAs expression of the following selected genes, which were restored by telmisartan treatment: PPARγ, PPARδ, PPARγ coactivator 1α, adiponectin, adiponectin receptor 1, adiponectin receptor 2, phosphotyrosine binding domain and a pleckstrin homology domain-containing adaptor protein, adenosine monophosphate kinase, and glucose translocator 4. Telmisartan blunted the development of hypertension, insulin resistance, and diabetes in prediabetic Cohen-Rosenthal diabetic hypertensive rats through pleiotropic activity, involving specific gene regulation of target organs., (Copyright © 2012 Elsevier Inc. All rights reserved.)
- Published
- 2012
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42. Serum free cortisol as an ancillary tool in the interpretation of the low-dose 1-μg ACTH test.
- Author
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Limor R, Tordjman K, Marcus Y, Greenman Y, Osher E, Sofer Y, and Stern N
- Subjects
- Dose-Response Relationship, Drug, Endocrine System Diseases physiopathology, Humans, Hydrocortisone analysis, Hypothalamo-Hypophyseal System physiopathology, Pituitary-Adrenal System physiopathology, Sensitivity and Specificity, Adrenocorticotropic Hormone administration & dosage, Endocrine System Diseases diagnosis, Hydrocortisone blood, Salivary Glands metabolism
- Abstract
Objective: Serum free cortisol, rather than serum total cortisol (TC), determines glucocorticoid activity in vivo, but how the considerable inter-subject variation in ambient serum free cortisol affects the outcome of dynamic hypothalamic-pituitary-adrenal (HPA) assessment in noncritically ill subjects is unknown., Design, Patients and Measurements: We performed the low-dose 1-μg ACTH test in 75 subjects referred for HPA evaluation. Serum TC was determined by a chemiluminescence method, and serum free cortisol was measured by the same method following equilibrium dialysis. In a subset of these patients, salivary cortisol was also measured., Results: Mean fraction of free cortisol was 5·07 ± 4·08% (±SD; range 1·77-10·1%). Although no correlation was seen between TC and the fraction (%) of free serum cortisol, a positive correlation existed between baseline total and free cortisol (R = 0·539 P = 0·01), as well as between peak ACTH-stimulated total and free cortisol (R = 0·619; P = 0·01). There was no correlation between baseline salivary cortisol and serum free cortisol and between peak ACTH-stimulated salivary and serum free cortisol. Using the lowest attained peak serum free cortisol in subjects whose TC response to ACTH was normal (≥ 500 nM), the minimal 'pass' level for normal serum free cortisol response to 1 μg ACTH was set at 25·0 nM. Five of the 19 subjects showing subnormal TC response to 1 μg ACTH had normal serum free cortisol response., Conclusions: Discrepancies between the peak free and TC were noted mostly for subjects whose ACTH-stimulated TC peaked between 440 and 580 nm. At this range, the measurement of serum free cortisol allows further refinement of the assessment of borderline responses to 1-μg ACTH., (© 2011 Blackwell Publishing Ltd.)
- Published
- 2011
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43. Renal and systemic effects of endothelin-1 in diabetic-hypertensive rats.
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Hofman C, Rosenthal T, Winaver J, Rubinstein I, Ramadan R, Stern N, Limor R, Awad H, and Abassi Z
- Subjects
- Animals, Base Sequence, Blood Pressure drug effects, Blood Pressure physiology, DNA Primers genetics, Diabetes Mellitus, Experimental genetics, Endothelin A Receptor Antagonists, Endothelin B Receptor Antagonists, Endothelin-1 genetics, Gene Expression, Hemodynamics drug effects, Hypertension genetics, Kidney metabolism, RNA, Messenger genetics, RNA, Messenger metabolism, Rats, Rats, Inbred SHR, Rats, Inbred Strains, Receptor, Endothelin A genetics, Receptor, Endothelin B genetics, Diabetes Mellitus, Experimental complications, Diabetes Mellitus, Experimental physiopathology, Endothelin-1 pharmacology, Endothelin-1 physiology, Hemodynamics physiology, Hypertension complications, Hypertension physiopathology, Renal Circulation drug effects, Renal Circulation physiology
- Abstract
The Cohen-Rosenthal Diabetic Hypertensive rat (CRDH) is a unique animal model in which genetic hypertension and diabetes developed after crossbreeding of Cohen diabetic rats sensitive substrain (CDR) and spontaneously hypertensive rats (SHR). The present study examined: 1) The acute effects of ET-1 on the systemic and renal hemodynamics in CRDH rats, CDR, and SHR; 2) The expression of ET-1 and its receptors in the renal tissue of CRDH rats. Intravenous injection of ET-1 (1.0 nmol/kg) into anesthetized SHR rats resulted in a significant immediate depressor response (mean arterial pressure (MAP) decreased from 165 ± 3 to 124 ± 12 mmHg, p < 0.0001) followed by a minor hypertensive phase (MAP increased to 170 ± 2 mmHg). Simultaneously, the administration of ET-1 caused a significant decrease in renal blood flow (RBF) from 5.8 ± 0.9 ml/min to 3.2 ± 0.5 ml/min (p = 0.026). These responses were blunted in CRDH rats and CDR. Analysis of intra-renal blood flow by laser-Doppler in CRDH rats revealed that ET-1 injection caused a decrease in cortical blood flow (Δ = -12 ± 2.9%). However, in contrast to its well-known renal medullary vasodilatory effect, ET-1 produced a significant decline in the medulla blood flow (Δ = -17.5 ± 3.4%) (p = 0.0125). These findings suggest that CDR and CRDH rats have reduced sensitivity to vascular and renal action of ET-1. Furthermore, in the CRDH rats, the expected ET-1-induced medullary vasodilatation was abolished and even reversed into prolonged vasoconstriction.
- Published
- 2011
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44. Telmisartan ameliorates hyperglycemia and metabolic profile in nonobese Cohen-Rosenthal diabetic hypertensive rats via peroxisome proliferator activator receptor-gamma activation.
- Author
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Younis F, Stern N, Limor R, Oron Y, Zangen S, and Rosenthal T
- Subjects
- Adiponectin blood, Animals, Benzimidazoles therapeutic use, Benzoates therapeutic use, Blood Pressure drug effects, Humans, Insulin blood, Insulin Resistance, Leptin blood, Rats, Rats, Inbred SHR, Rosiglitazone, Telmisartan, Thiazolidinediones pharmacology, Tumor Necrosis Factor-alpha blood, Weight Gain drug effects, Angiotensin II Type 1 Receptor Blockers pharmacology, Benzimidazoles pharmacology, Benzoates pharmacology, Hyperglycemia drug therapy, Hypertension drug therapy, PPAR gamma drug effects
- Abstract
The importance of hypertension treatment has expanded beyond blood pressure management to include additional risk factors, mainly diabetes. It was considered of interest to test the effect of telmisartan, an angiotensin receptor 1 antagonist and peroxisome proliferator activator receptor-gamma partial agonist, on Cohen-Rosenthal diabetic hypertensive nonobese (CRDH) rats, a unique model combining both pathologies. Its effect was examined on fat-derived and inflammatory agents in CRDH. To determine the extent of the drug's peroxisome proliferator activator receptor-gamma modulating beneficial metabolic actions, results were compared with those obtained with valsartan and rosiglitazone in CRDH and Cohen diabetic rat (CDR). Telmisartan and valsartan were given in drinking water at 3 and 12 mg/kg/d, whereas rosiglitazone (3 mg/kg/d) was given as food admixture for a period of 5 months. Blood pressure, glucose, insulin, adiponectin, leptin, and tumor necrosis factor alpha were examined. Telmisartan and valsartan significantly (P < .01) reduced blood pressure, whereas telmisartan and rosiglitazone considerably reduced blood glucose levels to normoglycemic levels (P < .01) in these 2 strains. Insulin levels were not affected by telmisartan and valsartan but were slightly reduced by rosiglitazone in CDR. In contrast to valsartan, adiponectin was significantly (60%, P < .01) increased by telmisartan in both CDR and CRDH, whereas rosiglitazone induced a 60% and 180% increase in CRDH and CDR animals, respectively, on day 30 of treatment. Co-treatment with GW9662 averted telmisartan-induced rise of adiponectin. Tumor necrosis factor alpha declined in telmisartan-treated rats, less so with rosiglitazone, but not valsartan. Telmisartan also induced downsizing of epididymal adipocytes compared with valsartan. Leptin levels were significantly increased by valsartan (P < .05) but reduced by telmisartan and rosiglitazone. The telmisartan-induced increase in adiponectin was most probably associated with a decrease in glucose and tumor necrosis factor alpha levels. Therefore, in addition to its hypotensive effect, telmisartan demonstrated beneficial thiazolidinedione-like effects., (Copyright 2010 Elsevier Inc. All rights reserved.)
- Published
- 2010
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45. Follicular fluid levels of anti-Mullerian hormone as a predictor of oocyte maturation, fertilization rate, and embryonic development in patients with polycystic ovary syndrome.
- Author
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Mashiach R, Amit A, Hasson J, Amzalzg S, Almog B, Ben-Yosef D, Lessing JB, Limor R, and Azem F
- Subjects
- Adult, Anti-Mullerian Hormone metabolism, Female, Fertilization physiology, Fertilization in Vitro methods, Follicular Fluid metabolism, Humans, Infertility, Female etiology, Infertility, Female metabolism, Infertility, Female therapy, Oogenesis physiology, Predictive Value of Tests, Pregnancy, Prognosis, Anti-Mullerian Hormone analysis, Embryonic Development physiology, Follicular Fluid chemistry, Infertility, Female diagnosis, Oocytes physiology, Polycystic Ovary Syndrome complications, Polycystic Ovary Syndrome diagnosis, Polycystic Ovary Syndrome metabolism, Polycystic Ovary Syndrome therapy, Pregnancy Rate
- Abstract
Objective: To test whether the follicular fluid (FF) concentration of anti-Mullerian hormone (AMH) is associated with oocyte maturation, fertilization rate, and embryonic development in patients with polycystic ovary syndrome (PCOS) undergoing IVF., Design: Prospective., Setting: Academic assisted reproductive technology program., Patient(s): Twenty-two samples of FF from 11 patients with PCOS who underwent IVF/ET were analyzed for AMH levels (group A). Twelve women with normal ovulatory cycles served as a control group (group B). The oocytes and preembryos were closely followed until ET., Method(s): FF was obtained at oocyte retrieval for IVF/intracytoplasmic sperm injection. AMH levels were studied using immunoenzymometric assay., Intervention(s): None., Main Outcome Measure(s): FF, AMH levels, oocyte maturation, fertility rate, and embryonic cleavage rate., Result(s): The mean FF AMH level was 57.3 +/- 79.5 pmol/mL in group A, compared with 70 +/- 120.14 pmol/mL in group B. In group A, the mean AMH level of good-quality embryos was 37.4 +/- 23.4 pmol/mL, compared with 61.9 +/- 102 pmol/mL in a the poor-quality subgroup. No significant correlation was observed between FF AMH levels and oocyte maturation, fertilization, or cleavage rate., Conclusion(s): This study suggests that there is an association between FF AMH levels and the quality of embryos in patients with PCOS. However, owing to large variance and the number of participants, no statistical significance was reached. The degree of maturation of retrieved oocytes, as well as the success of fertilization, was not found to correlate with FF AMH., (Copyright 2010 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.)
- Published
- 2010
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46. Aldosterone up-regulates 12- and 15-lipoxygenase expression and LDL oxidation in human vascular smooth muscle cells.
- Author
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Limor R, Kaplan M, Sharon O, Knoll E, Naidich M, Weisinger G, Keidar S, and Stern N
- Subjects
- 12-Hydroxy-5,8,10,14-eicosatetraenoic Acid metabolism, Aldosterone pharmacology, Arachidonate 12-Lipoxygenase genetics, Arachidonate 15-Lipoxygenase genetics, Cell Line, ErbB Receptors metabolism, Humans, Hydroxyeicosatetraenoic Acids metabolism, Mineralocorticoid Receptor Antagonists, Mitogen-Activated Protein Kinase Kinases metabolism, Muscle, Smooth, Vascular drug effects, Muscle, Smooth, Vascular metabolism, Myocytes, Smooth Muscle drug effects, Oxidation-Reduction, Receptors, Mineralocorticoid metabolism, Up-Regulation, Aldosterone metabolism, Arachidonate 12-Lipoxygenase metabolism, Arachidonate 15-Lipoxygenase metabolism, Lipoproteins, LDL metabolism, Myocytes, Smooth Muscle metabolism
- Abstract
Several lines of evidence suggest that aldosterone excess may have detrimental effects in the cardiovascular system, independent of its interaction with the renal epithelial cells. Here we examined the possibility that aldosterone modulates 12- and/or 15-lipoxygenase (LO) expression/activity in human vascular smooth muscle cells (VSMC), in vitro, thereby potentially contributing to both vascular reactivity and atherogenesis. Following 24 h treatment of VSMC with aldosterone (1 nmol/L), there was a approximately 2-fold increase in the generation rate of 12 hydroxyeicosatetraenoic acid (12-HETE), 70% increase in platelet type 12-LO mRNA expression (P < 0.001) along with a approximately 3-fold increase in 12-LO protein expression, which were blocked by the mineralocorticoid receptor (MR) antagonists spironolactone (100 nmol/L) and eplerelone (100 nmol/ml). Additionally, aldosterone (1 nmol/L; 24 h) increased the production of 15-HETE (50%; P < 0.001) and the expression of 15-LO type 2 mRNA (50%; P < 0.05) (in VSMC). Aldosterone also increased the 12- and 15-LO type 2 mRNA expression in a line of human aortic smooth muscle cells (T/G HA-VSMC) (60% and 50%, respectively). Aldosterone-induced 12- and 15-LO type 2 mRNA expressions were blocked by the EGF-receptor antagonist AG 1478 and by the MAPK-kinase inhibitor UO126. Aldosterone-treated VSMC also showed increased LDL oxidation, (approximately 2-fold; P < 0.001), which was blocked by spironolactone. In conclusion, aldosterone increased 12- and 15-LO expression in human VSMC, in association with increased 12- and 15-HETE generation and enhanced LDL oxidation and may directly augment VSMC contractility, hypertrophy, and migration through 12-HETE and promote LDL oxidation via the pro-oxidative properties of these enzymes.
- Published
- 2009
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47. Effect of testosterone replacement therapy on arterial stiffness in older hypogonadal men.
- Author
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Yaron M, Greenman Y, Rosenfeld JB, Izkhakov E, Limor R, Osher E, Shenkerman G, Tordjman K, and Stern N
- Subjects
- Age Factors, Age of Onset, Aged, Arteries drug effects, Blood Flow Velocity drug effects, Blood Pressure drug effects, Follicle Stimulating Hormone blood, Hormone Replacement Therapy, Humans, Hypogonadism blood, Hypogonadism epidemiology, Luteinizing Hormone blood, Male, Middle Aged, Prolactin blood, Testosterone blood, Hypogonadism drug therapy, Hypogonadism physiopathology, Testosterone pharmacology, Testosterone therapeutic use, Vascular Resistance drug effects
- Abstract
Objective: To assess arterial stiffness in a cohort of hypogonadal males and to investigate the effect of testosterone replacement therapy on arterial properties in this specific group., Design: Eighteen male patients with untreated acquired hypogonadism due to either adult-onset idiopathic hypogonadotropic hypogonadism (n=9) or pituitary tumor (n=9) and 12 age-, sex, and weight-matched eugonadal healthy controls were recruited for the study. Arterial properties, plasma glucose, lipid profile, total, and bioavailable testosterone (BT) levels were measured in fasting state. In the hypogonadal subjects, the effect of transdermal testosterone replacement therapy on arterial properties was studied by repeat noninvasive measurements at baseline, as well as 48 h and 90 days following the initiation of treatment., Methods: Arterial stiffness was evaluated using applanation tonometry and pulse wave analysis by three different standard devices that assess various measures of arterial stiffness: pulse wave velocity (PWV), augmentation index (AIx), and large/small artery compliance (C1 and C2)., Results: Age- and blood pressure-adjusted PWV was significantly higher in hypogonadal men (8.90+/-2.29 vs 6.78+/-1.16 m/s in the control group; P=0.025). Testosterone therapy increased BT level from 2.01+/-1.04 to 4.68+/-2.43 and 7.83+/-6.2 nmol/l after 48 h and 3 months respectively (P=0.001). PWV decreased from 8.9+/-2.29 to 8.24+/-1.39 and 8.25+/-1.82 m/s after 48 h and 3 months of treatment respectively (P=0.03)., Conclusions: Male hypogonadism is associated with increased PWV, which is rapidly but incompletely ameliorated by normalization of circulating testosterone levels.
- Published
- 2009
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48. Testosterone is a strong correlate of ghrelin levels in men and postmenopausal women.
- Author
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Greenman Y, Rouach V, Limor R, Gilad S, and Stern N
- Subjects
- Adult, Aged, Body Mass Index, Estradiol blood, Female, Humans, Male, Middle Aged, Postmenopause, Premenopause, Sex Characteristics, Ghrelin blood, Testosterone blood
- Abstract
Background/aims: The secretion and regulation of several hormones such as leptin and growth hormone (GH) is sexually dimorphic. Gender effects on ghrelin, a hormone involved in the regulation of GH secretion and appetite control, are controversial. Our aim was to study the relationship between plasma ghrelin and serum sex steroid hormone concentrations., Methods: Forty-five subjects (19 men, 12 premenopausal and 14 postmenopausal women) were evaluated at the Institute of Endocrinology and Metabolism, Tel Aviv Sourasky Medical Center, Israel. After an overnight fast, blood samples were collected for measurements of ghrelin, testosterone, bioavailable testosterone (BT) and estradiol. Statistical analysis was performed with adjustments for age and body mass index. Results are given as mean +/- standard deviation., Results: Ghrelin levels were significantly higher in women (510 +/- 489 pg/ml) than in men (319 +/- 237 pg/ml; p = 0.02). There was a positive correlation between ghrelin and both total testosterone (r = 0.5, p = 0.039) and BT (r = 0.719, p = 0.0011) in male subjects. In premenopausal women, no significant correlations were found between ghrelin and testosterone or BT (r = -0.39, p = 0.2). In contrast, ghrelin strongly and positively correlated with total testosterone (r = 0.7, p = 0.01) and BT (r = 0.821, p = 0.001) in postmenopausal women. Estradiol and ghrelin were positively correlated in the group as a whole (r = 0.356, p = 0.019), but not significantly when analyzed separately by gender., Conclusions: Circulating ghrelin in humans is sexually dimorphic. Testosterone correlates positively with ghrelin levels in men and postmenopausal women.
- Published
- 2009
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49. Lipoxygenase metabolites are mediators of PTH-dependent human osteoblast growth.
- Author
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Somjen D, Tordjman K, Katzburg S, Knoll E, Sharon O, Limor R, Naidich M, Naor Z, Hendel D, and Stern N
- Subjects
- Arachidonate 12-Lipoxygenase genetics, Arachidonate 15-Lipoxygenase genetics, Cells, Cultured, DNA biosynthesis, Enzyme Inhibitors metabolism, Extracellular Signal-Regulated MAP Kinases metabolism, Female, Humans, Isoenzymes genetics, MAP Kinase Kinase 1 antagonists & inhibitors, MAP Kinase Kinase 1 metabolism, Osteoblasts cytology, Protein Kinase C antagonists & inhibitors, Protein Kinase C metabolism, 12-Hydroxy-5,8,10,14-eicosatetraenoic Acid metabolism, Arachidonate 12-Lipoxygenase metabolism, Arachidonate 15-Lipoxygenase metabolism, Hydroxyeicosatetraenoic Acids metabolism, Isoenzymes metabolism, Osteoblasts physiology, Parathyroid Hormone metabolism
- Abstract
PTH-induced osteoblast proliferation may contribute to its anabolic effects in bone. Since PTH-dependent osteoblast-like cell (Ob) growth is mediated via protein kinase C (PKC) and MAP kinase-kinase (MEK) and since lipoxygenase (LO) products activate PKC in a number of cell types, we assessed the expression of LO pathways in primary human cultured Ob. Ob from pre- or post-menopausal women were cultured and were treated with PTH and assayed for the expression of 12-LO and both type I and type II 15-LO mRNA and for the release their enzymatic products, 12- and 15-hydroxyeicosatetraenoic acid (HETE). Cells were also treated with PTH for stimulation DNA synthesis. First, Ob express platelet type- 12-LO and both type I and type II 15-LO mRNA and release their enzymatic products, 12- and 15-hydroxyeicosatetraenoic acid (HETE). Second, in female Ob, PTH induced a rapid increase in 12-HETE (50 fold increase) and 15-HETE (80 fold increase) and increased the expression of 12-LO mRNA but not of the two isoforms of 15-LO. PTH as well as 12 and 15-HETE stimulated DNA synthesis in Ob. The LO inhibitor baicalein inhibited PTH-stimulated DNA synthesis, which was reversed in the presence of either 12- or 15-HETE. A PKC inhibitor (bisindolylmaleimide I) as well as a MEK inhibitor (PD 98059) completely inhibited the stimulation of DNA synthesis by PTH, 12-HETE and the combination of PTH and 12-HETE. In contrast, 15-HETE-induced DNA synthesis was not abolished by these inhibitors. Further, 15-HETE partially restored the stimulatory effect of PTH on DNA synthesis in cells treated with PKC or MEK inhibitors. Finally, PTH- induced ERK1/2 phosphorylation, was blocked by a MEK inhibitor. These results demonstrate a novel mechanism of PTH-induced human bone cell proliferation operating through LO enzymes.
- Published
- 2008
- Full Text
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50. Lipoxygenase-derived metabolites are regulators of peroxisome proliferator-activated receptor gamma-2 expression in human vascular smooth muscle cells.
- Author
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Limor R, Sharon O, Knoll E, Many A, Weisinger G, and Stern N
- Subjects
- 12-Hydroxy-5,8,10,14-eicosatetraenoic Acid metabolism, Arachidonate 12-Lipoxygenase genetics, Arachidonate 15-Lipoxygenase genetics, Cells, Cultured, Gene Expression drug effects, Gene Expression physiology, Humans, Hydroxyeicosatetraenoic Acids metabolism, Hypoglycemic Agents pharmacology, PPAR gamma metabolism, RNA, Messenger metabolism, Rosiglitazone, Thiazolidinediones pharmacology, Umbilical Cord cytology, Up-Regulation physiology, Arachidonate 12-Lipoxygenase metabolism, Arachidonate 15-Lipoxygenase metabolism, Muscle, Smooth, Vascular cytology, Muscle, Smooth, Vascular enzymology, PPAR gamma genetics
- Abstract
Background: Peroxisome proliferator-activated receptor-gamma (PPAR-gamma) is a member of the nuclear receptor family that has been implicated in cell differentiation and proliferation, glucose metabolism, macrophage development, and inflammatory responses. PPAR-gamma can be activated by a range of synthetic substances and also by products of lipid oxidation such as oxidized low-density lipoprotein, 13-hydroxyoctadecadienoic acid (13-HODE) and 15-hydroxyeicosatetraenoic acid (15-HETE). Since 12- and 15-lipoxygenase (12- and 15-LO) are expressed in human vascular smooth muscle cells (VSMCs), we set out to investigate the possible relation between PPAR-gamma and LO system in these cells., Methods: In vitro experiments in human VSMC using standard methods., Results: The LO products, 12-HETE (10(-7) mol/l), 15-HETE (10(-7) mol/l) and 13-HODE (10(-7) mol//l) increased the expression of PPAR-gamma-2 messenger RNA (mRNA) in VSMC (by 100, 50, and 100%, respectively. Rosiglitazone (1-10 micromol/l) was found to upregulate both the mRNA expression of two LO enzymes, platelet-type 12-lipoxygenase (12-LO; +70%) and 15-lipoxygenase type 2 (15-LO; +60%), and the secretion of their eicosanoid products 12- and 15-HETE. In addition, rosiglitazone-induced a threefold increase in PPAR-gamma-2 mRNA expressions and modest 50% rise in PPAR-gamma-1 mRNA expression. The effect of rosiglitazone on PPAR-gamma-2 could be entirely blocked by the LO inhibitor baicalein and restored by the addition of exogenous 12-HETE., Conclusions: These results suggest a novel amplification cycle in which PPAR-gamma activation induces production of 12- and 15-LO-derived metabolites which in turn feed back to upregulate PPAR-gamma-2's own expression. The implications of this link in VSMC pathophysiology remain to be elucidated.
- Published
- 2008
- Full Text
- View/download PDF
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