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Background Glucagon-like peptide-1 (GLP-1) is a gut incretin hormone that stimulates insulin secretion and may affect the inflammatory pathways involved in diabetes mellitus. Calcitriol, an active form of vitamin D, plays an important role in renal, endothelial and cardiovascular protection. We evaluated the anti-inflammatory and histologic effects of a GLP-1 analogue (liraglutide) and of calcitriol in a db/db mouse diabetes model and in endothelial cells exposed to a diabetes-like environment. Methods Diabetic db/db mice were treated with liraglutide and calcitriol for 14 weeks, after which the kidneys were perfused and removed for mRNA and protein analysis and histology. Endothelial cells were stimulated with advanced glycation end products (AGEs), glucose, liraglutide and calcitriol. Total RNA and protein were extracted and analysed for the expression of selected inflammatory markers. Results Typical histological changes, glomerular enlargement and mesangial expansion were seen in db/db mice compared with control mice. Glomerular hypertrophy was ameliorated with liraglutide, compared with db/db controls. Liraglutide up-regulated endothelial nitric oxide synthase protein expression compared with the db/db control group and down-regulated p65 protein expression. Calcitriol did not further improve the beneficial effect observed on protein expression. In endothelial cells, liraglutide treatment exhibited a dose-dependent ability to prevent an inflammatory response in the selected markers: thioredoxin-interacting protein, p65, IL6 and IL8. In most gene and protein expressions, addition of calcitriol did not enhance the effect of liraglutide. Conclusions The GLP-1 analogue liraglutide prevented the inflammatory response observed in endothelial cells exposed to a diabetes-like environment and in db/db mice at the level of protein expression and significantly ameliorated the glomerular hypertrophy seen in the diabetic control group. Copyright © 2016 John Wiley & Sons, Ltd.

Glucagon-like peptide-1 (GLP-1) is a gut incretin hormone that stimulates insulin secretion and may affect the inflammatory pathways involved in diabetes mellitus. Calcitriol, an active form of vitamin D, plays an important role in renal, endothelial and cardiovascular protection. We evaluated the anti-inflammatory and histologic effects of a GLP-1 analogue (liraglutide) and of calcitriol in a db/db mouse diabetes model and in endothelial cells exposed to a diabetes-like environment.Diabetic db/db mice were treated with liraglutide and calcitriol for 14 weeks, after which the kidneys were perfused and removed for mRNA and protein analysis and histology. Endothelial cells were stimulated with advanced glycation end products (AGEs), glucose, liraglutide and calcitriol. Total RNA and protein were extracted and analysed for the expression of selected inflammatory markers.Typical histological changes, glomerular enlargement and mesangial expansion were seen in db/db mice compared with control mice. Glomerular hypertrophy was ameliorated with liraglutide, compared with db/db controls. Liraglutide up-regulated endothelial nitric oxide synthase protein expression compared with the db/db control group and down-regulated p65 protein expression. Calcitriol did not further improve the beneficial effect observed on protein expression. In endothelial cells, liraglutide treatment exhibited a dose-dependent ability to prevent an inflammatory response in the selected markers: thioredoxin-interacting protein, p65, IL6 and IL8. In most gene and protein expressions, addition of calcitriol did not enhance the effect of liraglutide.The GLP-1 analogue liraglutide prevented the inflammatory response observed in endothelial cells exposed to a diabetes-like environment and in db/db mice at the level of protein expression and significantly ameliorated the glomerular hypertrophy seen in the diabetic control group. Copyright © 2016 John WileySons, Ltd.

Fibroblast growth factor (FGF) 23 and Klotho are two factors associated with several metabolic disorders. Similar to humans, accelerated aging processes characterized by chronic vascular disease, bone demineralization, skin atrophy and emphysema have been recognized in FGF23-null mice and Klotho-deficient mice. The role of these factors in the control of mineral metabolism homeostasis have been shown recently, particularly at the level of parathyroid cells and also in modulating active vitamin D production, two phenomena which are relevant in the presence of chronic kidney disease. In addition, the hormonal affect of circulating FGF23 and Klotho proteins on vascular reactivity, either directly on endothelial cell functions or indirectly by modulating the brain endothelin-1-dependent sympathetic nervous system activity, has contributed to understanding their role in the pathophysiology of hypertension and atherosclerotic vasculopathies. Consequently, very recent clinical investigations seem to confirm the involvement of Klotho in modulating the severity and prognosis of human cardiovascular (CV) disorders and longevity. The present review reports data related to the possible interactive effects of Klotho and FGF23 on the prognosis of renal and CV diseases.

Background Recent studies have suggested that vitamin D and an imbalance in calcium homeostasis may have an impact on the cardiovascular system. The aim of this study was to assess the impact of different concentrations of extracellular Ca(2+) on human umbilical vein cord endothelial cells (HUVEC) by measuring its effect on parameters involved in the pathogenesis of vascular inflammatory responses. Methods HUVEC were grown in the 3.5, 4.5 or 5.8 mg/dL concentration of extracellular Ca(2+) for 2-3 weeks. Expression of adhesion molecules was analysed by flow cytometry. Endothelial nitric oxide synthase (eNOS), receptor of advanced glycation end-product (RAGE) and interleukin-6 (IL-6) mRNA expressions were determined by real-time PCR. eNOS, inhibitor kappa Balpha (IkappaBalpha) and phosphorylated IkappaBalpha protein levels by Western blot, eNOS activity by conversion of [(14)C]-arginine to [(14)C]-citrulline, IL-6 and osteoprotegerin (OPG) secretion by ELISA and DNA-binding activity of nuclear factor kappa B (NFkappaB)-p65 were assayed colorimetrically in nuclear extracts. Results In the presence of low Ca(2+) (3.5 mg/dL), protein expressions and activity of eNOS were diminished, while the protein expressions of intercellular adhesion molecule-1 (ICAM-1), as well as the mRNA expressions of RAGE and IL-6, were elevated. The protein secretions of IL-6 and OPG were also stimulated in low Ca(2+) concentration. At this concentration, the DNA-binding activity of NFkappaB was enhanced, probably due to the decreased level of IkappaBalpha. Conclusions These results suggest that lower extracellular ionized Ca(2+) may play a relevant role in modifying endothelial cells functions.

BACKGROUND Parathyroid hormone (PTH), the major systemic calcium regulating hormone has been implicated in the development of hypertension and the occurrence of uraemic vascular changes. As nitric oxide synthase (NOS) is involved in the production of nitric oxide, and acute PTH effect is characterized by vasodilation, the effect of PTH on the endothelial NOS (eNOS) system was measured in cultured human umbilical cord vein endothelial cells (HUVEC) and the pathways possibly involved were studied. METHODS The presence of the PTH receptor-1 (PTHR1) on the HUVEC membrane was examined by RT-PCR, immunocytochemistry and western blot. HUVEC were stimulated with 10(-12) to 10(-10) mol/l PTH. The eNOS mRNA expression was established by RT-PCR and the eNOS protein levels were determined by western blot. The eNOS activity was measured by the conversion of [(14)C]arginine to [(14)C]citrulline. RESULTS PTHR1 has been found to be expressed in HUVEC and its expression is depressed by increasing concentrations of PTH. PTH induced a significant increase in eNOS mRNA (10(-11) mol/l: 1.87 +/- 0.16, P = 0.012; 10(-10) mol/l: 1.96 +/- 0.28, P = 0.007, fold of control), and protein expression. The eNOS activity was also significantly stimulated (10(-11) mol/l: 1139 +/- 203; 10(-10) mol/l: 1323 +/- 216 vs control: 621 +/- 154 cpm/150 mug protein, P < 0.01). The addition of calphostin C (PKC inhibitor) or Rp-cAMP (PKA inhibitor) reduced the eNOS mRNA, protein expression and activity of PTH-stimulated HUVEC. The combined treatment of calphostin C and Rp-cAMP abolished the eNOS protein expression and activity. CONCLUSION PTH induces an increased activity of the eNOS system; probably both PKA and PKC pathways are involved in this activation. Such data may explain the vasodilation observed after acute treatment with PTH.

Background. Chronic treatment with candesartan cilexetil (C) improves the outcome of rats after 5/6 nephrectomy (Nx). Tetrahydrobiopterin (BH4), an essential cofactor for appropriate endothelial nitric oxide synthase (eNOS) activity, prevents an increase in blood pressure (BP) in Nx rats when given immediately after surgery. In the present study, we evaluated the renoprotective effect of a combined treatment. Methods. Five groups of rats were studied: SHAM (sham-operated rats, n ¼ 12); SNx (untreated 5/6 nephrectomized rats, n ¼ 15); C (SNx rats treated with candesartan cilexetil, 5 mg/kg/day per os, n ¼ 11); C þ BH4 (SNx rats treated with candesartan cilexetil and BH4, 10 mg/kg/day intraperitoneally, n ¼ 11); and BH4 (SNx rats treated with BH4, 10 mg/ kg/day intraperitoneally, n ¼ 11). Treatment began 30 days after surgery, when hypertension and renal insufficiency have developed. This day was considered as day 1 of treatment for statistical comparisons. The study was continued until 50% mortality was achieved in the SNx rats (4 months after surgery). Results. The survival rates were 100% for SHAM, 47% for SNx, 50% for BH4, 64% for C and 80% for C þ BH4 (P < 0.05 vs all). Untreated Nx rats developed hypertension, proteinuria (UP) and severe renal insufficiency. Mortality was associated with a lower renal function and increased urine protein excretion. In C and C þ BH4 rats, systolic blood pressure (SBP) decreased significantly. BH4 alone had a mild nonsignificant effect on SBP. C and C þ BH4 treatments attenuated significantly the increase in proteinuria found in SNx animals. The weight of the remnant kidneys as well as the severity of glomerulosclerosis were significantly lower in the C þ BH4 rats. Conclusion. This study shows that in subnephrectomized rats, addition of BH4 to a treatment with candesartan had an additive renoprotective effect. The mechanism of such action may include a better control of BP associated with a blockade of actions of angiotensin II (Ag II), an improvement in nitric oxide synthesis and a balanced redox.

Background Current blood pressure (BP) classification is based on the recent recommendations of the Joint National Committee on Prevention, Detection, Evaluation and Treatment of High Blood Pressure (JNC-7) and the 2003 European Society of Hypertension–European Society of Cardiology Guidelines for the Management of Arterial Hypertension. The JNC-7 introduced a new concept, prehypertension, and recommended health-promoting lifestyle modifications for these individuals. Obesity is also recognized as a major risk factor for the development of hypertension. We aimed to determine the prevalence of hypertension and obesity in a large cohort of adolescents and to assess whether prehypertension and body mass index (BMI) increase with increasing age. Methods A cross-sectional population-based study was performed using data collected during 1996 to 2002 in an army recruitment examination of 560,588 Israeli individuals 16.5 to 19 years of age. The subjects were divided according to gender and stratified by increasing 6-month intervals into five groups. Prehypertension was defined as BP 120 to 139 / 80 to 89 mm Hg. Overweight was defined as BMI 25 to ≤30 and obesity as BMI >30 kg/m2. Results Mean systolic BP (SBP) and diastolic BP (DBP) were significantly higher in male subjects for all groups. By applying the JNC-7 criteria, 56.8% of male subjects and 35.8% of female subjects would be considered prehypertensive. There was a statistically significant increase in the mean SBP and DBP with age and BMI. Among male subjects 10.9% were overweight and 3.3% were obese; among female subjects, 11.1% were overweight and 3.2% were obese. The BMI did not increase with increasing age. The prevalence of prehypertension was significantly higher in obese subjects. Conclusions Prehypertension is very common among Israeli adolescents. A substantial number of adolescents exhibit a BMI greater than normal. As both of these factors are known to be asssociated with increased cardiovascular risk, early institution of healthful lifestyle changes in a large proportion of this age group is recommended.

Background: Previous studies have shown that endothelial dysfunction after 5/6 nephrectomy (5/6 Nx) in rats is associated with decreased nitric oxide (NO) bioavailability and increased vascular superoxide production. Blood pressure is significantly increased by day 10 after surgery. Tetrahydrobiopterin (BH4) is a key cofactor of NO synthase. Suboptimal levels of BH4 result in uncoupling of NO synthase, low NO synthesis and augmented production of superoxide anions. The aim of this study was to evaluate whether BH4 supplementation may improve NO production and prevent the increase of blood pressure after 5/6 Nx. Methods: Three groups were evaluated: 5/6 Nx (untreated rats), BH4 (5/6 Nx rats treated with BH4, 10 mg/day i.p. for 10 days) and L-ARG (5/6 Nx rats treated with L-arginine, 260 mg/kg BW, p.o for 10 days). Systolic blood pressure (SBP), urinary nitrate excretion (UNO3) and creatinine clearance (CCR) were measured before surgery and on days 3 and 10 after surgery. Endothelial NO synthase (eNOS) protein content of mesenteric resistance vessels was measured at the end of the study. Results: SBP increased from 107 ± 2 to 127 ± 4 mm Hg in untreated 5/6 Nx rats (p < 0.01). By contrast, rats treated with BH4 or L-ARG remained normotensive. Ten days after 5/6 Nx, creatinine clearance decreased similarly in all groups. Both BH4 and L-ARG supplementation markedly increased UNO3 excretion. The mesenteric vascular expression of eNOs protein was significantly higher in BH4 but not in L-ARG, compared with Nx rats. Conclusions: BH4 supplementation prevents the earlier increase in blood pressure observed in rats after 5/6 Nx, possibly by upregulating eNOS in resistance vessels.

Endothelial dysfunction and hypertension in 5/6 nephrectomized rats are mediated by vascular superoxide.BackgroundNitric oxide inactivation by superoxide impairs endothelium-dependent vasodilation and plays a role in various forms of hypertension. Almost no data exist regarding hypertension secondary to chronic renal failure. Previous studies have shown that endothelium-related relaxations, secondary to decreased nitric oxide bioactivity, are impaired in resistance vessels from rats 3 to 10 days after renal mass reduction (RMR).MethodsThe membrane-permeable superoxide dismutase (SOD)-mimetic (tempol) was administered IP (1.5 mmol/kg/day for 10 days) to RMR rats and sham-operated controls (SN). Systolic blood pressure (SBP) was measured by tail cuff manometry at days 0, 3, 6 and 10. The increase of flow induced by acetylcholine (10-6 mol/L) was measured in isolated perfused mesenteric arteries from RMR and SN rats pre-contracted with noradrenaline (1 to 5 μmol/L), with or without exogenous SOD. Plasma levels of advanced oxidative protein products (AOPPs; chloramine-T equivalents) were measured in SN and RMR rats.ResultsTempol prevented the increase of SBP: 118 ± 2.2mm Hg at baseline and 122 ± 1.6mm Hg at 10 days in tempol-treated vs 118.14 ± 1.65mm Hg at baseline and 145 ± 7.69mm Hg at 10 days in untreated RMR rats (P < 0.01). Responsiveness to acetylcholine was reduced in RMR rats (peak flow increase: 139 ± 7.8% vs. 176 ± 11% in SN, P = 0.028 at 3 days and 140 ± 6.4% vs. 187 ± 16.9% in SN at 10 days, P = 0.007). In arteries pre-incubated with SOD (200 U/mL) the peak flows were 175 ± 9.4% at 3 days and 157 ± 5.8% at 10 days (P = 0.007 and P = 0.051, respectively, vs. control RMR vessels). AOPP values were significantly increased in plasma from RMR rats 3 days after 5/6 nephrectomy (747 ± 107 vs. 481 ± 77 μmol/L, P < 0.05) but returned to normal by day 10. AOPP levels were not significantly reduced by tempol.ConclusionsIncreased vascular superoxide production plays a central role in the development of vascular endothelial dysfunction and hypertension early after 5/6 nephrectomy.

Background. The renoprotective effect of ACE inhibition in chronic renal disease is well established but the studies on effects of calcium antagonists on progression of renal disease and on proteinuria have given varying results. Methods. We conducted an open long-term randomized prospective multi-centre study comparing the combination of ramipril (R) and felodipine ER (F) with either drug alone in non-diabetic renal disease. Included were patients with uncontrolled hypertension (diastolic blood pressure (DBP)) P95 mmHg on treatment with a diuretic and a beta-blocker. Fiftyone patients received the combination of R and F, 54 patients R, and 53 patients F. The treatment goal was aD BP-90 mmHg and a similar BP reduction in the three groups. Mean doses at the last visit were 5q5, 10 and 9 mg, respectively, after a mean treatment time of nearly 2 years. The progression of renal impairment was studied by serial measurements of serum creatinine, iohexol clearance, and albuminuria. Results. The reduction in supine systolic (S) BP and DBP expressed as median values were 19.0u14.5, 14.3u15.0 and 13.5u13.3 mmHg in the RqF, R, and F groups, respectively. There was no significant difference between the groups. When correction for the acute drug effect was performed the RqF group had a slower progression rate of the renal disease (loss of glomerular filtration rate (GFR) mluminuyear) compared with the F group (P-0.05) but not to the R group (P)0.20). There was a rise in albuminuria after 2 years in the F group (P-0.05), but no significant change was found in the other groups. Conclusions. In patients with non-diabetic renal disease the combination of an ACE inhibitor and a calcium antagonist in reduced doses used in addition to baseline therapy with beta-blockers and diuretics, tended to cause a better BP reduction as each drug per se. The RqF treatment also caused a slower progression of the renal disease compared with F alone. The combination treatment seems to afford better BP control and appears to be a favourable therapeutic option in patients with renal disease and hypertension.

Objective To evaluate the effect of advanced glycation end-products (AGEs) and the inhibitor of their formation, aminoguanidine, on tumor necrosis factor-α (TNFα) production (as a functional marker) by rat peritoneal macrophages (PMΦ). Design Charles River rats underwent a daily intraperitoneal injection of peritoneal dialysis solution [(PDS), 4.25 g/dL dextrose; Dialine, Travenol, Ashdod, Israel] for a 2-month period (group E). Another group of rats was subjected to the same protocol with the addition of 25 mg/kg aminoguanidine (group A). Three control groups were utilized: ( 1 ) rats that were injected daily with aminoguanidine only (group AO), ( 2 ) rats that were injected with Dulbecco's phosphate-buffered saline (group D), and ( 3 ) rats in which no intervention was carried out (group C). After 2 months, PMΦ were isolated from rat peritoneal effluent and their TNFα production measured by ELISA in cell-free culture supernatants, in both the basal state and after 24-hour stimulation with lipopolysaccharide (LPS). The concentrations of AGEs in peritoneal effluent were assayed and correlated to TNFα levels. PMΦ obtained from normal rats were then incubated for 24 hours with ( 1 ) the peritoneal effluent of each of the above respective groups, with or without LPS; ( 2 ) increasing concentrations of AGEs (0 - 250 μg/mL); and ( 3 ) increasing concentrations of aminoguanidine (0 - 7.5 mg/mL), and TNFα secretion again determined. Results After 2 months of daily intraperitoneal injection of PDS, in the basal state, TNFα production was significantly higher in PMΦ isolated from the peritoneal effluent groups (groups E, A, and AO) compared to controls (group C). Following LPS stimulation, a further increase in TNFα secretion was seen, with a significantly greater response in group AO versus groups E, A, and D. Effluent AGEs were markedly elevated only in group E. No correlation was found between TNFα secretion by these PMΦ and the concentration of AGEs. On incubation with the respective peritoneal effluents (groups E, A, and AO), in both the basal and stimulated state, TNFα production by PMΦ from normal rats was significantly enhanced compared to group C. Incubation with increasing concentrations of AGEs or aminoguanidine resulted in an increase of TNFα secretion by these PMΦ. Conclusions Following intermittent intraperitoneal administration of glucose-based PDS, rat PMΦ are chronically activated, as evidenced by increased basal TNFα secretion. The peritoneal effluent of such treated animals is capable of stimulating TNFα production by normal rat PMΦ. These data suggest that glucose-based PDS acts as a primer of PMΦ, which retain their ability to further stimulation by LPS. Although, in vitro, AGEs promote TNFα secretion by normal rat PMΦ, in vivo, their influence is probably modulated by other factors. Aminoguanidine has a specific inducing effect on rat PMΦ, independent of glucose-based PDS.

Objective Glucose-based dialysate induces non enzymatic glycation within the peritoneal cavity. To evaluate the relationship between the formation of advanced glycation end-products (AGEs) and peritoneal transfer for small solutes and macromolecules, we developed a model of simulated peritoneal dialysis (PD) in normal rats. Methods Male albino rats of the Charles River strain were divided into two sets of 3 groups (15 – 25 rats in each group). In the experimental (E) group, the rats were intra-peritoneally (IP) injected daily with a commercially available 4.25% dextrose solution. In the control puncture (CP) group, the peritoneum was punctured daily, but no PD solution infused. In an age-matched control (CC) group, no intervention was given. Two study protocols were used. Protocol A (duration 20 weeks) consisted of a daily IP injection of 10 mL PD solution per 100 g body weight. In protocol B, a double volume of PD solution was introduced (20 mL per 100 g body weight). At 9, 16, and 20 weeks in protocol A, and at 9 weeks in protocol B, urea, creatinine, microalbumin [(MAL) measured using specific anti-rat albumin monoclonal antibody], and AGEs (measured by fluorescent assay with excitation at 370 nm and emission at 440 nm) were measured in peritoneal effluent and serum. Results At no time during the study were AGEs detected in serum from any group in either protocol. In both protocols, no differences were found between the control groups (CP, CC) with respect to all parameters. In protocol A, the dialysate-to-plasma ratio (D/P) of urea was significantly higher in the experimental group as compared with the control groups at 9, 16, and 20 weeks [9 weeks: 0.59 ± 0.03 (E) vs 0.39 ± 0.02 (CP) vs 0.46 ± 0.02 (CC), p < 0.0004 and p < 0.002, respectively; 16 weeks: 0.71 ± 0.08 (E) vs 0.42 ± 0.01 (CP) vs 0.46 ± 0.01 (CC), p < 0.0001 and p < 0.02, respectively; 20 weeks: 0.57 ± 0.03 (E) vs 0.39 ± 0.01 (CP) vs 0.41 ± 0.02 (CC), p < 0.002 and p < 0.004, respectively]. At 16 and 20 weeks, dialysate MAL levels were significantly increased in group E [16 weeks: 354.00 ± 80.35 μg/mL (E) vs 134.75 ± 14.36 μg/mL (CP) vs 110.69 ± 7.83 μg/mL (CC), p < 0.04 and p < 0.03, respectively; 20 weeks: 283.17 ± 14.71 μg/mL (E) vs 105.14 ± 12.11 μg/mL (CP) vs 135.50 ± 19.03 μg/mL (CC), p < 0.00001 and p < 0.0001, respectively]. In protocol B, at completion of the study (week 9), D/P urea, effluent MAL, and AGEs were significantly higher in the experimental group as compared with the control groups [D/P: 0.67 ± 0.04 (E) vs 0.46 ± 0.07 (CP) vs 0.41 ± 0.02 (CC), p < 0.0002 and p < 00001, respectively; MAL: 336.8 ± 63.30 μg/mL (E) vs 125.71 ± 16.77 μg/mL (CP) vs 119.00 ± 39.75 μg/mL (CC), p < 0.008 and p < 0.007, respectively; AGEs: 265.77 ± 33.49 U/mg creatinine (E) vs 163.10 ± 21.99 U/mg creatinine (CP) vs 83.17 ± 22.66 U/mg creatinine (CC), p < 0.02 and p < 0.001, respectively]. Peritoneal effluent AGEs were found to be significantly correlated with D/P urea and dialysate MAL ( r = 0.42, p < 0.04, and r = 0.7, p = 0.00001, respectively). Conclusions In situ generation of AGEs constitutes the chief origin of peritoneal AGEs. Advanced glycation end-products affect peritoneal permselectivity for both small and large solutes. The rat model of simulated peritoneal dialysis developed in this experiment provides a reliable method for studying peritoneal AGE formation and effect on peritoneal transfer of small solutes and macro-molecules.

Abstract —We previously found that chronic exogenous hyperinsulinemia without sugar supplementation does not elevate blood pressure. This may be partially explained by the ability of insulin to release nitric oxide and cause vasodilatation. To test this hypothesis, we studied 4 groups of rats: 9 rats (body weight, 213±14 g) treated with a gradual increase of a sustained-release subcutaneous insulin pellet; 9 rats (body weight, 213±9 g) treated with N G -nitro- l -arginine methyl ester (L-NAME) in drinking water 50 mg/L; 19 rats (body weight, 217±11 g) treated with the combination of L-NAME and insulin; and 9 control rats (body weight, 218±11 g). Blood pressure was followed weekly for 6 weeks, and then rats were studied in metabolic cages. Weight gain was not different during the 6 weeks. Renal function did not differ between the 4 groups, but 24-hour urinary nitrite/nitrate excretion was lower ( P P P P l -arginine 2 g/L abrogated the effects of L-NAME and insulin combination. In conclusion, chronic exogenous hyperinsulinemia does not affect blood pressure but may cause hypertension when endothelial function is compromised.

Background. Pregnant rats with adriamycin nephropathy (ADRP rats) develop hypertension and have an increased vascular reactivity to noradrenaline in the isolated mesenteric bed in vitro. We have shown previ- Introduction ously that the administration of daltroban, a specific thromboxane receptor antagonist, prevented hyperten- Hypertension in pregnancy is associated with increased sion in ADRP rats. vascular reactivity, compared with the decreased vascuMethods. We measured the eVect of daltroban (10’5 lar resistance observed during normal pregnancy [1]. mol/l ) on the vasoconstrictory response to noradrena- The clinical picture of pre-eclampsia displays many line (1‐10 mmol/l ) in the isolated mesenteric bed of functional features of endothelial disease [2]. Recent ADRP rats at the end of pregnancy, as compared with studies have shown that blood pressure increased in normal pregnant and adriamycin-treated virgin rats. pregnant rats with early adriamycin nephropathy In further experiments, we measured the changes of (ADRP rats). This was accompanied by a worsening flow induced by increasing concentrations of the of proteinuria and a relative decrease of glomerular thromboxane analogue, U46619 (10’7‐10’6 mol/ l) . filtration rate (GFR) [3]. The development of hyperFinally, changes of flow were assessed in arteries tension in pregnancy, in contrast with the decrease of maximally constricted with U46619 (10’6 mol/ l), blood pressure occurring during pregnancy in other during perfusion in the presence of increasing concen- hypertensive rat models [4‐8], rendered this a specific trations of daltroban (10’7‐10’5 mol/ l). model and prompted us to look for possible mechanResults. Daltroban diminished the response to nor- isms of deranged vascular behaviour. In previous adrenaline in all groups, shifting the concentration- works, it has been demonstrated that hypertension is eVect curve to the right. However, at maximal concen- completely prevented by treatment with a thromboxane trations of noradrenaline, daltroban was ineVective in receptor antagonist [9]. Subsequently it has been all rats, except in ADRP animals. The vasoconstrictory shown that in ADRP rats, the vascular reactivity of response to U46619 was significantly reduced in all isolated perfused mesenteric beds to noradrenaline was pregnant rats, both normal and adriamycin-treated. not decreased as expected during normal pregnancy Daltroban progressively released the vasoconstriction [10]. In the present study, we have evaluated the induced by U46619 in all groups. However, this vaso- possible role played by thromboxane in the altered dilator response was attenuated in the adriamycin- response of the isolated mesenteric vasculature of treated rats, the slopes of their curves being smaller ADRP rats to the vasoconstrictive action of than those of the respective untreated groups noradrenaline. (0.038±0.006 in virgin rats vs 0.063±0.011 in controls, P

Haemodialyzed (HD) patients have been found to have an increased bile cholesterol level and an increased saturation index in bile. These changes were markedly enhanced in the presence of a low-protein diet. To evaluate whether such changes influence the prevalence of cholelithiasis in patients with end-stage renal failure, real-time sonography was performed to detect the presence of gallstones (GS) in 54 HD (28 males, 26 females, mean age 52.4 ± 15.4 years) and 39 continuous ambulatory peritoneal dialysis (CAPD; 22 males, 17 females, mean age 59.1 ± 14.9 years) patients. No patient had diabetes. The patients’ charts were reviewed for the following data: age, sex, primary renal disease, obesity (20% above ideal weight), history suggestive of gallbladder disease or previous cholecystectomy, duration of dialysis, and serum cholesterol levels. Overall, cholelithiasis was documented in 12 of 93 (12.9%) patients, 7 HD and 5 CAPD. When comparing the factors outlined above, no significant difference was found between HD and CAPD patient groups, either with or without cholelithiasis. Gallbladder disease was asymptomatic in all except 1 patient who required cholecystectomy. Using a healthy control group consisting of local age- and sex-matched inhabitants, GS were found in 8 of 134 (6%) of them (p > 0.05). We conclude that the prevalence rate of GS in our dialysis population (HD and CAPD) is similar to that of a local general population following a western-style diet, irrespective of dialysis mode.

Abstract Hypertensive complications are relatively common in pregnancy, particularly in the presence of preexisting renal disease. Although the pathogenesis of such complications is still unknown, recent animal studies have suggested that it may be related to impaired synthesis of nitric oxide (NO). Rats with adriamycin nephropathy develop a “preeclamptic-type” pregnant state characterized by elevated blood pressure, lack of hyperfiltration, and enhanced proteinuria. Preliminary studies with this model have implicated inadequate NO synthesis in the development of preeclamptic-like pregnancy. The aim of the present study was to confirm this hypothesis. Pregnant rats, both normal (PREG) and those with adriamycin nephropathy (AN-PREG), received 100 mg/L N ω -nitro- l -arginine methyl ester PO from the middle of gestation to term (day 11, term approximately 22 days). One group of AN-PREG rats received either l -arginine or d -arginine (2 g/L) from midpregnancy. At term, systolic pressure, mean arterial pressure, urinary metabolites of NO, creatinine clearance, and urinary protein were assessed. At term, compared with virgin rats with adriamycin nephropathy, untreated AN-PREG rats had increased systolic pressure, mean arterial pressure, and proteinuria (mean arterial pressure, 124±2.5 versus 99.7±1.6 mm Hg [ P P P =NS). In PREG rats, urinary metabolites of NO increased approximately threefold at term pregnancy compared with control. By contrast, in AN-PREG rats, excretion of urinary metabolites of NO increased only by approximately 1.7-fold ( P N ω -nitro- l -arginine methyl ester enhanced blood pressure and decreased creatinine clearance but did not influence proteinuria. Excretion of urinary metabolites of NO was similarly inhibited in all rats. In AN-PREG rats, l -arginine normalized blood pressure (91±2.15 mm Hg) and lowered proteinuria partially but significantly. d -Arginine had no effect. In summary, AN-PREG rats are unable to adequately increase NO synthesis when physiologically required. Correction of this deficit by l -arginine treatment induced a significant clinical improvement.

Normal pregnancy is characterized by a marked reduction in peripheral vascular resistance. Blood pressure is diminished, while cardiac output, blood volume, renal blood flow and the glomerular filtration rate are increased. These hemodynamic changes are reversed in preeclampsia-eclampsia (PE-E), a condition considered to be related to a dysfunction of the endothelium. Decreases in the production of nitric oxide (NO) and prostacyclin (in association with an increased synthesis of thromboxane A2) may play a role in the pathogenesis of PE-E. Recent reports have supported the concept that an imbalance between vasodilators and vasoconstrictors may explain the clinical, laboratory and hemodynamic disturbances observed in PE-E. Particular attention has been given to the fact that a state of L-arginine NO deficiency may be present. The control of hypertension, rest, and close clinical and laboratory surveillance remain the gold standard to minimize the severity of the complications of PE-E. However, on the basis of its physiology and pathophys-iology, low-dose aspirin has been recommended in pregnancies at risk to prevent or, at least, to delay the occurrence of PE-E. Although initial reports showed promising results, recent conclusions from large trials have moderated this optimism. The use of supplemental L-arginine may be considered another possibility of treatment, and experimental data have given convincing results, but there are no reports on PE-E. Therefore, the practical management of PE-E requires prudence, careful follow-up and prompt decisions on the precise moment for delivery (which remains the most effective therapeutic procedure).

The rat remnant kidney, a popular model of experimental renal failure, has also been used to assess the histological bone changes associated with reduction in renal mass. The suitability of this model has been challenged, especially with regard to the standardization of animals from different age groups and various degrees of renal failure. The present study was undertaken: (1) to better evaluate the histomorphometric changes associated with reduction in renal mass ; (2) to assess these changes over a longer follow-up period as compared to those of matched intact animals ; (3) to define the response to pharmacological doses of calcitriol. Male rats were evaluated 4 and 8 weeks after induction of renal failure (5/6 nephrectomy) and compared with age-matched control rats with intact kidneys. Plasma biochemistry, creatinine clearance and parathyroid hormone (PTH ) were obtained from normal rats and from the rats with chronic renal insufficiency. Histomorphometric studies were performed in all animals on the right tibial bone. Induction of renal failure of 4 weeks' duration (short-term study, age 16 weeks) was associated with increased PTH and bone resorption, but suppressed bone formation. At long-term follow-up (rats aged 20 weeks), the suppression in bone formation was even more prominent. These changes were assessed considering normal bone histomorphometry during the process of growing. Calcitriol administration was associated with a significant suppression of bone resorption and a spectacular increase in all osteoid parameters. The bone formation rate, however, remained in the same low range as that in untreated animals. This model of renal osteodystrophy is similar to human secondary hyperparathyroidism with regard to the enhanced bone resorption, but differs by the marked decrease in bone formation. There was a remarkable similarity between the response of rats with renal failure and that of patients with severe secondary hyperparathyroidism to large doses of calcitriol, leading in both to adynamic bone disease. Keeping in mind the species differences, the bone changes developing in the uraemic rats may be useful in understanding certain aspects of human renal osteodystrophy.

Treatment with beta-blockers affects oxygen metabolism and lipolysis during physical exertion. Together with possible central nervous system effects, this may impair the work capacity of treated hypertensive subjects. In a study of 1619 male employees, aged 45-64 years, mean resting and ambulatory heart rate (HR) and complaints of fatigue were compared between hypertensive workers treated with beta-blockers and untreated hypertensives and normotensives under low and high workload conditions. Treated hypertensives had lower mean resting HRs compared with normotensives and untreated hypertensives. Their change from resting to ambulatory HR during low and high workload was also lower than normotensives and untreated hypertensives, and they had higher fatigue scores than their untreated counterparts at both workload levels. The highest fatigue score was reported by treated subjects under high workload. These findings demonstrate a reduced HR response to physical work accompanied by more symptoms of fatigue during treatment with beta-blockers. When hypertensives are engaged in physically demanding work, other classes of antihypertensive therapy should be considered.

Background: Diabetes mellitus (DM) is one of the leading causes of chronic vascular disease, which can accelerate the development of cardiovascular and renal disorders. Vascular smooth muscle cells (VSMC) are involved in the occurrence of vascular atherosclerosis and arteriosclerosis. Calcitriol might inhibit endothelial proliferation, blunt angiogenesis, and serve as a cardioprotective agent. We evaluated the impact of a diabetic-like environment and calcitriol on VSMC gene and protein expression. Methods: VSMC were treated for 24 hours using 200 μg/ml AGE-HSA, 250 mg/dl glucose and 10-9 or 10-10 mol/l calcitriol. Microarray gene chip analysis, real time PCR, western blot and ELISA techniques were used to determine gene and protein expression. Results: A total of 2,693 genes were differentially expressed in a diabetic-like environment compared to control, with 1796 up-regulated and 897 down-regulated. These genes are responsible for functions involved in the regulation of metabolic processes, apoptosis and cell adhesion. Addition of calcitriol at physiological concentrations (10-10 mol/l) revealed 1,157 differentially expressed genes, with 673 up-regulated and 484 down-regulated. These genes significantly enriched functions such as regulation of small GTPase and RAS protein signal transduction, cell growth and extracellular matrix part. TXNIP, OPG, RANKL, KLF4, RANK and NFκB p50/p65 mRNA and protein expressions were further investigated. Conclusion: High throughput approach might lead to a better understanding of the pathways involved in the biological adaptation of VSMC exposed to diabetic-like conditions and eventually the possible beneficial effects of calcitriol treatment, which might delay the development of DM-related vascular complications.

The necessity of withdrawal of aspirin [acetylsalicylic acid (ASA)] for fear of perioperative or postoperative bleeding in patients about to undergo surgery is as yet controversial. In this study we prospectively evaluated the effect of ASA on postoperative bleeding in end-stage renal failure patients who underwent insertion, removal, and/or replacement of a peritoneal dialysis (PD) catheter at our institution from November 1999 to March 2001. During the study period 52 of the above procedures were consecutively performed in 46 patients. Patients whose catheters were removed as a result of refractory peritonitis were excluded from the study. In all cases the PD catheter used was the coiled two-cuff Tenckhoff (NIPRO™, Manchester, GA) catheter and the surgery was performed in the operating room under local anesthesia. No drains were left in the operating wound. Postoperative bleeding (wound hematoma or persistent oozing from the incision or exit site) was classified as either minor (requiring no professional intervention and/or blood replacement) or major [necessitating blood transfusion (≥1 unit red blood cells). Of the 52 procedures 29 (in 24 patients) were performed while the patient was receiving aspirin at the time of operation (aspirin group). The remaining 23 were without aspirin and constituted the control group. ASA dose was 100 mg/day in all but three who were on buffered ASA (325 mg/day). The groups were well matched with regard to age; sex; mean residual renal function; and preoperative international normalized ratio, activated partial thromboplastin time, and platelet count. In no case was there significant intraoperative bleeding. There were five (17.2%) and three (13.0%) minor bleeds in the aspirin group and control group, respectively. One major bleed occurred in the control group ending in an exploratory laparotomy. Of the nine bleeding complications six were observed after catheter removal. From these data we conclude that PD catheter insertion/removal can be safely performed under conventional low-dose aspirin therapy.

Peritoneal dialysis (PD) is one of the established methods for the management of patients with end-stage renal failure. Laparoscopy has been used to assist in the insertion of new catheters as well as for the salvage of malfunctioning peritoneal dialysis catheters (PDC).The purpose of this retrospective study was to review our experience in the utilization of laparoscopy for the management of PDC.We reviewed the charts of all consecutive patients who had undergone either a ap-assisted insertion of a PDC utilizing a modified peritoneoscopic Y-TEC [Medigroup, Inc, Oswego, Ill) technique (YT) under direct laparoscopic vision or laparoscopic-assisted procedures for the salvage of a malfunctioning PD catheter.Twenty nine patients had undergone 43 procedures that included the insertion of a new PD catheter using the modified YT technique, YT with simultaneous adhesiolysis and omentectomy; YT with repair of an epigastric hernia, omentectomy, adhesiolysis and repositioning of PDC; and ravage and repositioning of the obstructed PD catheter in all patients who needed repositioning of the catheter, the PDC was fixed with an intraperitoneal suture to the lower anterior abdominal wall. Postoperatively, malfunction of the catheter was found in one patient due to reclotting of PDC caused by oozing as a result of extensive adhesiolysis. One patient needed emergent laparotomy due to small bowel perforation that was missed during a difficult laparoscopic adhesiolysis.Laparoscopic surgery may be helpfuL for the diagnosis and the management of a malfunctioning PDC. A modified YT technique is safe and may be one of the alternative methods for the placement of a PDC.

Epidemiological studies have found that intrauterine growth retardation (IUGR) is closely related to hypertension and is associated with a reduced number of nephrons that may be a predisposing factor for the development of hypertension.To determine whether blood pressure levels of children with a history of IUGR are higher than those of children without IUGR.Diastolic, systolic and mean arterial blood pressure levels were measured in 64 children aged 8-12 years old with a history of IUGR (mean birth weight 1780 +/- 422 g) and compared with 64 age and gender-matched controls who had a normal birth weight (mean 3134 +/- 594 g).Contrary to previous reports, systolic blood pressure values were significantly lower in the IUGR group compared to the controls (91.6 +/- 11.3 vs. 96.6 +/- 13.9, P = 0.027). There was no difference in diastolic blood pressure values. In the IUGR group, systolic blood pressure correlated significantly with current weight (P0.01) and body mass index (P0.05), and diastolic blood pressure with weight gain between age 2 and 4 years (P0.05). None of the blood pressure values correlated with birth weight.Children born with IUGR have lower systolic blood pressure levels than matched controls at age 8-12 years. These data indicate that postnatal weight gain in this group has a greater impact on systolic blood pressure than birth weight.

Objective: The influence of pregnancy (P) on the evolution of primary renal disease is still controversial. In rats with early adriamycin nephropathy (ADR), pregnancy enhanced mean arterial pressure (MAP) and urine protein excretion (UP). It has been suggested that the development of hypertension in pregnancy may be related to a decreased synthesis of vasodilatory substance(s) by endothelial cells. In the present study, the effect of L-arginine, a precursor of the endothelium-derived relaxing factor nitric oxide (NO), was evaluated.Methods: Four groups of rats were studied (n = 10 each): 1—normal pregnancy (NP); 2-normal pregnancy treated with L-arginine (NP + LA); 3-ADR pregnant rats (ADRP); and 4-ADR pregnant rats treated with L-arginine (ADRP-1-LA). L-arginine, 2 g/1, was added to the drinking water from midpregnancy.Results: In ADRP rats, MAP increased to 135 ± 4.1 mm Hg, significantly above the values of 91 ± 1.2 mm Hg found in NP rats, P

BACKGROUND. High blood and tissue concentrations of glucose and advanced glycation end-products (AGEs) are thought to play an important role in the development of vascular diabetic complications. Therefore, the impact of extracellular AGEs and different glucose concentrations was evaluated by studying the gene expressions and the underlying cellular pathways involved in the development of inflammatory pro-atherosclerotic processes observed in cultured endothelial cells. METHODS. Fresh human umbilical vein cord endothelial cells (HUVEC) were treated in the presence of elevated extracellular glucose concentrations (5.5-28 mmol/l) with and without AGE-human serum albumin (HSA). Affymetrix GeneChip(R) Human Gene 1.0 ST arrays were used for gene expression analysis (total 20 chips). Genes of interest were further validated using real-time PCR and western blot techniques. RESULTS. Microarray analysis revealed significant changes in some gene expressions in the presence of the different stimuli, suggesting that different pathways are involved. Six genes were selected for validation as follows: thioredoxin-interacting protein (TXNIP), thioredoxin (TXN), nuclear factor of kappa B (NF-kappaB), interleukin 6 (IL6), interleukin 8 (IL8) and receptor of advanced glycation end-products (RAGE). Interestingly, it was found that the association of AGEs together with the highest pathophysiological concentration of glucose (28 mmol/l) diminished the expression of these specific genes, excluding TXN. CONCLUSIONS. In the present model that mimics a diabetic environment, the relatively short-term experimental conditions used showed an unexpected blunting action of AGEs in the presence of the highest glucose concentration (28 mmol/l). The interactive cellular pathways involved in these processes should be further investigated.

An increasing body of experimental data suggests a role for 24,25(OH)2D3 in bone metabolism. The present study was carried out to assess a possible therapeutic role of this vitamin D metabolite in renal osteodystrophy. Twenty-two chronic dialysis patients, most of whom were previously maintained on 1 alpha (OH)D3 therapy, received additional treatment with 10 micrograms/day 24,25(OH)2D3 and were compared to 19 patients receiving 1 alpha (OH)D3 alone. Analysis of transiliac bone biopsies obtained at study entry and following 10-16 months of treatment revealed that the combined therapy produced a decrease in bone turnover. Specifically, the addition of 24,25(OH)2D3 inhibited an increase in trabecular bone volume (BV/TV) and suppressed osteoclastic parameters. Thus BV/TV increased from 26.2 +/- 8.6 to 32.1 +/- 7.5% (p0.01) in the 1 alpha (OH)D3 group, but it remained unchanged in the combined therapy group. In contrast, the eroded surface (ES/BS), the osteoclast surface (Oc.S/BS), and the osteoclast numbers were significantly suppressed in patients receiving both 24,25(OH)2D3 and 1 alpha (OH)D3, as compared with those receiving 1 alpha (OH)D3 alone (p0.01, p0.01, and p0.001, respectively). These improvements were independent of changes in 1 alpha (OH)D3 dosage. The extent of bone aluminium deposits was unrelated to the administration of 24,25(OH)2D3 or to its effect. 24,25(OH)2D3 therapy was not associated with any adverse effects.

Parathyroid hormone (PTH), which is elevated in patients with chronic renal failure, has been shown to participate in the development of vascular calcification. Previous studies have demonstrated that PTH may promote endothelial expressions of proinflammatory parameters. On the basis of these data, we evaluated whether PTH may have an impact on endothelial osteoprotegerin (OPG), a vascular-protective factor which may control vascular calcification. Endothelial cells were stimulated with 10−12to 10−10mol/l PTH. PKC and PKA are the main cellular pathways of PTH. Inhibitors and activators of PKC or PKA were used to determine whether these signaling pathways are involved in the control of endothelial OPG. PTH induced a decrease in OPG secretion and mRNA expression. Treatment of PTH-stimulated cells by calphostin C (PKC inhibitor) induced a further decrease in OPG secretion, while Rp-cAMP (PKA inhibitor) had no additional effect. In nonstimulated cells, a PKC activator significantly stimulated OPG secretion, while a PKA activator was associated with a decline. These effects were blunted in the presence of calphostin C and Rp-cAMP, respectively. An increase in OPG secretion induced by a PKC activator indicates that the basal OPG secretion is mediated through PKC. The decrease induced by a PKA activator, which is similar to the decrease observed with PTH, suggests that the action of PTH on OPG secretion and mRNA expression may be due to the PKA pathway.

The life expectancy of dialysis patients depends, to a large extent, on blood access which provides uninterrupted and efficient treatment. Dialysis access created by a direct anastomosis between artery and vein usually allows normal dialysis for many years. Blood access by a bridge graft between artery and vein functions for a much shorter time and occludes chiefly because of endothelial hyperplasia at the graft vein anastomosis. This type of fistula is created when the veins of the patient are small. During the last few years the dialysis population is increasingly composed of adult and elderly patients suffering from diabetes mellitus, hypertension, dyslipidemias and atheromatous vascular disease so that a relatively large proportion of dialysis accesses are created using a bridge graft. Since we currently do not have the knowledge of how to arrest or delay the processes which lead to access occlusion, attempts are made to implement prophylactic strategies, find stenoses and dilate them before the access fails. Up to date, controlled trials have not succeeded in proving that this method prolongs access use. These trials did not describe the use of stents following dilatation.Between July 2002 and May 2005, 238 angiographies were performed on blood accesses including 179 angioplasties of stenoses. In sixteen patients a stent was deployed during the angioplasty.In ten patients dialysis was performed using the same access up to the end of the study period, an average of 43 months from the creation of the access. Three patients died with a functioning access and in three the access occluded during the period of followup.This study shows that the use of stents following angioplasty of dialysis access stenoses can improve the duration of use of accesses created through grafts.

Advanced glycation end products (AGEs), which are elevated in diabetic and uremic patients, may induce vascular dysfunctions, and calcitriol may improve the cardiovascular complications. Therefore, we examined whether calcitriol may modify the endothelial response to AGEs stimulation. Knowing the importance of nuclear factor-kappaB in endothelial inflammatory responses, the effect of AGEs and calcitriol on this pathway was also studied. Calcitriol was added to endothelial cells previously incubated with AGE-human serum albumin (HSA). AGE-HSA induced a decrease in endothelial nitric oxide synthase (eNOS) mRNA expression and enzyme activity. Addition of calcitriol to AGE-HSA-treated endothelial cells improved the decreased action of AGEs on the eNOS system. AGE-HSA increased the AGEs receptor mRNA and protein, which were both blunted by calcitriol. The parallel elevation of interleukin-6 mRNA in the presence of AGE-HSA was also blunted by calcitriol. The NF-kappaB-p65 DNA binding activity was enhanced and associated with a decrease in inhibitor kappaBalpha (IkappaBalpha) and an increase in phosphorylated (p)-IkappaBalpha levels. Addition of calcitriol blunted the AGEs-induced elevation of NF-kappaB-p65 DNA binding activity, a phenomenon related to an increased expression of IkappaBalpha. This increase was correlated to declined p-IkappaBalpha levels. The present results support the concept that calcitriol may act as a vascular protective agent counteracting the probable deleterious actions of AGEs on endothelial cell activities.

Hypercalcemie nephropathy: Chronic disease with predominant medullary inner stripe injury. Because of the recently observed augmentation of medullary hypoxic injury by calcium in isolated perfused rat kidneys (Kidney Int 34:186–194, 1988), renal morphology of chronic, prolonged hypercalcemia was investigated in vivo. Rats were treated with repeated injections of vitamin D2 (400,000 units/week) for two to eight weeks. Chronic elevation of plasma calcium from 2.1 to 2.8 mmol/liter (P < 0.001) was associated by a fall in maximal urine osmolality with no change in glomerular filtration rate. The most significant morphological alterations occurred in the inner stripe of the outer medulla; these changes were characterized by a sequence of active injury with subsequent destruction and atrophy of the medullary thick ascending limbs, fibroblastic and lymphocytic infiltration, and secondary dilatation of collecting ducts. Similar changes occurred in the medullary rays. These alterations were accompanied by increased renal prostanoid production and a predisposition to acute kidney failure from indomethacin. Because of its selective occurrence in zones of poorest oxygen supply, this inner stripe injury may derive from vulnerability to hypoxia and may play a role in some chronic nephropathies.

Captopril stimulates glomerular prostaglandin (PG) synthesis and increases glomerular filtration rate (GFR) in Na-repleted rats, whereas, in Na-depleted rats, it fails to stimulate PG synthesis and decreases GFR. In the present work the influence of chronic and acute NaCl loading on PG synthesis and renal function was studied in Na-depleted rats receiving captopril (LNC rats). Glomerular PGE2 and 6-keto-PGF1 alpha were not increased in LNC rats and were significantly lower than in Na-depleted rats (LN). Na repletion, while continuing captopril, increased PG synthesis above control levels. Addition of captopril in vitro to the incubation medium stimulated PGE2 synthesis in glomeruli of control rats, whereas it depressed it in LN rats. Acute loading with NaCl in LNC rats increased inulin and PAH clearances to values significantly greater than in control rats and similar to those of normal rats receiving captopril. Comparable volume loading with isotonic mannitol or 3% albumin increased inulin and PAH clearances only to control values. The specific effect of NaCl in acute loading was prevented by cyclooxygenase inhibition and was not mediated by increased systemic blood pressure. The results provide evidence that the effects of captopril on glomerular PG synthesis and renal function depend on the state of Na balance.

Halofuginone is a novel antifibrotic agent that can reverse the fibrotic process by specific inhibition of collagen type I synthesis.To evaluate the effect of Halo on the development of glomerulosclerosis and interstitial fibrosis in the 5/6 nephrectomy rat modelMale Wistar rats were assigned to undergo 5/6 NX or sham operation, and then divided into three groups: 5/6 NX rats (NX-Halo and NX-Control) and sham. Systolic blood pressure, proteinuria and body weight were determined every 2 weeks. At sacrifice (10 weeks) creatinine clearance was evaluated and remnant kidneys removed for histologic examination, sirius red staining and in situ hybridizationSystolic blood pressure increased progressively in both 5/6 NX groups. Halo slowed the increase in proteinuria in 5/6 NX rats. As expected, creatinine clearance was lower in 5/6 NX groups when compared to sham rats. Creatinine clearance was significantly higher in the NX-Halo group at the end of the study period. Histologic examination by light microscopy showed significantly less severe interstitial fibrosis and glomerulosclerosis in Halo-treated rats. The increase in collagen alpha1 (I) gene expression and collagen staining after nephrectomy was almost completely abolished by Halo.Halofuginone reduced proteinuria as well as the severity of interstitial fibrosis and glomerulosclerosis in 5/6 NX rats. The renal beneficial effect of Halo was also demonstrated by the blunted decrease in creatinine clearance observed in the treated animals.

A 41-year-old male patient in end-stage renal failure presented on two occasions, over an 18-month period, with painless unilateral visual deterioration and optic disc edema. Clinical findings were compatible with a diagnosis of uremic optic neuropathy. On his initial presentation, the patient refused the onset of dialysis, resulting in a permanent visual deficit of the left eye. On his subsequent admission with a similar clinical picture, this time of the right eye, dialysis combined with corticosteroid therapy was promptly instituted. This led to a rapid improvement of the visual acuity and visual field defects of the right eye concomitant with subsidence of the edema of the optic nerve head.

Parathyroid hormone (PTH), the major systemic calcium-regulating hormone, has been linked to uremic vascular changes. Considering the possible deleterious action of PTH on vascular structures, it seemed logical to evaluate the impact of PTH on the receptor of advanced glycation end products (RAGE) and interleukin 6 (IL-6) mRNA and protein expression, taking into account that such parameters might be involved in the pathogenesis of vascular calcification, atherosclerosis, and/or arteriolosclerosis. Human umbilical vein cord endothelial cells (HUVEC) were stimulated for 24 h with 10−12–10−10mol/l PTH. The mRNA expression of RAGE and IL-6 was established by reverse transcriptase/PCR techniques. RAGE protein levels were determined by Western blot and IL-6 secretion was measured by ELISA. The pathways by which PTH may have an effect on HUVEC functions were evaluated. PTH (10−11–10−10mol/l) significantly increased RAGE mRNA and protein expression. PTH also significantly increased IL-6 mRNA expression without changes at protein levels. The addition of protein kinase (PKC or PKA) inhibitors or nitric oxide (NO) synthase inhibitors significantly reduced the RAGE and IL-6 mRNA expression and the RAGE protein expression. PTH stimulates the mRNA expressions of RAGE and IL-6 and the protein expression of RAGE. These stimulatory effects are probably through PKC and PKA pathways and are also NO dependent. Such data may explain the possible impact of PTH on the atherosclerotic and arteriosclerotic progression.

It is estimated that by 2025,1.5 billion adults worldwide will be hypertensive. Early identification of the population at risk would lead to improved utilization of preventive measures. We aimed to evaluate whether baseline body mass index (BMI) and blood-pressure (BP) values during adolescence (categorized according to the guidelines of the European Society of Hypertension-European Society of Cardiology) are of use in predicting the development of hypertension in young adulthood.The study population consisted of 18,513 male regular army personnel who were initially recruited at 16.5 and 19 years of age between 1976 and 1996. The main outcome was the percentage of subjects who developed hypertension (or =140 systolic andor =90 diastolic) at ages 26 to 45 years.At baseline, BP categories were: optimal, 5961 (32.2%); normal, 7998 (43.2%); and high normal, 4554 (24.6%). Moreover, 1377 (7.4%) were overweight (BMI 25-30 kg/m(2)), and 199 (1.1%) were obese (BMI30 kg/m(2)). At follow-up, 2277 (12.3%) subjects developed hypertension. The percentages progressing to hypertension were 9.46%, 11.99%, and 16.56% for optimal, normal, and high-normal categories, respectively (P.01). Odds ratios (OR) for the development of hypertension in the normal and high-normal categories versus optimal were 1.30 (95% confidence interval [CI], 1.22-1.39) and 1.79 (95% CI, 1.67-1.93), respectively, adjusted for age and BMI. The ORs for hypertension in overweight and obese versus normal BMI were 1.75 (95% CI, 1.66-1.86) and 3.75 (95% CI, 3.45-4.07), adjusted for age and BP. Of 9762 remaining at ideal BMI at follow-up, the percentages progressing to hypertension were 5.3%, 6.4%, and 9.5% for optimal, normal, and high normal (at baseline) (P.01).The risk of developing hypertension in young adulthood may be predicted by BP categories and BMI at adolescence.

Advanced glycation end products, formed by the non-enzymatic glycation of proteins with reducing sugars, are thought to play a pathogenetic role in the vascular complications of diabetes, uremia and atherosclerosis. 132-microglobulin is a major constituent of amyloid fibrils in dialysis-related amyloidosis. AGE1-modified beta2m has been found in amyloid deposits of long-term hemodialysis patients. AGE-modified 132m has also been shown to enhance chemotaxis and increase tumor necrosis factor-alpha and interleukin-1 beta secretion by circulating and tissue monocytes/macrophages.To investigate the effect of AGE-modified 132m and AGE-human serum albumin on TNF-alpha and IL-1beta secretion by human peritoneal macrophages derived from patients on continuous ambulatory peritoneal dialysis.Human PMO were isolated from peritoneal dialysis effluent of stable CAPD patients and were incubated for 24 hours with AGE-modified beta2m, beta2m, AGE-HSA, HSA or lipopolysaccharide. TNF-alpha or IL-1beta secretion was measured by enzyme-linked immunosorbent assay in cell-free culture supernatants.Both AGE-modified beta2m and AGE-HSA significantly increased TNF-alpha and IL-1beta secretion by human PMO in a dose-dependent manner (50-200 microg/ml). In contrast, beta2m or HSA had no such stimulatory effect on TNF-alpha secretion but had a small significant increase in IL-1beta secretion.AGE-modified beta2m promotes in vitro TNF-alpha and IL-13 secretion by human PMO of CAPD patients. Activation of these macrophages by AGE-modified beta2m may be a contributory factor to the morphologic changes and altered permeability of the peritoneal membrane in long-term CAPD.

Background. Tetrahydrobiopterin (BH4) is a key cofactor of nitric oxide (NO) synthase. Reduced BH4 levels may mediate endothelial NO synthase uncoupling, resulting in reduced NO synthesis and enhanced oxidative stress. In rats after 5/6 nephrectomy (Nx), administration of BH4 prevents the onset of hypertension, typically observed 10 days after Nx. This effect is associated with an increased synthesis of NO. The aim of the present study was to evaluate the effect of chronic BH4 therapy on blood pressure and renal morphology. Methods. During an 8 week period, five groups of rats were studied: untreated 5/6 Nx rats, BH4-treated Nx rats (BH4, 10 mg/kg body weight/day administered intraperitoneally), L-arginine treated Nx rats (LA, 130 mg/kg/day), diltiazem-treated Nx rats (DILT, 30 mg/kg/day) and sham-operated rats. Treatments were commenced 24 h after surgery. Systolic blood pressure values (SBP), 24 h proteinuria (UP) and creatinine clearance rate (CCR) were assessed before and at weeks 4 and 8 of the study period. Histological changes in the kidney were evaluated at the end of the study (week 8). Results. Compared with baseline, in Nx rats both SBP and UP increased significantly (112±1 to 136± 1.4 mmHg, P

Pregnancy-induced hypertension in rats with chronic exogenous hyperinsulinemia is associated with reduced urinary excretion of nitric oxide metabolites. We tested the hypothesis that there are perturbations of endothelial nitric oxide synthase in their kidneys. We studied three groups of rats: control pregnant rats (n = 6); pregnant rats with hyperinsulinemia by subcutaneous sustained-release insulin pellet (n = 5); and hyperinsulinemic pregnant rats treated with l-arginine 2 gL in drinking water (n = 5). By the end of pregnancy blood pressure was 78 +/- 12 mm Hg in controls, 119 +/- 15 mm Hg in hyperinsulinemic rats, and 77 +/- 8 mm Hg in l-arginine-treated hyperinsulinemic rats, p0.007. Serum creatinine was 0.4 mg/dl in controls, 0.6 mg/dl in hyperinsulinemic rats, and 0.5 mg/dl in l-arginine-treated rats, p0.05. Corresponding urinary excretion of nitric oxide metabolites was 2.1 +/- 0.5, 1.2 +/- 0.2, and 1.5 +/- 0.2 micromols/mg creatinine, p0.01. Expression of endothelial nitric oxide synthase protein in kidneys by Western blot was not different between controls and hyperinsulinemic rats, 5.6 +/- 2.4 and 5.8 +/- 3.4 OD x mm2, but was nearly doubled in l-arginine-treated rats, 10.8 +/- 2.3, p0.03. Thus, the salutary effect of l-arginine on hyperinsulinemic pregnancy-induced hypertension (PIH) may be mediated, in part, by endothelial nitric oxide synthase in their kidneys.

Henoch-Schonlein purpura (HSP) is a systemic vasculitic disorder involving both arterioles and capillaries. Although mainly a disease of early childhood, it can occur at any age. HSP is typically recognized as a syndrome with four major components: rash, joint manifestations, abdominal symptoms and renal disease. It is usually a mild condition with a tendency to relapses and generally has a good prognosis. Occasionally, however, it takes on an aggressive course. Gastrointestinal involvement is potentially the most serious complication of HSP. It may mimic an abdominal emergency and in its severest form result in small bowel infarction and/or perforation. Renal manifestations range from asymptomatic haematuria and/or proteinuria through a nephrotic syndrome to progressive glomerulonephritis leading to end stage renal failure. Apart from the major components outlined above, HSP may affect almost every other bodily organ. Vasculitis involving the myocard, lungs (pulmonary haemorrhage), ureter (stenosing ureteritis) and nervous system have been reported. We describe a case of HSP in a 50 year old woman which was complicated by the development of necrotizing crescentic glomerulonephritis and a left hemiparesis due to cerebral vasculitis. Interestingly, this patient had first appeared at the age of 9 years with a nephrotic syndrome and had been diagnosed by renal biopsy at the age of 31 as IgA nephropathy (IgAN). On her current admission, steroid and immunosuppressive therapy resulted in an improvement of renal function and an almost complete disappearance of her neurologic deficit.