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1. Interaction between paraventricular nucleus and septal area in the control of physiological responses induced by angiotensin II

Author

L.A.A. Camargo, W.A. Saad, S. Simões, T.A.B. Santos, and W. Abrão Saad

Subjects
AT1 receptors, AT2 receptors, Water, Sodium, Paraventricular nucleus, Medial septal area, Medicine (General), R5-920, Biology (General), QH301-705.5
Abstract

We determined the effects of losartan (40 nmol) and PD 123319 (40 nmol) (both non-peptides and selective antagonists of the AT1 and AT2 angiotensin receptors, respectively), and [Sar¹, Ala8] angiotensin II (ANG II) (40 nmol) (a non-selective peptide antagonist of angiotensin receptors) injected into the paraventricular nucleus (PVN) on the water and salt appetite, diuresis and natriuresis and mean arterial pressure (MAP) induced by administration of 10 nmol of ANG II into the medial septal area (MSA) of male Holtzman rats weighing 250-300 g. The volume of drug solution injected was 0.5 µl over a period of 10-15 s. The responses were measured over a period of 120 min. ANG II alone injected into the MSA induced an increase in all the above parameters (8.1 ± 1.2, 1.8 ± 0.3, and 17.1 ± 1.0 ml, 217 ± 25 µEq/120 min, and 24 ± 4 mmHg, respectively, N = 10-12) compared with vehicle-treated rats (1.4 ± 0.2, 0.6 ± 0.1, and 9.3 ± 0.5 ml, 47 ± 5 µEq/120 min, and 4.1 ± 0.8 mmHg, respectively, N = 10-14). Pretreatment with losartan and [Sar¹, Ala8] ANG II completely abolished the water and sodium intake, and the pressor increase (0.5 ± 0.2, 1.1 ± 0.2, 0.5 ± 0.2, and 0.8 ± 0.2 ml, and 1.2 ± 3.9, 31 ± 4.6 mmHg, respectively, N = 9-12), whereas losartan blunted the urinary and sodium excretion induced by ANG II (13.9 ± 1.0 ml and 187 ± 10 µEq/120 min, respectively, N = 9). Pretreatment with PD 123319 and [Sar¹, Ala8] ANG II blocked the urinary and sodium excretion (10.7 ± 0.8, 9.8 ± 0.7 ml, and 67 ± 13 and 57 ± 17 µEq/120 min, respectively, N = 9), whereas pretreatment with PD 123319 partially blocked the water and sodium intake, and the MAP induced by ANG II administration (2.3 ± 0.3, 1.1 ± 0.1 ml, and 12 ± 3 mmHg, respectively, N = 9-10). These results suggest the angiotensinergic effect of the MSA on the AT1 and AT2 receptors of the PVN in terms of water and sodium homeostasis and MAP modulation.

Published
2002
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2. Effect of injection of L-NAME on drinking response

Author

W.A. Saad, L.A.A. Camargo, R. Saad, A.F. Pereira, and S. Simões

Subjects
nitric oxide, water intake, SFO, dehydration, CNS, Medicine (General), R5-920, Biology (General), QH301-705.5
Abstract

The drinking behavior responses to centrally administered NG-nitro-L-arginine methyl ester (L-NAME; 10, 20 or 40 µg/µl), an inhibitor of nitric oxide synthase, were studied in satiated rats, with cannulae stereotaxically implanted into the lateral ventricle (LV) and subfornical organ (SFO). Water intake increased in all animals after angiotensin II (ANG II) injection into the LV, with values of 14.2 ± 1.4 ml/h. After injection of L-NAME at doses of 10, 20 or 40 µg/µl into the SFO before injection of ANG II (12 ng/µl) into the LV, water intake decreased progressively and reached basal levels after treatment with 0.15 M NaCl and with the highest dose of L-NAME (i.e., 40 µg). The water intake obtained after 40 µg/µl L-NAME was 0.8 ± 0.01 ml/h. Also, the injection of L-NAME, 10, 20 or 40 µg/µl, into the LV progressively reduced the water intake induced by hypertonic saline, with values of 5.3 ± 0.8, 3.2 ± 0.8 and 0.7 ± 0.01 ml/h, respectively. These results indicate that nitric oxide is involved in the regulation of drinking behavior induced by centrally administered ANG II and cellular dehydration and that the nitric oxide of the SFO plays an important role in this regulation.

Published
1999
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3. Functional evidence that the central renin-angiotensin system plays a role in the pressor response induced by central injection of carbachol

Author

W.A. Saad, A.C. Luiz, L.A.A. Camargo, J.E.N. Silveira, S. Fóglia, J.V. Menani, and William A. Saad

Subjects
pressor response, central angiotensin, carbachol, Medicine (General), R5-920, Biology (General), QH301-705.5
Abstract

We investigated the effects of losartan, an AT1-receptor blocker, and ramipril, a converting enzyme inhibitor, on the pressor response induced by angiotensin II (ANG II) and carbachol (a cholinergic receptor agonist). Male Holtzman rats (250-300 g) with a stainless steel cannula implanted into the lateral ventricle (LV) were used. The injection of losartan (50 nmol/1 µl) into the LV blocked the pressor response induced by ANG II (12 ng/1 µl) and carbachol (2 nmol/1 µl). After injection of ANG II and carbachol into the LV, mean arterial pressure (MAP) increased to 31 ± 1 and 28 ± 2 mmHg, respectively. Previous injection of losartan abolished the increase in MAP induced by ANG II and carbachol into the LV (2 ± 1 and 5 ± 2 mmHg, respectively). The injection of ramipril (12 ng/1 µl) prior to carbachol blocked the pressor effect of carbachol to 7 ± 3 mmHg. These results suggest an interaction between central cholinergic pathways and the angiotensinergic system in the regulation of arterial blood pressure

Published
1997
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4. Central Evidence That Neuronal Nitric Oxide and Muscarinic Receptor Influence the Salivary Secretion Induced by Pilocarpine

Author

W.A. Saad ., I.F.M.S Guarda ., L.A.A. Camargo ., and R.S. Guarda .

Subjects
medicine.medical_specialty, Chemistry, Muscarinic acetylcholine receptor M3, Cell Biology, Muscarinic acetylcholine receptor M1, Endocrinology, Salivary secretion, Neuronal nitric oxide, Pilocarpine, Internal medicine, Muscarinic acetylcholine receptor, medicine, Muscarinic acetylcholine receptor M4, Molecular Medicine, medicine.drug
Published
2005
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5. Influence of arginine vasopressin receptor and nitric oxide on the water, sodium intake and arterial blood pressure induce by angiotensin injected into third ventricle of the brain

Author

W.A. Saad ., I.F.M.S. Guarda ., L.A.D.A. Camargo ., R.S. Guarda ., T.A.F.B.D. Santos ., Universidade de Taubaté (UNITAU), Universidade Estadual Paulista (Unesp), and Universidade de São Paulo (USP)

Subjects
Angiotensin receptor, cannula, nitrergic nerve, Arginine, argipressin receptor, arginine, angiotensin II, chemistry.chemical_compound, rat, rat strain, article, ANGII AVP V 1 receptors, blood pressure regulation, Sodium appetite an blood pressure, fluid intake, pressor response, sodium chloride, cardiovascular system, Molecular Medicine, mean arterial pressure, CNS, hormones, hormone substitutes, and hormone antagonists, circulatory and respiratory physiology, sodium intake, medicine.medical_specialty, Mean arterial pressure, 7-Nitroindazole, water, animal experiment, Nitric oxide, NO, animal tissue, ANGII AVP V1 receptors, body weight, male, nitric oxide, Internal medicine, Renin–angiotensin system, inhibition kinetics, medicine, sodium appetite, Animalia, controlled study, brain third ventricle, 7 nitroindazole, nonhuman, Cell Biology, enzyme activation, angiotensin receptor, Angiotensin II, Endocrinology, Blood pressure, chemistry
Abstract

Made available in DSpace on 2019-09-12T16:26:07Z (GMT). No. of bitstreams: 0 Previous issue date: 2006 As several structures of the central nervous system are involved in the control of hydromineral and cardiovascular balance we investigated whether the natriorhexigenic and pressor response induced by the injection of ANG II into the 3rd V could be mediated by vasopressinergic and nitrergic system. Male Holtzman rats weighing 200-250 g with cannulae implanted into the 3rd V were used. The drugs were injected in 0.5 μL over 30-60 sec. Controls were injected with a similar volume of 0.15 M NaCl. ANGII increased the water intake vs control. AVPA injected into 3rd V prior to ANGII decreased the dipsogenic effect of ANGII. L-arginine also decreased the water intake induced by ANGII. AVPA plus L-arginine inhibit the water intake induced by ANGII. 7NIT injected prior to ANGII potentiated the dipsogenic effect of ANGII. Pre-treatment with ANGII increased the sodium ingestion vs control. AVPA decreased the ANGII effect in sodium intake. L-arginine also decreased the natriorhexigenic effect of ANGII. The combination of L-arginine and AVPA inhibit the sodium intake induced by ANGII. 7NIT injected prior to ANGII potentiated the sodium intake induced by ANGII. ANGII induced an increase in Mean Arterial Pressure (MAP) vs control. AVPA and L-arginine induced a decreased in the pressor effect of ANGII. The combination of L-arginine and AVPA inhibit the pressor effect of ANGII. 7NIT injected prior to ANGII into 3rd V potentiated the pressor effect of ANGII. These data suggest that arginine vasopressin V1 receptors and Nitric Oxide (NO) within the circumventricular structures may be involved in sodium intake and pressor response induced by the activation of ANGII receptors within the circumventricular neurons. These studies revealed the involvement of sodium appetite by utilizing the angiotensinergic, vasopressinergic and nitrergic system in the central regulation of blood pressure. © 2006 Asian Network for Scientific Information. Saad, W.A., Department of Exacts and Naturals Sciences, Uiara, Araraquara São Paulo, Brazil, Institute of Bioscience, UNITAU, Taubaté, SP, Brazil, Department of Physiology and Pathology, School of Dentistry, UNESP, 1680 Humaitá Street, Araraquara, SP 14801-903, Brazil, Department of Surgery, School of Medicine, University of São Paulo, São Paulo, Brazil Guarda, I.F.M.S., Public Medical Hospital, São Paulo, Brazil Camargo, L.A.D.A., Department of Physiology and Pathology, School of Dentistry, UNESP, 1680 Humaitá Street, Araraquara, SP 14801-903, Brazil Guarda, R.S., Department of Exacts and Naturals Sciences, Uiara, Araraquara São Paulo, Brazil Saad, W.A., Department of Exacts and Naturals Sciences, Uiara, Araraquara São Paulo, Brazil, Institute of Bioscience, UNITAU, Taubaté, SP, Brazil, Department of Physiology and Pathology, School of Dentistry, UNESP, 1680 Humaitá Street, Araraquara, SP 14801-903, Brazil, Department of Surgery, School of Medicine, University of São Paulo, São Paulo, Brazil Santos, T.A.F.B.D., Institute of Bioscience, UNITAU, Taubaté, SP, Brazil

Published
2006

8. Pediatric Liver Transplantation: Comparison Between Results From Deceased and Living Related Transplantation

Author

W.A. Saad, A.P. Bonanno, and M.A.F. Ribeiro

Subjects
Waiting time, Transplantation, Pediatrics, medicine.medical_specialty, business.industry, medicine.medical_treatment, Liver transplantation, Survival Analysis, Living donor, Tissue Donors, Liver Transplantation, Surgery, Treatment Outcome, El Niño, Cadaver, Living Donors, medicine, Humans, Survivors, Child, business, Dropout (neural networks), Medical literature
Abstract

Timely access to a living donor has reduced pretransplant mortality in pediatric liver transplantation. We hypothesized that this strategy may provide better posttransplant outcomes, due to shorter waiting times on the transplant list. A extensive search in the medical literature from the last 10 years showed clear evidence of the benefits of living donors, namely, decreased dropout rates as well as the chance to transplant the patients in better clinical situation. However, a negative impact was related to the higher morbidity rates when compared to whole grafts from deceased donors.

Published
2008
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11. Effect of intrahypothalamically injected parathion on food and water intake of normal and fasted rats

Author

W.A. Saad, L.A.A. Camargo, Y. Yashuda, and A.M. Cabral

Subjects
Pharmacology, Male, medicine.medical_specialty, Time Factors, Parathion, digestive, oral, and skin physiology, Ventral medial nucleus, Hypothalamus, Median Eminence, Drinking Behavior, Fasting, Feeding Behavior, Injections, Rats, chemistry.chemical_compound, Endocrinology, chemistry, Internal medicine, medicine, Ingestion, Animals, Water intake
Abstract

Summary The injection of parathion (0,0-diethyl 0-p-nitrophenyl thiophosphate) directly into the lateral hypothalamic area (L.H.A.) and ventral medial nucleus (V.M.N.) through chronically implanted cannulae determined alterations in the amount of food and water ingested by rats. There was an increased intake of water and a decreased ingestion of food following the injection of parathion into the L.H.A.; opposite effects were observed following the injection into the V.M.N.

Published
1975

12. Effect of intrahypothalamic injection of methylic parathion and metasystox on food and water intake of normal and fasted rats

Author

N. Morita, L.A.A. Camargo, Y. Yashuda, A.M. Cabral, and W.A. Saad

Subjects
Male, Food intake, medicine.medical_specialty, Insecticides, Time Factors, Ventral medial nucleus, Drinking, Hypothalamus, Methyl Parathion, Injections, chemistry.chemical_compound, Eating, Thalamus, Internal medicine, medicine, Animals, Water intake, Pharmacology, Parathion, digestive, oral, and skin physiology, Organothiophosphorus Compounds, Fasting, Rats, Endocrinology, chemistry
Abstract

Methylic parathion (0,0-dimethyl-0-p-nitrophenyl phosphothioate) and metasystox (0,0-dimethyl-0-ethyl-mercaptophenyl phosphothioate) directly injected into the lateral hypothalamic area (L.H.A.) and the ventral medial nucleus (V.M.N.) through permanently implanted cannulae caused alterations in the quantities of food and water ingested by rats. The injection of these organophosphorates into the L.H.A. caused an increase in water intake and a decrease in food intake; opposite effects were observed when the drugs were injected in the V.M.N.; moreover, the effects were also quantitatively different.

Published
1976

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