Influence of angiotensin II receptor subtypes of the paraventricular nucleus on the physiological responses induced by angiotensin II injection into the medial septal area
Objective - We determined the effects of losartan and PD 123319 (antagonists of the AT1 and AT2 angiotensin receptors, respectively), and [Sar1, Ala8] ANG II (a relatively peptide antagonist of angiotensin receptors) injected into the paraventricular nucleus (PVN) on water and 3% NaCl intake, and th...
| Autores: | , |
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| Tipo de recurso: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2003 |
| País: | Brasil |
| Institución: | Universidade Estadual Paulista (UNESP) |
| Repositorio: | Repositório Institucional da UNESP |
| Idioma: | inglés |
| OAI Identifier: | oai:repositorio.unesp.br:11449/67281 |
| Acceso en línea: | http://dx.doi.org/10.1590/S0066-782X2003000400004 http://hdl.handle.net/11449/67281 |
| Access Level: | acceso abierto |
| Palabra clave: | Blood pressure Central nervous system Sodium balance 1 (4 dimethylamino 3 methylbenzyl) 5 diphenylacetyl 4,5,6,7 tetrahydro 1h imidazo[4,5 c]pyridine 6 carboxylic acid angiotensin II bromethol losartan receptor subtype sodium chloride stainless steel angiotensin receptor antihypertensive agent imidazole derivative pyridine derivative saralasin sodium vasoconstrictor agent animal experiment animal model animal tissue arterial pressure attenuation blood pressure measurement body weight brain surgery cannula controlled study diuresis fluid intake male measurement natriuresis nonhuman rat septum pellucidum sodium excretion sodium intake thalamus midline nucleus urinary excretion animal anterior hypothalamus blood pressure drinking drug antagonism drug effect homeostasis metabolism Sprague Dawley rat Angiotensin II Animals Antihypertensive Agents Blood Pressure Diuresis Drinking Homeostasis Imidazoles Losartan Male Paraventricular Hypothalamic Nucleus Pyridines Rats Rats, Sprague-Dawley Receptors, Angiotensin Saralasin Septum of Brain Sodium Vasoconstrictor Agents |
| Sumario: | Objective - We determined the effects of losartan and PD 123319 (antagonists of the AT1 and AT2 angiotensin receptors, respectively), and [Sar1, Ala8] ANG II (a relatively peptide antagonist of angiotensin receptors) injected into the paraventricular nucleus (PVN) on water and 3% NaCl intake, and the diuretic, natriuretic, and pressor effects induced by administration of angiotensin II (ANG II) into the medial septal area (MSA) of conscious rats. Methods - Holtzman rats were used. Animals were anesthetized with tribromoethanol (20 mg) per 100 grams of body weight, ip. A stainless steel guide cannula was implanted into the MSA and PVN. All drugs were injected in 0.5-μl volumes for 10-15 seconds. Seven days after brain surgery, water and 3% NaCl intake, urine and sodium excretion, and arterial blood pressure were measured. Results - Losartan (40 nmol) and [Sar1, Ala8] ANG II (40 nmol) completely eliminated whereas PD 123319 (40 nmol) partially blocked the increase in water and sodium intake and the increase in arterial blood pressure induced by ANG II (10 nmol) injected into the MSA. The PVN administration of PD 123319 and [Sar1, Ala8] ANG II blocked whereas losartan attenuated the diuresis and natriuresis induced by MSA administration of ANG II. Conclusion - MSA involvement with PVN on water and sodium homeostasis and arterial pressure modulation utilizing ANGII receptors is suggested. |
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