Resumo

ISRAEL, A; SOSA-CANACHE, B  e  MEDINA, I. La Angiotensina II y la respuesta neurohumoral frente al estrés. AVFT [online]. 2005, vol.24, n.2, pp.3-8. ISSN 0798-0264.

Footshocks (FS) increases mean arterial pressure (MAP) and heart rate (HR). We tested the hypothesis that endogenous angiotensin II (ANG) supports sympathetically mediated pressor response to FS. Our results show that AT₁ receptor blockade with either losartan, valsartan or eprosartan blunted stress-response to FS. Reduction of circulating ANG induced by bilateral nephrectomy (NPHX), suppressed MAP increase and plasma catecholamines elevation observed after FS. Stress induced-pressor response to FS in nephrectomized rats was restored by the administration of a subpressor dose of synthetic ANG. Reduction of plasma ANG by high sodium diet suppressed, while increased ANG levels induced by low sodium diet facilitated stress-response to FS. Our results indicate that endogenous ANG supports sympathetic mediated stress-response, via stimulation of prejunctional AT₁ receptors.

Palavras-chave : Angiotensin II; Stress; Neurohumoral response.