Logo do repositório
 

Catalase blockade reduces the pressor response to central cholinergic activation

Carregando...
Imagem de Miniatura

Orientador

Coorientador

Pós-graduação

Curso de graduação

Título da Revista

ISSN da Revista

Título de Volume

Editor

Tipo

Artigo

Direito de acesso

Resumo

Intracerebroventricular (icv) injection of hydrogen peroxide (H2O2), a reactive oxygen species, or the blockade of catalase (enzyme that degrades H2O2 into H2O and O2) with icv injection of 3-amino-1,2,4-triazole (ATZ) reduces the pressor effects of angiotensin II also injected icv. In the present study, we investigated the effects of ATZ injected icv or intravenously (iv) on the pressor responses induced by icv injections of the cholinergic agonist carbachol, which similar to angiotensin II induces pressor responses that depend on sympathoexcitation and vasopressin release. In addition, the effects of H2O2 icv on the pressor responses to icv carbachol were also tested to compare with the effects of ATZ. Normotensive non-anesthetized male Holtzman rats (280–300 g, n = 8–9/group) with stainless steel cannulas implanted in the lateral ventricle were used. Previous injection of ATZ (5 nmol/1 μl) or H2O2 (5 μmol/1 μl) icv similarly reduced the pressor responses induced by carbachol (4 nmol/1 μl) injected icv (13 ± 4 and 12 ± 4 mmHg, respectively, vs. vehicle + carbachol: 30 ± 5 mmHg). ATZ (3.6 mmol/kg of body weight) injected iv also reduced icv carbachol-induced pressor responses (21 ± 2 mmHg). ATZ icv or iv and H2O2 icv injected alone produced no effect on baseline arterial pressure. The treatments also produced no significant change of heart rate. The results show that ATZ icv or iv reduced the pressor responses to icv carbachol, suggesting that endogenous H2O2 acting centrally inhibits the pressor mechanisms (sympathoactivation and/or vasopressin release) activated by central cholinergic stimulation.

Descrição

Palavras-chave

Blood pressure, Catalase inhibitor, Cholinergic activation, H2O2, Hypertension, Reactive oxygen species

Idioma

Inglês

Citação

Brain Research Bulletin, v. 153, p. 266-272.

Itens relacionados

Financiadores

Unidades

Unidade
Faculdade de Odontologia
FOAR
Campus: Araraquara


Cursos de graduação

Programas de pós-graduação