The interaction between renin-angiotensin system and sympathetic nervous system in the peripheral vasculature of normal Sprague-Dawley rats

Authors : Mohammed H ABDULLA, , Munavvar A SATTAR, Nor A ABDULLAH

Pages : 521-527

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Publication Date : 2011-12-01

Article Type : Research Paper

Abstract :To evaluate possible interactions between the renin-angiotensin system insert ignore into journalissuearticles values(RAS); and the sympathetic nervous system insert ignore into journalissuearticles values(SNS); in the systemic circulation upon the intravenous administration of angiotensin II and a set of adrenergic agonists in normal Sprague-Dawley insert ignore into journalissuearticles values(SD); rats. Rats were treated with carvedilol, a non-selective b- and selective a1-adrenoceptor blocker, in a dose of insert ignore into journalissuearticles values(5 mg/kg); orally for 7 days, and on day 8, the animals were pentobarbitone-anaesthetized and prepared for systemic hemodynamic study. Dose-response relationships in terms of elevation in the magnitude of the mean arterial blood pressure in response to intravenous injection of noradrenaline insert ignore into journalissuearticles values(NA);, phenylephrine insert ignore into journalissuearticles values(PE);, methoxamine insert ignore into journalissuearticles values(ME);, and angiotensin II insert ignore into journalissuearticles values(Ang II); were determined. Data, mean ± S.E.M., were subjected to ANOVA with significance at P < 0.05. Carvedilol blunted the peripheral vascular response to NA, PE, ME, and Ang II insert ignore into journalissuearticles values(all P < 0.05);. It is concluded that peripheral vasoconstriction induced by Ang II is contributed to by adrenergic action. Furthermore, there is a cross-talk relationship between RAS and SNS in determining the responsiveness of the peripheral vasculature to adrenergic agonists and angiotensin II in normal rats.
Keywords : Key words Carvedilol, methoxamine, angiotensin II, Sprague Dawley rats