Nitric oxide and L-type calcium channel influences the changes in arterial blood pressure and heart rate induced by central angiotesin II

We study the voltage dependent calcium channels and nitric oxide involvement in angiotensin II-induced pressor effect. The antipressor action of L-Type calcium channel antagonist, nifedipine, has been studied when it was injected into the third ventricle prior to angiotensin II. The influence of nitric oxide on nifedipine antipressor action has also been studied by utilizing NW-nitro-L-arginine methyl ester (LNAME) (40 μg/0.2 μl) a nitric oxide synthase inhibitor and L-arginine (20 μg/0.2 μl), a nitric oxide donor agent. Adult male Holtzman rats weighting 200–250 g, with cannulae implanted into the third ventricle were injected with angiotensin II. Angiotensin II produced an elevation in mean arterial pressure and a decreased in heart rate. Such effects were potentiated by the prior injection of LNAME. L-arginine and nifedipine blocked the effects of angiotensin II. These data showed the involvement of L-Type calcium channel and a free radical gas nitric oxide in the central control of angiotensin II-induced pressor effect. This suggested that L-Type calcium channel of the circunventricular structures of central nervous system participated in both short and long term neuronal actions of ANG II with the influence of nitrergic system

Effect of nifedipine and L-arginine on heart rate induced by the injection of angiotensin II into the third ventricle

Number of animals at the top of each column. Data are means ± S.E.M. *< 0.05 vs.saline+saline, < 0.05 vs. saline+angiotensin II (Neuman-Keuls post-hoc test).<p><b>Copyright information:</b></p><p>Taken from "Nitric oxide and L-type calcium channel influences the changes in arterial blood pressure and heart rate induced by central angiotesin II"</p><p>Behavioral and Brain Functions : BBF 2008;4():22-22.</p><p>Published online 24 May 2008</p><p>PMCID:PMC2409355.</p><p></p

Effects of nifedipine and LNAME on the mean arterial pressure induced by the injection of angiotensin II into the third ventricle

Number of animals at the top of each column. Data are means ± S.E.M. *< 0.05 vs. saline+saline, < 0.05 vs. saline+angiotensin II and P < 0.05 vs. LNAME+angiotensin II (Neuman-Keuls post-hoc test).<p><b>Copyright information:</b></p><p>Taken from "Nitric oxide and L-type calcium channel influences the changes in arterial blood pressure and heart rate induced by central angiotesin II"</p><p>Behavioral and Brain Functions : BBF 2008;4():22-22.</p><p>Published online 24 May 2008</p><p>PMCID:PMC2409355.</p><p></p

Effects of nifedipine and LNAME on heart rate induced by the injection of angiotensin II into the third ventricle

Number of animals at the top of each column. Data are means ± S.E.M. *< 0.05 vs. saline+saline, < 0.05 vs. saline+angiotensin II and P < 0.05 vs. LNAME+angiotensin II (Neuman-Keuls post-hoc test).<p><b>Copyright information:</b></p><p>Taken from "Nitric oxide and L-type calcium channel influences the changes in arterial blood pressure and heart rate induced by central angiotesin II"</p><p>Behavioral and Brain Functions : BBF 2008;4():22-22.</p><p>Published online 24 May 2008</p><p>PMCID:PMC2409355.</p><p></p