Angiotensin-mediated increase in renal sympathetic nerve discharge within the PVN: role of nitric oxide

• DOI: 10.1152/ajpregu.00338.2004
• Publication Date: 2005-12-02T01:34:37Z
• Authors: Yi-Fan Li; Wei Wang; William G. Mayhan; Kaushik P. Patel
• Keywords: Sympathetic nervous system

The paraventricular nucleus (PVN) of the hypothalamus is known to be an important site integration in central nervous system for sympathetic outflow. ANG II and nitric oxide (NO) play role regulation nerve activity. purpose present study was examine how interaction between NO within PVN affects outflow rats. Renal discharge (RSND), arterial blood pressure (AP), heart rate (HR) were measured response administration N G -monomethyl-l-arginine (L-NMMA) into PVN. Microinjection (0.05, 0.5, 1.0 nmol) increased RSND, AP, HR a dose-dependent manner, resulting increases 53 ± 9%, 19 3 mmHg, 32 12 beats/min from baseline, respectively, at highest dose. These responses significantly enhanced by prior microinjection L-NMMA blocked losartan, type 1 receptor antagonist. Similarly, antisense neuronal synthase also potentiated responses. Conversely, overexpression NOS with adenoviral gene transfer attenuated Push-pull (1 induced increase release. Our data indicate that receptors mediate excitatory effect on HR. PVN, which can stimulation, turn inhibits II-mediated This negative-feedback mechanism may maintaining overall balance tone