The paraventricular nucleus (PVN) of the hypothalamus is known to be involved in the control of sympathetic outflow. Recently, sodium nitroprussîde (SNP) infusion into the PVN was shown to decrease arterial pressure. The goal of the present study was to examine the role of the nitric oxide (NO) system in the PVN on renal sympathetic nerve discharge (RSND). In urethane-anesthetized Sprague Dawley rats, L-NMMA, an NO synthase inhibitor, microinjected in the PVN produced a dose-dependent increase in RSND and SNP, an NO donor, produced a dose-dependent decrease in RSND. Dose (pmolel 50 100 200 L-NMMA (n=5) 0.6±0.2 l.0±2 1.7±0.3 Dose (nmole) 50 100 200 SNP(n=5) -0.5±0.3 -0.8±0.4 -l.l±0.3 Values represent mean change in RSND (mV) ±SEM. represents p<0.05 vs. baseline. These data suggest that the endogenous NO activity within the PVN is effective in depressing RSND. We conclude that an NO system within the PVN may be responsible for control of sympathetic outflow in rats. Supported by NIH grant HL48023.
|Original language||English (US)|
|State||Published - Dec 1 1996|
ASJC Scopus subject areas
- Molecular Biology