The paraventricular nucleus (PVN) of the hypothalamus is known to be involved in the control of sympathetic outflow. The goal of the present study was to examine the influence of endogenous GABA input into the PVN on renal sympathetic nerve discharge (RSND) during heart failure (HF). In urethane-anesthetized rats, bicuculline, a GABA antagonist, microinjected in the PVN produced a dose-dependent increase in RSND in control and HF rats, ['here was an attenuation in the increase of RSND due to bicuculline in HF compared to control rats. Dose (nmole) 0.5 L2 10 Control (n=7) 1.5±0.4 2.5±0.6 3.8±1.1 Heart Failure (n=7) 0.5±0.1 1.1±0.3 1.7±0.4 Values represent mean change in integrated RSND (mV) ±SEM. represents p<0.05 vs. control. These data suggest that the endogenous GABAminergic input into the PVN of HF rats is less effective in suppressing RSND compared to control rats. We conclude that a reduced GABA-mediated inhibition in the PVN ma) be responsible for the increased sympathetic outflow in rats with HF.
|Original language||English (US)|
|Publication status||Published - Dec 1 1996|
ASJC Scopus subject areas
- Molecular Biology