Discrepancy between central sympathoinhibitory action and peripheral hemodynamic effects of pindolol in anesthetized rats.

The present study was carried out to elucidate the relationship between changes in central sympathetic nerve activity and the peripheral hemodynamic effects of pindolol in anesthetized rats. Intravenous pindolol (0.1 mg/kg) produced a decrease in cardiac sympathetic nerve activity without a significant change in heart rate. Renal sympathetic nerve activity was also decreased by pindolol (0.1 and 0.5 mg/kg, i.v.) dose-dependently, but changes in mean arterial pressure were not dose-related. In addition, pindolol (0.1 and 0.5 mg/kg, i.v.) produced a dose-dependent reduction of preganglionic splanchnic nerve activity. These findings suggest that pindolol possesses a central sympathoinhibitory action, but there is a discrepancy between this central effect and peripheral cardiovascular effects of pindolol in rats.