Centrally induced vasodepressor and sympathetic nerve responses to taurine.

The effects of taurine on central cardiovascular regulation were investigated by intracerebroventricular (ICV) injection of taurine in urethane-anesthetized rats. Blood pressure fell gradually to attain the maximum level at 10 to 15 min after the injection of 50 micrograms taurine and returned to the basal level 20 min later. After injecting 200 micrograms of taurine, blood pressure began to fall within 30 seconds and attained the maximum level at 2 to 5 min and did not return to the basal level by 20 min. Both heart rate and abdominal sympathetic nerve activity decreased as the blood pressure fell, However, the similar amount of taurine injected intravenously did not affect the blood pressure, the heart rate or the abdominal sympathetic nerve activity. These results suggest that taurine causes the central nervous system to lower the blood pressure by decreasing the sympathetic nerve outflow.