2004 Volume 95 Issue 3 Pages 390-393
The effect of captopril on neurally evoked bradycardia and tachycardia was investigated in pithed rats. Captopril enhanced the vagal nerve stimulation-evoked bradycardia. Angiotensin I reduced the vagal bradycardia, which was reversed by subsequent administration of captopril. Bradykinin did not affect the neurally evoked bradycardia. Captopril and angiotensin I affected neither the exogenous acetylcholine-evoked bradycardia nor the sympathetic nerve stimulation-evoked tachycardia. These results suggest that the interruption of angiotensin II formation by captopril causes less presynaptic inhibition of acetylcholine release via angiotensin II receptors without affecting cardiac sympathetic neurotransmission.