Evidence for postsynaptic effect of captopril in isolated perfused rabbit kidney

The influence of captopril (SQ 14225) on the vascular and norepinephrine-releasing responses to nerve stimulation (2, 5 and 10 Hz) was assessed in isolated blood-free perfused rabbit kidney. At a concentration of 0.23 and 0.46 mM in the perfusion medium, captopril markedly attenuated the vasoconstrictor response but did not influence the release of norepinephrine produced by nerve stimulation. These results suggest that captopril may act as an alpha-antagonist at a postjunctional level.