Endothelin-1 may be a physiologic modulator of vasoconstriction in rat kidney

The effect of endothelin-1 (ET-1), in concentrations well below threshold and near physiologic levels, has been examined on vasoconstrictor responses to perivascular nerve stimulation and norepinephrine in rat isolated kidney, perfused through the renal artery with physiologic salt solution. A 60-min exposure to ET-1 (1, 10, and 100 pM) had little or no effect on the basal perfusion pressure but enhanced responses to nerve stimulation (4 Hz, 10-s train) by 123±12% (n=6), 125±8% (n=6), and 226±49% (n=7) of the control response, respectively. Responses to nerve stimulation were consistent in the absence of ET-1