Fig. 6.

Effects of the monoamine transport inhibitor, cocaine, on dose–response curves for tryptamine-induced vasoconstriction of rat isolated perfused mesentery. Dose–response curves in the absence (□) and presence (■) of cocaine (10 μM, n = 4) and, in separate experiments (B.), in the additional presence (♦) of l-NAME (100 μM, n = 4). All points in A. significantly different between tryptamine alone and with cocaine, P < 0.05. In B. * Significantly different from tryptamine alone, P < 0.05, ** P < 0.01, *** P < 0.001. Each response is the mean ± S.E.M. increase in perfusion pressure.