Fig. 3.

Effects of phospholipase and COX inhibitors on dose–response curves for tryptamine-induced vasoconstriction of rat isolated perfused mesentery. Dose–response curves in the absence (□) and presence (■) of A. phospholipase C inhibitor, U73,122 (10 μM, n = 4), B. phospholipase A₂ inhibitor, PACOCF₃ (10 μM, n = 3), C. COX-1/COX-2 inhibitor, indomethacin (10 μM, n = 5), and D. COX-2 inhibitor, nimesulide (10 μM, n = 3). * Significantly different points from tryptamine alone, P < 0.05, ** P < 0.01. Each response is the mean ± S.E.M. increase in perfusion pressure.