Figure 3.

(a) Contractile and relaxant effects of human U-II in rat isolated mesenteric artery. Data above zero indicate the contractile effects of the peptide in resting arteries, whilst the data below zero denote the relaxant effects of human U-II in methoxamine-precontracted vessels. Where appropriate, data were fitted to the logistic equation and the parameters are given in the text. (b) Original experimental record showing the relaxant effect of human U-II in rat isolated mesenteric artery precontracted with methoxamine (10 μM). Vertical lines denote addition of drugs at the concentrations indicated.