The effect of proctolin analogues and other peptides on locust oviduct muscle contractions.

The locust oviduct bioassay system was used to assess the ability of a variety of peptides to induce oviductal contractions. Proctolin analogues were three orders of magnitude less potent than proctolin. Proctolin supra-analogue and Arg-Tyr-Leu-Ala-Thr demonstrated high activity.