Figure 4.

Effects of increasing concentrations of DrmNPF on leucokinin 1 (LK 1)-induced contractions of a single isolated Rhodnius prolixus hindgut. Closed arrows indicate addition of 10^-9 M LK 1 (left column) or various concentrations of DrmNPF and 10^-9 M LK 1 (right column). The addition of DrmNPF was always preceded by a trial of LK 1 alone (A–E). Open arrows indicate washing with physiological saline. The preparation was washed at 5 minute intervals for 20 minutes between applications of peptide solutions.