The bradykinin receptor of the rat uterus affects the ligand properties of charged mercurials.

: Using monovalent organic mercurials to modify the response to the oxytocic action of bradykinin (BK) on the rat uterus, a charge effect, related to the reagent applied, was noted. With neutral, and positively charged mercurials, a bimodal pattern of activity, causing stimulation of BK contraction at lower, and inhibition at higher concentrations was observed. With negatively charged mercurials transient stimulation occurred, inhibition only appearing after very large doses and long periods of incubation. Anionic charges of the bradykinin receptor affect the ligand properties of mercurials, repelling negative charges. By themselves, mercurials did not cause any response.