[Modification with bradykinin of membrane-bound lipid peroxidation and Ca2+-activity of the thymus and liver]

Effect of bradykinin on activity of Ca2+-ATPase and accumulation of malonic dialdehyde (MDA) was studied in proliferating and relatively non-proliferating (resting) cells of thymus and liver tissues. The peptide effect was studied in vivo and in vitro after intravenous administration into mice at a dose of 2 mg/kg or by means of addition of bradykinin (10(-6)M) to a suspension of calf thymocyte membranes. In vivo bradykinin caused the most distinct decrease in MDA accumulation and activation of Ca2+-ATPase in thymus as compared with liver tissue. In vitro incubation of thymocyte membranes with bradykinin led to prolongation of the latent period of MDA formation and to a distinct increase in the Ca2+-ATPase activity. Modification of these processes in membranes appear to be one of important functions of bradykinin in proliferation.