Interleukin 2 stimulates heart contractility in the presence of exogenous arachidonate or the calcium ionophore A 23187.
An increase in the isometric developed tension (IDT) of isolated rat atria was observed shortly after the addition of human interleukin 2 (IL-2) to the organ preparation with subthreshold concentrations of either arachidonate (AA, 1.98 X 10(-6)M) or the calcium ionophore A 23187 (1.9 X 10(-6)M). Both natural purified IL-2 (nIL-2) and yeast recombinant IL-2 (rIL-2) were active in this experimental system. It was determined that this lymphokine was active at 2 X 10(-11)M, considering as a reference the specific activity of rIL-2. Anti-IL-2 monoclonal antibody (anti-IL-2 MAb) abolished this reaction. Inhibition of atrial phospholipase C activity by nitrocarboxyphenyl N,N-diphenylcarbamate (NCDC, 5 X 10(-6)M) prevented the development of the inotropic positive effect of IL-2 in the presence of either AA or A 23187. The synthetic diacylglyceride 1-oleoyl, 2-acetyl-glycerol (OAG) replaced the IL-2 as stimulatory signal but NCDC had no effect on the reaction. The results suggest that IL-2 can alter the physiologic behaviour of the heart and that its mechanism of action is probably similar to the one proposed for other IL-2 targets (IL-2 receptor-positive T lymphocytes, T cell lines).
D000818:Animals; D016718:Arachidonic Acid; D001095:Arachidonic Acids / Q000494:pharmacology*; D016275:Atrial Function; D000001:Calcimycin / Q000494:pharmacology*; D006325:Heart Atria / Q000187:drug effects; D066298:In Vitro Techniques; D007376:Interleukin-2 / Q000494:pharmacology*; D009200:Myocardial Contraction / Q000187:drug effects*; D010716:Phosphatidylinositols / Q000378:metabolism; D011493:Protein Kinase C / Q000378:metabolism; D051381:Rats
D001095:Arachidonic Acids; D007376:Interleukin-2; D010716:Phosphatidylinositols; D016718:Arachidonic Acid; D000001:Calcimycin; D011493:Protein Kinase C