[Effect of interleukin-2 on intracellular calcium transients in rat ventricular myocytes].
In the present study, we investigated the effect of interleukin-2 (IL-2) on the intracellular calcium in enzymatically isolated ventricular myocytes with the use of the spectrofluorometric techniques. It was shown that IL-2 (2.5  200 U/ml) depressed electrically induced   Ca(2+)  (i) transients of ventricular myocytes in a dose  dependent manner. IL-2 (200 U/ml) did not alter the caffeine  releasable pool of Ca(2+). Pretreatment with the non  selective opioid antagonist naloxone (10(-8)mol/L) or a specific kappa opioid antagonist nor  binaltorphimine (nor-BNI, 10(-8) mol/L) abolished the inhibitory effect of IL-2 (200 U/ml) on the   Ca(2+)  (i) transients of cardiomyocytes, whereas the specific delta opioid antagonist naltrindole (10(-6) mol/L) did not abolish the inhibitory effect. The effect of IL-2 (200 U/ml) was also abolished after pretreatment with pertussis toxin (PTX, 5 mg/L) as well as phospholipase C (PLC) inhibitor U73122 (5  10(-6) mol/L), but not by tyrosine kinase inhibitor genistein (10(-4) mol/L). It is concluded that the depressant effect of IL-2 on the   Ca(2+)  (i) transients of isolated ventricular myocytes is mainly mediated by cardiac kappa opioid receptor pathway including a PTX sensitive Gi-protein and PLC, but not by tyrosine kinase.
Cao
C M
CM
Department of Physiology, Zhejiang University School of Medicine, Hangzhou 310031, China. xiaqiang@cmm.zju.edu.cn
Xia
Q
Q
Ye
Z G
ZG
Zhang
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X
D000818:Animals; D002118:Calcium / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D019204:GTP-Binding Proteins / Q000378:metabolism; D006352:Heart Ventricles / Q000378:metabolism; D066298:In Vitro Techniques; D007376:Interleukin-2 / Q000494:pharmacology*; D032383:Myocytes, Cardiac / Q000187:drug effects / Q000378:metabolism*; D051381:Rats; D017473:Receptors, Opioid, kappa / Q000502:physiology
D007376:Interleukin-2; D017473:Receptors, Opioid, kappa; D019204:GTP-Binding Proteins; D002118:Calcium