Effect of G(alphaq/11) protein and ATP-sensitive potassium channels on prostaglandin E(1) preconditioning in rat hearts.
OBJECTIVE
To investigate the effect of G(alphaq/11) signaling pathway and ATP-sensitive potassium channels (K(ATP) channels) on prostaglandin E1 (PGE1) induced early and delay-preconditioning protection in rat hearts.


METHODS
Two series of experiments were performed in Wistar rat hearts. In the first series of experiment, all rats were pretreated with PGE1 40 min or 23 h 20 min before the experiment. Ischemia-reperfusion injury was induced by 30 min coronary artery occlusion followed by 90 min reperfusion. Hemodynamics, infarct size, and scores of ventricular arrhythmias were measured. The expression of G(alphaq/11) protein in the heart was measured by Western blot analysis in the second series.


RESULTS
Preconditioning with PGE1 (25 microg/kg) markedly reduced infarct size, left ventricular end-diastolic pressure, and scores of ventricular arrhythmia. The effect of PGE1 was significantly attenuated by glibenclamide (1 mg/kg, ip), a nonselective K(ATP) channel inhibitor. PGE1 caused a significant increase in the expression of G(alphaq/11) protein.


CONCLUSIONS
Activations of G(alphaq/11) signal pathway and K(ATP) channel played significant roles in the cardioprotection of PGE1 preconditioning in rat heart and might be an important mechanism of signal transduction pathway during the PGE1 preconditioning.
Ma
Shou-guo
SG
Department of Cardiology, The 159th hospital of PLA, Zhumadian 463000, China.
Fu
Run-fang
RF
Feng
Guo-qing
GQ
Wang
Zhen-ji
ZJ
Ma
Xiang-qin
XQ
Weng
Shi-ai
SA
D000255:Adenosine Triphosphate / Q000502:physiology; D000527:Alprostadil / Q000494:pharmacology*; D000818:Animals; D043802:GTP-Binding Protein alpha Subunits, Gq-G11 / Q000378:metabolism*; D005905:Glyburide / Q000494:pharmacology; D019157:Ischemic Preconditioning, Myocardial; D008297:Male; D015428:Myocardial Reperfusion Injury / Q000209:etiology / Q000378:metabolism / Q000473:pathology; D026902:Potassium Channel Blockers / Q000494:pharmacology; D015221:Potassium Channels / Q000187:drug effects*; D051381:Rats; D017208:Rats, Wistar; D015398:Signal Transduction
D026902:Potassium Channel Blockers; D015221:Potassium Channels; D000255:Adenosine Triphosphate; D043802:GTP-Binding Protein alpha Subunits, Gq-G11; D000527:Alprostadil; D005905:Glyburide