[Myocardial protective effect of acetylcholine against ischemia/reperfusion injury and its underlying mechanism].
OBJECTIVE
To determine whether the caidioprotection of acetylcholine (ACh) against ischeniia/reperftision (I/R) injury is re-kited to mitochondrial permeability transition pore (MEW) and mitochondrial AW-sensitive potassium channel (mitoK(ATP)).


METHODS
Male Sprague-Dawley rats were used for Langendorif isolated bean perkision. The hearts were subjected to global ischemia for 30 mm followed by 120 rein of reperfusion and the left ventricular hemodynaniic parameters were measured. Formazan, a product of 2,3, 5-triphenyl-tetrazolium chloride (TTC), which is proportional to myocardial viability, was measured at 490 nm, and the level of lactate dehydrogenase (LDH) in the coronary effluent was measured to evaluate the cardiac injury.


RESULTS
The pretreatment with ACh (0.1 mol/L, 5 mm) before I/R markedly increased myocardial formazan content, reduced LDH release, improved the recovery of the left veritficular developed pressure, +/- dP/dtmax, and rate pressure product (left ventricular developed pressure multiplied by hean rate) and attenuated the decrease of coronary flow during reperfusion. The opener of MPTP, atiractyloside (20 mmoL/L) or the inhibitor of mitoK(ATP), 5-hydroxydecanoate (100 micromol/L) abolisbed the beneficial effect of ACh.


CONCLUSIONS
In the isolated rat bean, ACh protects myocardium against ischemia/reperfusion injury via inhibiting the opening of MPTP and increasing the opening of mitoKATP in heart.
Sun
Guo-quan
GQ
Department of Physiology, Zhejiang Medical College, Hangzhou 310053, China.
Cui
Jie
J
Ye
Zhi-guo
ZG
Qian
Lin-bo
LB
Wang
Hui-ping
HP
Xia
Qiang
Q
D000109:Acetylcholine / Q000494:pharmacology*; D000818:Animals; D002316:Cardiotonic Agents / Q000494:pharmacology; D066298:In Vitro Techniques; D019194:Ischemic Preconditioning / Q000379:methods*; D008297:Male; D033681:Mitochondrial Membrane Transport Proteins / Q000187:drug effects* / Q000378:metabolism; D000083162:Mitochondrial Permeability Transition Pore; D017202:Myocardial Ischemia / Q000503:physiopathology; D015428:Myocardial Reperfusion Injury / Q000517:prevention & control*; D015221:Potassium Channels / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley
D002316:Cardiotonic Agents; D033681:Mitochondrial Membrane Transport Proteins; D000083162:Mitochondrial Permeability Transition Pore; D015221:Potassium Channels; C117780:mitochondrial K(ATP) channel; D000109:Acetylcholine