[Protective effects of SMT on myocardial ultrastructure of ischemia reperfusion injury in heart of rat].
OBJECTIVE
To Investigate the myocardial ultrastructure effects of SMT on the ischemia reperfusion injury (IRI) in the rat heart.


METHODS
Eighteen Spraqua-Dawley rats were randomly divided into three groups: ischemia reperfusion group (IR), subjected to 60 min of o-cclusion and 20 min of reperfusion of the anterior descending branch of left coronary artery; IR + SMT group (SMT), given the selective iNOS inhibitor S-methylisothiourea sulfate (SMT, 5 mg/kg, i.v.) before reperfusion; control group (C), didn't occlude coronary artery after exposing heart and observed 80 min. Electrocardiogram (ECG) was recorded. Nitrite and nitrate content were measured in myocardium and blood serum. The changes of myocardial ultrastructure were observed with electron microscope.


RESULTS
Ischemia reperfusion induced ST segment elevation and T waves inversion or tallness in ECG, damaged myocardial ultrastructure, increased nitrite and nitrate content in myocardium and blood serum after IR compared with before IR(P < 0.01). Administration of SMT improved the changes of ECG and the injury of myocardial ultrastructure. Nitrite and nitrate content of myocardium were lower than IR group (P < 0.05). The change of nitrite and nitrate level of blood serum in SMT group was nearly in C group.


CONCLUSIONS
SMT can prevent myocardium injury from reperfusion following ischemia.
Department of Physiology, Guangdong Medical College, Zhanjiang 524023.
H Z
HZ
Zheng
B
B
Cai
Y H
YH
Feng
H
H
Sun
K R
KR
Cai
D000818:Animals; D005260:Female; D007550:Isothiuronium / Q000031:analogs & derivatives / Q000494:pharmacology*; D008297:Male; D015428:Myocardial Reperfusion Injury / Q000188:drug therapy* / Q000473:pathology*; D009206:Myocardium / Q000648:ultrastructure*; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors; D051381:Rats; D017207:Rats, Sprague-Dawley
D007550:Isothiuronium; D019001:Nitric Oxide Synthase; C027744:S-methylisothiopseudouronium