Glycine Protection Against Myocardial Ischemic Injury And Its Mechanism

Objective: Glycine is a simplest amino acid, which is not only an anti-endotoxin agent but also a kind of effective cell protectant. It has been demonstrated that glycine attenuates myocardial injury induced by endotoxin. The aim of the present study was to investigate the effect of glycine on myocardial ischemic injury. Method: Mice was fed with 20% glycine (0.25mL/10g, ig), 40% injection salviae miltiorrhizae composita (ISMC 0.25mL/10g, ig) or 0.25mL/10g (ig) distilled water twice a day. 7 days later O.OlmL/lOg 20% pituitrin or normal saline was injected intraperitoneally. The ECG was recorded and activities of NOS, SOD, MDA in the myocardium were examined. At the same time , the expression of heat shock protein 70 mRNA in the myocardium was also determined by RT-PCR. Result: Pretreatment with glycine inhibited J spot elevation induced by ischemia in ECG (P<0.01), Glycine increased activities of NOS, SOD and decreased the production of MDA in the myocardium (P<0.01), Glycine enhanced the expression of HSP 70 mRNA in the ischemia myocardium (P<0.01).Conclusion: The results suggest that pretreatment with glycine attenuates myocardial ischemic injury induced by pituitrin . The mechanism may be related to increases in activities of NOS and SOD, HSP70 mRNA expression in the myocardium and decrease in MDA.