心肌缺血大鼠血浆8-异前列腺素F2α水平及N-乙酰半胱氨酸干预作用

Significance of plasma 8-iso-prostaglandin F2alpha level in acute myocardial ischemia and intervention effect of N-acetylcysteine: a study in rats]

OBJECTIVE: To examine the correlation between 8-iso-prostaglandin F2alpha (8-iso-PGF2alpha) levels in the plasma and myocardial tissue of rats with myocardial ischemia and observe the intervention effect of N-acetylcysteine (NAC), for the purpose of assessing the value of 8-iso-PGF2alpha in estimating the extent of free radical damage and implementing possible interventions. METHODS: Forty-five Wistar rats were divided into ischemia, ischemia+NAC and control groups, and in the former 2 groups, acute myocardial ischemia models were produced by pituitrin. Elevated ST segment in ECG served as the indicator for myocardial ischemia. Rats in ischemia+NAC group were pre-treated with NAC (0.1 g/kg x d) for three weeks before the ischemia 8-iso-PGF2alpha levels in the plasma and myocardial tissue were determined by enzyme-linked immunosorbent assay (ELISA). RESULTS: In ischemia group, the 8-iso-PGF2alpha levels in the plasma and myocardial tissue were 187.4+/-45.8 pg/ml and 259.3+/-47.5 pg/g, respectively, higher than those in the control group (60.4+/-13.7 pg/ml and 88.6+/-16.9 pg/g, respectively, P<0.01) and those in ischemia+NAC group (88.2+/-16.4 pg/ml and 109.4+/-24.7 pg/g, respectively, P<0.01). A positive correlation was noted between the 8-iso-PGF2alpha levels in the plasma and myocardial tissue (r=0.865, P<0.01). In comparison with the control group, elevation of the ST segment of ECG in rats with myocardial ischemia was obvious, and the peak elevation occurred 45 min after ischemia (0.34+/-0.05 mV, P<0.01). Pre-treatment with NAC proved to help alleviate the subsequent ischemia, with ST segment elevation of only 0.18+/-0.05 mV. CONCLUSION: In condition of acute myocardial ischemia in rats, 8-iso-PGF2alpha levels tend to increase, which can be indicative of the degree of myocardial ischemia. NAC pre-treatment can alleviate the ischemic condition by offsetting the damage caused by the free radicals.