Cardioprotective Effect of Angiotensin II Receptor Antagonist on Perfused Ischemic Reperfusion Injury of Whole Isolated Rat Hearts

Objectives Investigated the eardioproteetive and mechanisms of losartan on whole isolated isehemie reperfused rat heart. Methods Langendorff perfused systems was used to investigate losartan effect on whole isolated rat hearts in CPK, LDH, MDA, SOD, ang Ⅱ and arrhythmia. Resuits Losartan decreased incidence of arrhythmia,improved atrial ventrieular block recovery in reperfusion period, during isehemie period, CPK and LDH in I/R group increased significantly compared with control group, 51.33±27.02 vs 22.42±13.33, 31.80±4. 56 vs 22.28±15.96, respectively, but greatly decreased in losartan group compared with I/R group,23.90±21.74 vs 51.33±27.02 and 11.50±13.20vs 31.80±4.56, respectively. During reperfusion period CPK, LDH increased significantly in I/R group compared with control group, 49.11 ±20.63 vs 12.14±5.92 and 28.70±4.69 vs 23.10±21.38, respectively, but decreased greatly in losartan group compared with I/R group, 39.40±9.60 vs 49. 11±20.63 and 14.50±13.75 vs 28.70±4.69. The content of MDA, ang II in I/R group myoeytes is higher than control group's , 26.± 9. 25 vs 17.2 ±3.37 and 8.43 ±3.81 vs 4.80±0.20. However the content of SOD in two groups has no significantly change, 148.20±8.72 vs 145.08±6.82. the content of MDA in losartan group myocardial tissue is much lower than control group, 15.92±4. 05 vs26.80±9.25 and the content of ang Ⅱ in losartan group myocardial tissue is much higher than I/R group, 12.44±6. 09 vs 8.43±3.21. The department of cardiology of second hospital of Tianjin medical university Tianjin 300211 However, SOD has no significant change in two groups, 143.47±7.91 vs145.08±6.82. Conclusions Losartan against isehemie-reperfusion injury of whole isolated rat hearts, those beneficial effects are mediate primarily by the inhibited of angiotensin Ⅱ binding with its receptor and inhibited oxygen free radical scavenging potential.