Chakrabarty S, Thomas P, Sheridan D J
Academic Cardiology Unit, St Mary's Hospital Medical School, London, U.K.
Eur Heart J. 1991 May;12(5):583-9. doi: 10.1093/oxfordjournals.eurheartj.a059944.
The effects of alterations in platelet activity on arrhythmias, haemodynamics and extent of necrosis during coronary ligation for 30 min were assessed in rabbits. Reduction of platelet counts to less than 1% of control by intravenous injection of platelet antiserum (1 ml kg-1 i.v.) reduced the volume of necrosed tissue from 23 +/- 2% to 15 +/- 1%, P less than 0.01 (expressed as % of total LV) and attenuated the hypotensive effect of ischaemia. Pretreatment with the platelet activating factor (PAF) antagonist BN 52021 also attenuated the hypotension and necrosis caused by coronary ligation 23 +/- 2% vs 14 +/- 1%, P less than 0.01. Pretreatment with the thromboxane antagonist CGS 13080 attenuated the hypotensive response to ischaemia but had only a very small effect on the area of necrosis. Administration of PAF at 10 min following coronary ligation markedly increased the volume of necrosed tissue 36 +/- 2%, P less than 0.01 and caused VF and haemodynamic collapse in 10 out of 12 animals. Pretreatment with platelet antiserum or the PAF antagonist BN 52021 reversed this effect of PAF. Pretreatment with CGS 13080 attenuated the marked hypotensive effect of PAF but failed to reverse its necrotic or arrhythmogenic effects. These findings indicate that platelet activation contributes to the necrosis and hypotension following coronary ligation and that platelet-activating factor may contribute to this. The ameliorating effects of platelet antiserum or BN 52021 support the concept that inhibition of platelet activity may have a useful role in the treatment of acute myocardial infarction.
在兔身上评估了血小板活性改变对冠状动脉结扎30分钟期间心律失常、血流动力学及坏死范围的影响。通过静脉注射血小板抗血清（1ml/kg静脉注射）使血小板计数降至对照值的1%以下，坏死组织体积从23±2%降至15±1%，P<0.01（以左心室总体积的百分比表示），并减轻了缺血的降压作用。用血小板活化因子（PAF）拮抗剂BN 52021预处理也减轻了冠状动脉结扎所致的低血压和坏死，分别为23±2%和14±1%，P<0.01。用血栓素拮抗剂CGS 13080预处理减轻了对缺血的降压反应，但对坏死面积只有非常小的影响。冠状动脉结扎10分钟后给予PAF显著增加了坏死组织体积，达36±2%，P<0.01，并导致12只动物中有10只发生室颤和血流动力学崩溃。用血小板抗血清或PAF拮抗剂BN 52021预处理可逆转PAF的这种作用。用CGS 13080预处理减轻了PAF显著的降压作用，但未能逆转其坏死或致心律失常作用。这些发现表明血小板活化促成冠状动脉结扎后的坏死和低血压，且血小板活化因子可能也参与其中。血小板抗血清或BN 52021的改善作用支持了抑制血小板活性在急性心肌梗死治疗中可能具有有益作用的观点。
