Sévilla E, Valette A, Gastaldi M, Boyer J, Vérine A
INSERM U 260, Faculté de Médicine, Marseille, France.
Biochem Pharmacol. 1991 Jun 15;41(12):2005-9. doi: 10.1016/0006-2952(91)90142-r.
We examined the effects of the in vivo administration of ethanol on lipolytic activities assayed in rat post-heparin heart effluents, that hydrolyse tri-, di- and monoacylglycerol. Properties of triacylglycerol lipase (TAGL) are typical of lipoprotein lipase (LPL) whereas diacylglycerol (DAGL) and monoacylglycerol (MAGL) lipase activities hydrolyse sequentially the products of LPL action. After 15 days of ethanol intake, TAGL, DAGL and MAGL activities in post-heparin heart effluents were decreased respectively by 25, 38 and 22%; after 30 days, the decreases amounted to 81, 79 and 71%. After 30 days, but not after 15 days, ethanol increased the levels of triacylglycerol in plasma. Ethanol intake concomitantly decreased TAGL and DAGL activities in post-heparin effluents and in heart tissue extracts, whereas MAGL activity was decreased only in the latter extracts. We conclude that ethanol intake causes a marked impairment in heart LPL and in two closely-related heparin-releasable activities, seemingly by altering the production of a catalytically active enzyme. A distinct heparin-unreleasable MAGL appears to exist in heart, that could be ethanol-insensitive. Overall, the results suggest that a LPL-related alteration in fatty acid supply could contribute to the toxicity of ethanol in heart.
我们研究了体内给予乙醇对大鼠肝素化心脏流出液中脂解活性的影响，该流出液可水解三酰甘油、二酰甘油和单酰甘油。三酰甘油脂肪酶（TAGL）的特性与脂蛋白脂肪酶（LPL）典型特性相似，而二酰甘油脂肪酶（DAGL）和单酰甘油脂肪酶（MAGL）活性则依次水解LPL作用的产物。摄入乙醇15天后，肝素化心脏流出液中的TAGL、DAGL和MAGL活性分别降低了25%、38%和22%；30天后，降低幅度分别达到81%、79%和71%。30天后，而非15天后，乙醇使血浆中三酰甘油水平升高。摄入乙醇同时降低了肝素化流出液和心脏组织提取物中的TAGL和DAGL活性，而MAGL活性仅在后者提取物中降低。我们得出结论，摄入乙醇会导致心脏LPL以及两种密切相关的肝素可释放活性显著受损，这似乎是通过改变催化活性酶的产生所致。心脏中似乎存在一种独特的肝素不可释放的MAGL，它可能对乙醇不敏感。总体而言，结果表明与LPL相关的脂肪酸供应改变可能导致乙醇对心脏的毒性。
