Cao Y Z, O K, Choy P C, Chan A C
Department of Biochemistry, Faculty of Medicine, University of Manitoba, Winnipeg, Canada.
Biochem J. 1987 Oct 1;247(1):135-40. doi: 10.1042/bj2470135.
Lysophosphatidylcholine is the major lysophospholipid in mammalian tissues and has been shown to be cytolytic at high concentrations. In the present study we demonstrated that the level of lysophosphatidylcholine was significantly increased in the heart of rats fed with a vitamin E-deficient diet. Moreover, the cardiac lysophosphatidylcholine level was decreased in rats fed with a high vitamin E diet. The alterations in cardiac lysophosphatidylcholine level by dietary vitamin E were attributed to the changes in the activity of cardiac phospholipase A. Dietary vitamin E affected both phospholipase A1 and A2 in the same manner, but had no effect on the other major enzymes which are responsible for the metabolism of lysophosphatidylcholine. Kinetic studies revealed that the inhibition of enzyme activity by vitamin E was essentially non-competitive. The accumulation of lysophosphatidylcholine in the rat heart may be one of the underlying biochemical causes of the observed cardiac dysfunctions produced during vitamin E deficiency.
溶血磷脂酰胆碱是哺乳动物组织中的主要溶血磷脂，已证明在高浓度时具有细胞溶解作用。在本研究中，我们证明了喂食维生素E缺乏饮食的大鼠心脏中溶血磷脂酰胆碱水平显著升高。此外，喂食高维生素E饮食的大鼠心脏中溶血磷脂酰胆碱水平降低。饮食中维生素E引起的心脏溶血磷脂酰胆碱水平变化归因于心脏磷脂酶A活性的改变。饮食中的维生素E以相同方式影响磷脂酶A1和A2，但对负责溶血磷脂酰胆碱代谢的其他主要酶没有影响。动力学研究表明，维生素E对酶活性的抑制基本上是非竞争性的。大鼠心脏中溶血磷脂酰胆碱的积累可能是维生素E缺乏期间观察到的心脏功能障碍的潜在生化原因之一。
