Rittenhouse-Simmons S
J Biol Chem. 1980 Mar 25;255(6):2259-62.
Human platelets incubated with thrombin and indomethacin (50 microgram/ml) exhibit an accumulation of diglyceride larger and more persistent than that observed for platelets incubated with thrombin alone. The accumulation appears to be due to the impaired metabolism of diglyceride by diglyceride lipase. In preparations of broken platelets, indomethacin leads to inhibition of diglyceride lipase. A similar inhibition can be achieved by the addition of soybean lipoxidase, and both inhibitions can be counteracted by reduced glutathione. Further, hydroperoxyeicosatetraenoic acid (100 microM) markedly depresses diglyceride lipase activity, whereas neither the hydroxy derivative nor eicosatetraenoic acid displays a comparable effect. Indomethacin at concentrations comparable to those impairing diglyceride lipase does not inhibit diglyceride kinase. This report constitutes the first evidence for the functioning of diglyceride lipase in normal stimulated platelets, and points to a possible role for fatty acid hydroperoxides in governing the activity of this enzyme.
与凝血酶和吲哚美辛（50微克/毫升）一起孵育的人血小板，其二酰甘油的积累比仅与凝血酶孵育的血小板更大且更持久。这种积累似乎是由于二酰甘油脂肪酶对二酰甘油的代谢受损所致。在破碎血小板的制剂中，吲哚美辛会导致二酰甘油脂肪酶受到抑制。通过添加大豆脂氧化酶也可实现类似的抑制作用，并且这两种抑制作用均可被还原型谷胱甘肽抵消。此外，氢过氧化二十碳四烯酸（100微摩尔）可显著降低二酰甘油脂肪酶的活性，而羟基衍生物和二十碳四烯酸均未表现出类似的作用。与损害二酰甘油脂肪酶的浓度相当的吲哚美辛不会抑制二酰甘油激酶。本报告构成了二酰甘油脂肪酶在正常受刺激血小板中发挥作用的首个证据，并指出脂肪酸氢过氧化物在调节该酶活性方面可能发挥的作用。
