Hirata F, Stracke M L, Schiffmann E
Department of Environmental Health Sciences, School of Hygiene and Public Health, Johns Hopkins University, Baltimore, MD 21205.
J Steroid Biochem. 1987;27(4-6):1053-6. doi: 10.1016/0022-4731(87)90189-0.
Glucocorticoids induce the synthesis of a family of phospholipase inhibitory proteins, lipocortins. This family of lipocortins includes inhibitory proteins on phospholipase A2, phospholipase C and phosphatidylinositol phospholipase C. Hence, glucocorticoids reduce the formation of prostaglandins and leukotrienes by inhibiting cellular phospholipases, enzymes that degrade membrane phospholipids to release arachidonic acid, a precursor. The induction by glucocorticoids requires 1 h for the synthesis of mRNA and 5 h for the synthesis of proteins in various tissues and cells. However, glucocorticoids often exert their suppressive effects before the induction of lipocortins. This is now attributed to the nonenzymic formation of the adducts between glucocorticoids and lipocortins. These adducts are easily inserted into the membranes and more resistant to digestion of proteases, thus being more biologically potent with respect to suppression of the release of arachidonic acid, a precursor of prostaglandins and leukotrienes.
糖皮质激素可诱导一类磷脂酶抑制蛋白即脂皮质素的合成。该脂皮质素家族包括磷脂酶A2、磷脂酶C和磷脂酰肌醇磷脂酶C的抑制蛋白。因此，糖皮质激素通过抑制细胞磷脂酶来减少前列腺素和白三烯的形成，这些酶可降解膜磷脂以释放花生四烯酸（一种前体物质）。在各种组织和细胞中，糖皮质激素诱导合成信使核糖核酸需要1小时，合成蛋白质需要5小时。然而，糖皮质激素常在脂皮质素诱导之前就发挥其抑制作用。这现在归因于糖皮质激素与脂皮质素之间非酶促形成的加合物。这些加合物很容易插入膜中，并且对蛋白酶消化更具抗性，因此在抑制前列腺素和白三烯的前体花生四烯酸的释放方面具有更强的生物学活性。
