Margolis R N, Garfield S A, Cardell R R
Endocrinology. 1979 Jun;104(6):1722-32. doi: 10.1210/endo-104-6-1722.
Biochemical and morphological studies were performed on livers from normal, adrenalectomized (ADX), and ADX and dexamethasone (DEX)-treated rats to investigate the effects of glucocorticoids on microsomal membrane synthesis. Overnight fasted normal, ADX and ADX rats treated 2 or 4 h with DEX received [3H]leucine and [14C]glycerol. Livers were removed, and tissue specimens were prepared for electron microscopy and tissue fractionation. Liver microsomal subfractions were prepared and subsequently washed to produce rough and smooth microsomal membranes. Radioactivity and membrane composition were determined, and glucose-6-phosphatase activity was measured in washed microsomal membranes. Adrenalectomy caused decreased microsomal membrane synthesis. Two and 4 h of DEX administration restored microsomal membrane synthesis to normal levels. ADX also caused an alteration in composition of the microsomal membranes (reflected in decreased phospholipid-protein ratios), which was restored to normal levels by 4 h after DEX administration. The earliest effects of the hormone on membrane synthesis were observed in smooth microsomes as part of a smooth endoplasmic reticulum (SER) proliferation. These findings were supported by observations made with the electron microscope. The proliferating SER was enriched in at least one component: glucose-6-phosphatase. Although the specific relationship of SER to glucocorticoid action remains unclear, the interpretation is offered that SER proliferation and alteration in glucose-6-phosphatase distribution are component parts of the total response of the hepatocyte to glucocorticoids.
对正常大鼠、肾上腺切除（ADX）大鼠以及肾上腺切除并经地塞米松（DEX）处理的大鼠的肝脏进行了生化和形态学研究，以探究糖皮质激素对微粒体膜合成的影响。过夜禁食的正常大鼠、肾上腺切除大鼠以及经地塞米松处理2或4小时的肾上腺切除大鼠接受了[3H]亮氨酸和[14C]甘油。取出肝脏，并制备组织标本用于电子显微镜检查和组织分级分离。制备肝脏微粒体亚组分，随后进行洗涤以产生粗面和滑面微粒体膜。测定放射性和膜成分，并在洗涤后的微粒体膜中测量葡萄糖-6-磷酸酶活性。肾上腺切除术导致微粒体膜合成减少。给予地塞米松2小时和4小时可使微粒体膜合成恢复到正常水平。肾上腺切除术还导致微粒体膜成分发生改变（表现为磷脂-蛋白质比率降低），在给予地塞米松后4小时恢复到正常水平。激素对膜合成的最早影响在作为滑面内质网（SER）增殖一部分的滑面微粒体中观察到。这些发现得到了电子显微镜观察结果的支持。增殖的滑面内质网富含至少一种成分：葡萄糖-6-磷酸酶。尽管滑面内质网与糖皮质激素作用的具体关系仍不清楚，但有人认为滑面内质网增殖和葡萄糖-6-磷酸酶分布改变是肝细胞对糖皮质激素总反应的组成部分。
