AN ADRENAL TUMOR: CYTOCHROME P-450 AND STEROIDOGENESIS

单层培养小鼠肾上腺肿瘤细胞(Y-1)用于研究 与其侵入性有关的问题，与对其 类固醇合成活性，以及这两个特征之间的关系 新合成的细胞的功能是什么 在Y-1中加入ACTH后发现与线粒体相关的蛋白质 细胞？质膜粘度和血浆粘度的变化有什么影响 膜受体在电场中的重新定位 与细胞对ACTH和霍乱毒素的反应有关的事件？ 在多大程度上可以促进生长和类固醇的生成 通过将细胞注射到LAF1小鼠体内，通过添加 脑下垂体提取物对细胞的培养？ 新蛋白(S)与胆固醇转运的关系 线粒体是通过孵育[~3H]胆固醇油酸盐来研究的--低密度 脂蛋白与侧链断裂被阻断的细胞和 测量线粒体[~3H]胆固醇。膜受体被标记 与荧光配体(ACTH、霍乱毒素和刀豆蛋白A)在 暴露在电场中以估计膜的粘度。 细胞膜中的胆固醇含量通过与 无脂血浆或含胆固醇脂质体。类固醇激素的生成和 比较了细胞在垂体提取物存在下的生长情况。 对动物通过的反应。非离子洗涤剂被用来改善 从Y-1细胞和正常肾上腺细胞中提取线粒体P-450。 肌球蛋白在ACTH反应中的作用是通过测量 肌球蛋白轻链磷酸化程度 在没有ACTH和有ACTH的情况下孵育。 一种环状AMP依赖的蛋白激酶已被发现与 与Y-1细胞的细胞骨架结合。该酶促进磷酸化 七种蛋白质。在Y-1细胞中也发现了蛋白激酶C， 当与佛波醇酯孵育时，显示类固醇合成增加。(D)

Mouse adrenal tumor cells (Y-1) in monolayer culture is being used to study questions related to their invasive properties, to the regulation of their steroidogenic activity, and to the relationship between these two features of the cells as follows: What is the function of the newly synthesized proteins found associated with mitochondria after addition of ACTH to Y-1 cells? What effect do alterations in plasma membrane viscosity and relocation of membrane receptors in an electric field have on the initial events associated with responses of the cells to ACTH and cholera toxin? To what extent can the enhancement of growth and steroidogenesis produced by injection of cells into LAF1 mice be duplicated by addition of pituitary extracts to the cells in culture? The relationship between the new protein(s) and transport of cholesterol to mitochondria is studied by incubating [3H]cholesterol oleate--low density lipoprotein with cells in which side-chain cleavage is blocked and measuring mitochondrial [3H]cholesterol. Membrane receptors are labeled with fluorescent ligands (ACTH, cholera toxin, and Concanavalin A) after exposure to an electrical field to estimate membrane viscosity. Cholesterol content of cell membranes is altered by incubation with lipid-free plasma or cholesterol-containing liposomes. Steroidogenesis and growth of cells in the presence of pituitary extracts are compared with the response to animal passage. Nonionic detergents are used to improve extraction of mitochondrial P-450 from Y-1 cells and normal adrenal cells. The role of myosin in the response to ACTH is studied by measuring the extent of phosphorylation of the myosin light chain when cells are incubated without and with ACTH. A cyclic AMP-dependent protein kinase has been found closely associated with the cytoskeleton of Y-1 cells. The enzyme promotes phosphorylation of seven proteins. Protein kinase C has also been found in Y-1 cells which show increased steroidogenesis when incubated with phorbol esters. (D)