Cozza E N, Vila M C, Acevedo-Duncan M, Gomez-Sanchez C E, Farese R V
Department of Internal Medicine, College of Medicine, University of South Florida, Tampa.
J Steroid Biochem. 1990 Feb;35(2):343-51. doi: 10.1016/0022-4731(90)90294-3.
Effects of ACTH on the production of diacylglycerol (DAG) and translocation of protein kinase C were studied in primary cultures of calf adrenal glomerulosa cells. To study DAG production two different labeling protocols were used: (a) cells were prelabeled for 3 days with [2-3H]glycerol before ACTH addition; (b) ACTH and [2-3H]glycerol were added simultaneously to cells. In both cases, ACTH provoked rapid increases in the labeling of DAG which were maximal in 2 min, dose-dependent, and paralleled by increases in DAG mass. ACTH also increased the labeling of total glycerolipids including phosphatidic acid (PA), phosphatidylinositol, phosphatidylethanolamine, phosphatidylcholine and triacylglycerol. In both labeling protocols, the rates of increase in the labeling of DAG and PA were greater than those of other glycerolipids. Our results indicate that ACTH rapidly increases DAG, at least partly by stimulating the de novo synthesis of PA. In addition, we found that ACTH, like phorbol esters, stimulated the apparent translocation of immunoreactive protein kinase C from the cytosol to the membrane fraction.
在小牛肾上腺球状带细胞原代培养物中研究了促肾上腺皮质激素（ACTH）对二酰基甘油（DAG）生成及蛋白激酶C转位的影响。为研究DAG生成，采用了两种不同的标记方案：（a）在添加ACTH之前，用[2-³H]甘油对细胞进行预标记3天；（b）将ACTH和[2-³H]甘油同时添加到细胞中。在这两种情况下，ACTH均引发DAG标记的快速增加，在2分钟时达到最大值，呈剂量依赖性，且与DAG量的增加平行。ACTH还增加了包括磷脂酸（PA）、磷脂酰肌醇、磷脂酰乙醇胺、磷脂酰胆碱和三酰甘油在内的总甘油脂质的标记。在两种标记方案中，DAG和PA标记的增加速率均大于其他甘油脂质。我们的结果表明，ACTH至少部分通过刺激PA的从头合成来快速增加DAG。此外，我们发现，ACTH与佛波酯一样，刺激免疫反应性蛋白激酶C从胞质溶胶向膜部分的明显转位。
