MECHANISM OF CORTICOTROPIN ACTION IN RAT ADRENAL-CELLS .1. EFFECTS OF INHIBITORS OF PROTEIN-SYNTHESIS AND OF MICROFILAMENT FORMATION ON CORTICOSTERONE SYNTHESIS
MECHANISM OF CORTICOTROPIN ACTION IN RAT ADRENAL-CELLS .1. EFFECTS OF INHIBITORS OF PROTEIN-SYNTHESIS AND OF MICROFILAMENT FORMATION ON CORTICOSTERONE SYNTHESIS
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DOI：
10.1016/0304-4165(78)90027-2
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发表时间：
1978-01-01
期刊：
影响因子：
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通讯作者：
JEFCOATE, CR
中科院分区：
文献类型：
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作者：
CRIVELLO, JF;JEFCOATE, CR
通过使用一系列针对每种功能的抑制剂来评估蛋白质合成以及微管和微丝的形成对大鼠肾上腺细胞悬液中 ACTH 刺激的类固醇生成的贡献。五种蛋白质合成抑制剂（放线菌酮、嘌呤霉素、杀稻瘟菌素 S、茴香霉素和木霉菌素）各自对 ACTH 刺激的类固醇生成具有时间依赖性抑制作用。在前 30 分钟内，类固醇生成受到的抑制比蛋白质合成受到更广泛的抑制，此后抑制剂对类固醇生成的有效性减弱，但对蛋白质合成的抑制却没有。在高水平的抑制剂下没有观察到逆转效应。一种微丝形成抑制剂（细胞松弛素 B）和 4 种微管形成抑制剂（秋水仙碱、鬼臼毒素、硫酸长春碱和灰黄霉素）抑制类固醇生成，但不抑制蛋白质合成，并且长时间孵育后没有任何逆转作用。所有 10 种抑制剂的作用均被证明是完全可逆的。肾上腺细胞的细胞灌注表明，添加所有蛋白质合成抑制剂后类固醇生成的衰减与从培养基中去除 ACTH 后的衰减相似（t1/2 [半衰期] = 4-6 分钟）。去除抑制剂后的抑制恢复彼此相似，并且与细胞的初始 ACTH 刺激相当（滞后 3-5 分钟，t1/2 = 7-9 分钟）。硫酸长春花碱观察到类似的抑制和恢复动力学，而氨鲁米特对细胞色素 P-450scc 的直接抑制在 1 分钟内完成，并迅速逆转。将每种抑制剂（所有类别）注射到垂体切除的大鼠体内，可抑制 ACTH 导致的血浆皮质酮升高。所有抑制剂也降低了从这些大鼠分离的肾上腺线粒体中胆固醇与细胞色素 P-450scc 的结合程度。血浆皮质酮的降低与细胞色素 P-450scc 结合的胆固醇的降低直接相关（r [相关系数] = 0.94）。蛋白质合成和类固醇生成必须紧密结合，可能是因为需要不稳定的蛋白质将胆固醇转运至细胞色素 P-450scc。清楚地表明微管和微丝参与了这一过程。
The contributions of protein synthesis and formation of microtubules and microfilaments to ACTH-stimulated steroidogenesis in rat adrenal cell suspensions was assessed by use of a series of inhibitors to each function. Five inhibitors of protein synthesis (cycloheximide, puromycin, blastocidin S, anisomycin and trichodermin) each exhibited time-dependent inhibition of ACTH-stimulated steroidogenesis. For the first 30 min, steroidogenesis was more extensively inhibited than protein synthesis, after which the effectiveness of the inhibitors diminished on steroidogenesis but not on protein synthesis. The reversal effect was not observed at high levels of inhibitors. One inhibitor of microfilament formation (cytochalasin B) and 4 inhibitors of microtubule formation (colchicine, podophyllotoxin, vinblastine sulfate and griseofulvin) inhibited steroidogenesis without inhibiting protein synthesis and without any reversal effect with prolonged incubation. The actions of all 10 inhibitors were shown to be fully reversible. Cell superfusion of adrenal cells showed that the decay of steroidogenesis upon addition of all the protein synthesis inhibitors was similar to decay upon removal of ACTH from the medium (t1/2 [half life] = 4-6 min). Recoveries from inhibition upon removal of the inhibitors were similar to each other and comparable to initial ACTH stimulation of the cells (lag of 3-5 min, t1/2 = 7-9 min). Similar kinetics of inhibition and recovery were observed for vinblastine sulfate while a direct inhibition of cytochrome P-450scc by aminoglutethimide was complete within 1 min and was rapidly reversed. Injection of each inhibitor (all classes) into hypophysectomized rats inhibited the elevation of plasma corticosterone by ACTH. The extent of cholesterol combination with cytochrome P-450scc in adrenal mitochondria isolated from these rats was also decreased by all of the inhibitors. Decreases in plasma corticosterone correlated directly with decreases in cholesterol combination with cytochrome P-450scc (r [correlation coefficient] = 0.94). Protein synthesis and steroidogenesis must be intimately coupled probably due to the requirement of a labile protein for cholesterol transport to cytochrome P-450scc. An involvement of microtubules and microfilaments in this process was clearly indicated.