Phorbol esters enhance exocytosis from chromaffin cells by two mechanisms.
Phorbol esters enhance exocytosis from chromaffin cells by two mechanisms.
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佛波酯通过两种机制增强嗜铬细胞的胞吐作用。
DOI：
10.1111/j.1471-4159.1990.tb13302.x
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发表时间：
1990
影响因子：
4.7
通讯作者：
Holz,RW
中科院分区：
文献类型：
--
作者：
Bittner,MA;Holz,RW
用佛波酯如12-O-泰特-radecanoylphorbol acetate（TPA）治疗可迅速增强毛地黄皂苷透化的肾上腺嗜铬细胞分泌[3 H]去甲肾上腺素。当TPA处理延长数小时时，观察到第二个明显的增强效应。这种后一种增强在细胞内Ca 2+浓度为3-30μM时最为显著，并且不需要持续存在膜结合蛋白激酶C来表达。该效应可以通过在TPA中暴露30分钟，然后在无TPA的培养基中暴露数小时来引起。TPA的这种作用被放线菌素D和放线菌酮阻断，表明RNA和蛋白质合成的需要。当用TPA预处理的完整细胞被去极化浓度的K+刺激分泌时，观察到类似的效果。因此，蛋白激酶C通过两种机制增强分泌。一种是快速的，可能反映了即时蛋白磷酸化的影响。另一个发生在几个小时内，需要基因转录和蛋白质合成。
Treatment with phorbol esters such as 12‐O‐tet‐radecanoylphorbol acetate (TPA) rapidly enhances [3H]norepinephrine secretion from digitonin‐permeabilized adrenal chromaffin cells. When TPA treatment was prolonged for several hours, a second distinct enhancing effect was observed. This later enhancement was most prominent at intracellular Ca2+concentrations of 3–30μM, and did not require the continued presence of membrane‐bound protein kinase C for its expression. The effect could be elicited by as little as 30‐min exposure to TPA, followed by several hours in TPA‐freemedium. This effect of TPA was blocked by actinomycin D and cycloheximide, indicating a requirement for RNA and protein synthesis. Similar effects were seen when intact cells that had been pretreated with TPA were stimulated to secrete by depolarizing concentrations of K+. Thus, protein kinase C enhances secretion by two mechanisms. One is rapid and probably reflects the effects of immediate protein phosphorylation. The other occurs over several hours and requires gene transcription and protein synthesis.