Studies on the effect of insulin-like growth factor-I on catecholamine secretion from chromaffin cells.
Studies on the effect of insulin-like growth factor-I on catecholamine secretion from chromaffin cells.
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胰岛素样生长因子-I对嗜铬细胞分泌儿茶酚胺影响的研究。
DOI：
10.1111/j.1471-4159.1990.tb02340.x
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发表时间：
1990
影响因子：
4.7
通讯作者：
Perlman,RL
中科院分区：
文献类型：
--
作者：
Dahmer,MK;Hart,PM;Perlman,RL
在无血清培养基中培养的嗜铬细胞在高K+（55 mM）刺激下分泌的儿茶酚胺储备百分比低于在含血清培养基中培养的细胞。向无血清培养基中添加胰岛素样生长因子I（IGF-I）可将高K+刺激的儿茶酚胺分泌恢复至血清处理培养物中观察到的水平。相反，向含血清培养基中添加IGF-I对儿茶酚胺分泌的影响很小。这些结果表明，血清中含有IGF-I或其他维持嗜铬细胞分泌反应的因子。IGF-I不仅增强了高K+刺激的儿茶酚胺分泌，而且还增强了烟碱激动剂二甲基苯基哌嗪、二氢吡啶激动剂Bay K 8644和Ba 2+引起的分泌。IGF-I不影响儿茶酚胺分泌对细胞外Ca 2+浓度的依赖性，也不影响分泌的时间过程。使用45 Ca 2+的实验表明，IGF-I处理增强了细胞对Ca 2+的摄取。当通过毛地黄皂苷处理使细胞透化时，IGF-I处理的细胞的Ca 2+依赖性儿茶酚胺分泌略高于未处理的细胞，但始终高于未处理的细胞。我们的研究结果表明，IGF-I可能部分通过增加Ca 2+进入细胞，部分通过影响Ca 2+进入远端的步骤来增强儿茶酚胺分泌。
Chromaffin cells cultured in serum‐free medium secreted a smaller percentage of their catecholamine stores in response to stimulation by high K+(55 mM) than did cells cultured in serum‐containing medium. Addition of insulin‐like growth factor‐I (IGF‐I) to serum‐free medium restored high K+‐stimulated catecholamine secretion to the levels seen in serum‐treated cultures. In contrast, addition of IGF‐I to serum‐containing medium had little effect on catecholamine secretion. These results suggest that serum contains IGF‐I or another factor that maintains the secretory responsiveness of chromaffin cells. IGF‐I not only enhanced high K+‐stimulated catecholamine secretion, but also augmented secretion elicited by the nicotinic agonist dimethyl‐phenylpiperazinium, the dihydropyridine agonist Bay K 8644, and Ba2+. IGF‐I did not affect the dependence of catecholamine secretion on extracellular Ca2+concentration nor did it affect the time course of secretion. Experiments using45Ca2+demonstrated that IGF‐I treatment enhanced Ca2+uptake into the cells. When cells were permeabilized by treatment with digitonin, Ca2+‐dependent catecholamine secretion was slightly, but consistently, greater from IGF‐I‐treated cells than from untreated cells. Our results suggest that IGF‐I may enhance catecholamine secretion partly by increasing Ca2+entry into the cells and partly by affecting a step distal to Ca2+entry.