Cellular distribution of gastric chief cell protein kinase C activity: differential effects of diacylglycerol, phorbol esters, carbachol, and cholecystokinin.
Cellular distribution of gastric chief cell protein kinase C activity: differential effects of diacylglycerol, phorbol esters, carbachol, and cholecystokinin.
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胃主细胞蛋白激酶 C 活性的细胞分布：二酰基甘油、佛波酯、卡巴胆碱和胆囊收缩素的不同作用。
DOI：
10.1002/jcb.240480115
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发表时间：
1992
影响因子：
4
通讯作者：
Raufman,JP
中科院分区：
文献类型：
--
作者：
Raffaniello,RD;Raufman,JP
用乙醇或胆囊收缩素（CCK）刺激主细胞可产生肌醇三磷酸（IP3）和二酰基甘油（DAG）。虽然ip3增加细胞钙浓度，从而刺激胃蛋白酶原分泌，但DAG及其靶蛋白激酶C （PKC）的作用尚不清楚。为了研究PKC活性的细胞分布与胃蛋白酶原分泌的关系，我们测定了分散的豚鼠胃主细胞的胞质和膜组分的PKC活性。为了验证我们的实验，我们研究了磷酯PMA的作用。PMA引起胃蛋白酶原分泌和膜相关PKC活性快速、剂量依赖性地增加6倍。同样，胃蛋白酶原分泌的剂量-反应曲线和膜渗透DAG（1 -油基- 2 -乙酰甘油）诱导的膜相关PKC活性的增加是重叠的。相比之下，CCK （0.1 nM至1.0 μM）和carbachol （0.1 μM至1.0 mM）导致胃蛋白酶原分泌增加4倍，但没有改变PKC活性的分布。这些结果表明，在胃主细胞中，PMA和DAG诱导的胃蛋白酶原分泌伴随着膜相关PKC活性的增加。然而，PKC活性的细胞分布不受CCK或苯酚的影响。
Stimulation of chief cells with carbachol or cholecystokinin (CCK) results in the production of inositol trisphosphate (IP3) and diacylglycerol (DAG). Although IP3increases cell calcium concentration, thereby stimulating pepsinogen secretion, the role of DAG and its target, protein kinase C (PKC), is less clear. To examine the relation between the cellular distribution of PKC activity and pepsinogen secretion, we determined PKC activity in cytosolic and membrane fractions from dispersed chief cells from guinea pig stomach. To validate our assay, we studied the actions of the phorbol ester PMA. PMA caused a rapid, dose‐dependent, 6‐fold increase in pepsinogen secretion and membrane‐associated PKC activity. Similarly, dose‐response curves for pepsinogen secretion and the increase in membrane‐associated PKC activity induced by a membrane‐permeant DAG (1‐oleoyl‐2‐acetylglycerol) were superimposable. In contrast, CCK (0.1 nM to 1.0 μM) and carbachol (0.1 μM to 1.0 mM) caused a 4‐fold increase in pepsinogen secretion, but did not alter the distribution of PKC activity. These results indicate that in gastric chief cells, PMA‐and DAG‐induced pepsinogen secretion is accompanied by increased membrane‐associated PKC activity. However, the cellular distribution of PKC activity is not altered by CCK or carbachol.