Activation of gastric mucosal calcium channels by epidermal growth factor.
Activation of gastric mucosal calcium channels by epidermal growth factor.
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表皮生长因子激活胃粘膜钙通道。
DOI：
10.1016/0020-711x(93)90486-x
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发表时间：
1993
期刊：
影响因子：
--
通讯作者：
Slomiany,BL
中科院分区：
文献类型：
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作者：
Liu,J;Fekete,Z;Slomiany,A;Slomiany,BL
1.用麦胚凝集素亲和层析法从胃粘膜上皮细胞膜中分离出胃粘膜钙通道复合物。2.用[3 H] PN 200 -110标记后的复合物重构为磷脂酰胆碱囊泡，其表现出活性45 Ca 2+摄取到囊泡内空间中，如通过La 3+置换和渗透压测量所证明的。~（45）Ca ~（2+）的吸收不受钠、钾梯度的影响，表明该过程具有电中性。3.在ATP存在下，胃粘膜通道对表皮生长因子结合的反应是钙通道的55和170 kDa亚基的蛋白酪氨酸磷酸化增加。4.磷酸化的通道重建成囊泡后，显示在48%以上的45 Ca 2+摄取，从而表明酪氨酸激酶参与EGF依赖性激活的钙通道。5.结果表明表皮生长因子在维持胃粘膜钙稳态中的重要性。
1. Gastric mucosal calcium channel complex was isolated from the solubilized epithelial cell membranes by affinity chromatography on wheat germ agglutinin. 2. The complex following labeling with [3H] PN200-110 was reconstituted into phosphatidylcholine vesicles which exhibited active 45Ca2+ uptake into intravesicular space as evidenced by La3+ displacement and osmolarity measurements. The 45Ca2+ uptake was independent of sodium and potassium gradients indicating the electroneutral nature of the process. 3. The gastric mucosal channels on epidermal growth factor binding in the presence of ATP responded by an increase in protein tyrosine phosphorylation of 55 and 170 kDa subunits of calcium channel. 4. The phosphorylated channels following reconstitution into vesicles displayed at 48% greater 45Ca2+ uptake, thus indicating the tyrosine kinase involvement in EGF dependent activation of calcium channel. 5. The results point towards the importance of epidermal growth factor in the maintenance of gastric mucosal calcium homeostasis.