H and HCO3 transport across the basolateral membrane of the parietal cell.
H and HCO3 transport across the basolateral membrane of the parietal cell.
复制标题
H 和 HCO3 穿过壁细胞的基底外侧膜运输。
DOI：
10.1111/j.1749-6632.1989.tb25183.x
复制
发表时间：
1989
影响因子：
5.2
通讯作者：
Negulescu,PA
中科院分区：
文献类型：
--
作者：
Machen,TE;Townsley,MC;Paradiso,AM;Wenzl,E;Negulescu,PA
哺乳动物胃的壁细胞（PC）负责分泌大量高浓度HCl（pH< 1.0）进入胃腔，通常每天三次。这在细胞内pH（pHi）的调节方面产生了特殊的问题，因为细胞必须产生大的质子跨细胞通量，以及防止细胞因被动力和代谢废物在高活性细胞中的积累而酸化的正常趋势。为了维持相对恒定的pHi，PC必须具有用于调节pHi的有效的膜机制，并且在顶膜和基底外侧膜处的转运蛋白的活性之间必须存在非常好的协调。通常认为，通过与K和Cl渗透性途径平行的众所周知的HIK-ATP酶的操作，发生跨顶膜的H分泌：K和Cl从细胞中泄漏出来，然后K通过ATP酶交换H，最终结果是HCl的分泌。在这个过程中，细胞质产生一个OH，每一个H分泌到管腔中，这个基地最终被运送到基底外侧膜进入血液。我们4、5和Muallem、Sachs及其同事6都表明，PC基底外侧膜中存在Na/H和Cl/HCO 3交换剂。最近的实验还显示了Na/HC 03共转运蛋白。本文回顾了我们实验室的相关实验，并显示了各种转运蛋白的活性如何在由强有力的兴奋剂组胺加异丁基甲基黄嘌呤（IBMX），一种有效的磷酸二酯酶抑制剂激活HCl分泌过程中发生变化。
The parietal cells (PC) of the mammalian stomach are responsible for secreting large amounts of highly concentrated HC1 (pH< 1.0) into the gastric lumen, usually three times a day. This creates special problems in terms of the regulation of intracellular pH (pHi), because the cells have to generate large transcellular fluxes of protons as well as guard against the normal tendencies of cells to acidify from passive forces and from the accumulation of metabolic waste products in a highly active cell.'To maintain a relatively constant pHi the PC must have effective membrane mechanisms for regulating pHi, and there must be very good coordination among the activities of the transporters at the apical and basolateral membranes.H secretion across the apical membrane is generally accepted to occur by the operation of the well-known HIK-ATPase in parallel with K and C1 permeability pathway^:^,^ K and C1 leak out of the cell, K then recycles through the ATPase in exchange for H, and the net result is the secretion of HCl. During this process the cytoplasm produces one OH for every H secreted into the lumen, and this base eventually is transported across the basolateral membrane into the blood. Both we4, 5 and Muallem, Sachs, and their colleagues6 have shown that there are Na/H and Cl/HC03 exchangers in the basolateral membranes of PC. Recent experiments' have also shown a Na/HC03 cotransporter. This paper reviews the relevant experiments from our laboratory and shows how the activities of the various transporters change during activation of HC1 secretion by the powerful stimulants histamine plus isobutylmethylxanthine (IBMX), a potent phosphodiesterase inhibitor.