Cell Volume Regulation During Hyperosmotic Shrinkage Is Mediated by Na+/K+-ATPase and Na+&#8211;K+&#8211;2Cl Cotransporter in Necturus<
详细信息
下载全文
推荐本文 |
摘要
Cell volume regulation was investigated in gastric surface epithelial cells during hypertonic conditions. Isolated Necturus antral mucosa was perfused on the serosal side with Ringer's solution (pH 7.25, 95%O2/5%CO2) and on the mucosal side successively with 150&#8211;500 mM NaCl. Amiloride, ouabain, and bumetanide were used to experimentally inhibit Na+/H+, Na+/K+ ATPase or Na+&#8211;K+&#8211;2Cl&#8211; ion transporters. Intracellular sodium activity and cell volume changes were measured with liquid sensor microelectrodes. The increase in intracellular sodium activity caused by luminal hyperosmolar exposure was mainly due to cell shrinkage. Inhibition of Na+/K+ ATPase or Na+&#8211;K+&#8211;2Cl&#8211; cotransporter increased hyperosmotic cell shrinkage (−52 卤 5%, −85 卤 19%, and −77 卤 9%for control, ouabain, and bumetanide, respectively). Inhibition of Na+/K+ ATPase increased intracellular sodium activity (from 18 卤 4 to 52 卤 12 mM). Cell volume regulation in gastric epithelial surface cells during mucosal hyperosmolar exposure is maintained by the basolateral Na+&#8211;K+&#8211;2Cl&#8211; cotransporter, while Na+/K+ ATPase maintains sodium balance, but Na+/H+ antiport seems to have a less important role.

© 2004-2018 中国地质图书馆版权所有 京ICP备05064691号 京公网安备11010802017129号

地址:北京市海淀区学院路29号 邮编:100083

电话:办公室:(+86 10)66554848;文献借阅、咨询服务、科技查新:66554700