Cyclic nucleotide-gated cation channels mediate sodium and calcium influx in rat colon.
Cyclic nucleotide-gated cation channels mediate sodium and calcium influx in rat colon.
复制标题
环状核苷酸门控阳离子通道介导大鼠结肠中钠和钙的流入。
DOI：
10.1152/ajpcell.2000.278.2.c336
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发表时间：
2000
期刊：
影响因子：
--
通讯作者：
Guggino,SE
中科院分区：
文献类型：
--
作者：
Qiu,W;Lee,B;Lancaster,M;Xu,W;Leung,S;Guggino,SE
We found mRNA for the three isoforms of the cyclic nucleotide-gated nonselective cation channel expressed in the mucosal layer of the rat intestine from the duodenum to the colon and in intestinal epithelial cell lines in culture. Because these channels are permeable to sodium and calcium and are stimulated by cGMP or cAMP, we measured 8-bromo-cGMP-stimulated sodium-mediated short-circuit current (Isc) in proximal and distal colon and unidirectional45Ca2+fluxes in proximal colon to determine whether these channels could mediate transepithelial sodium and calcium absorption across the colon. Sodium-mediatedIsc, stimulated by 8-bromo-cGMP, were inhibited by dichlorobenzamil andl-cis-diltiazem, blockers of cyclic nucleotide-gated cation channels, suggesting that these ion channels can mediate transepithelial sodium absorption. Sodium-mediatedIscand net transepithelial45Ca2+absorption were stimulated by heat-stable toxin fromEscherichia colithat increases cGMP. Addition ofl-cis-diltiazem inhibited the enhanced transepithelial absorption of both ions. These results suggest that cyclic nucleotide-gated cation channels simultaneously increase net sodium and calcium absorption in the colon of the rat.
