INDUCTION OF AMILORIDE‐SENSITIVE SODIUM TRANSPORT IN THE INTESTINES BY ADRENAL STEROIDS *
INDUCTION OF AMILORIDE‐SENSITIVE SODIUM TRANSPORT IN THE INTESTINES BY ADRENAL STEROIDS *
复制标题
肾上腺类固醇诱导肠内阿米洛利敏感的钠转运 *
DOI：
10.1111/j.1749-6632.1981.tb15458.x
复制
发表时间：
1981
影响因子：
5.2
通讯作者：
U. Hopfer
中科院分区：
文献类型：
--
作者：
P. Will;R. DeLisle;R. Cortright;U. Hopfer
Previous work from this laboratory has demonstrated that mineralocorticoids and glucocorticoids cause the epithelium of the rat descending colon to acquire sodium transport that is inhibitable by micromolar concentrations of the diuretic amiloride.1-4 The induction of the amiloride-sensitive sodium transporter produces an increase of the tissue conductance, the transepithelial potential, and the short-circuit current. Using a sodium-deficient diet as a means for elevating endogenous aldosterone levels, we have also noticed an increase in the activity of the (Na+K)-ATPase.* The first parameter to change in the descending colon was the sensitivity of the short-circuit current to ami1oride.l. Subsequently, the activity of the (Na+K) -ATPase is probably elevated by aldosterone as a secondary effect of the increased luminal conductance to sodium, since the properties of the colon from sodium-depleted animals soon revert to those of the colon from control anima1s.l For example, the sensitivity of the short-circuit current to amiloride is lost with a half-time of -14 h.l In a previous communication,' we have presented evidence that other regions of the gastrointestinal tract besides the descending colon acquire the amiloridesensitive transporter. Since glucocorticoids alter the (Na+K) -ATPase activity and electrolyte and water transport in both the small and large intestine,4-10 it was the objective of this study to examine the regulation of sodium transport in selected regions of the rat gastrointestinal tract by glucocorticoids and mineralocorticoids. The effects of adrenal steroids on the intestinal epithelium were studied by changing steroid levels in vivo and measuring in vitro changes in the electrical parameters of transport (short-circuit current, transepithelial potential, and tissue conductance), in the mechanism of transport (determined with inhibitors, such as amiloride), and in the activity of key membrane-bound and metabolic enzymes. The time course of these effects of aldosterone (the physiological
