Inhibitory effect of ATP-sensitive K+ channel regulators on forskolin-stimulated short-circuit current across the isolated mucosa of the rat colon
✍ Scribed by Yu Huang; P. Y. D. Wong
- Publisher
- John Wiley and Sons
- Year
- 1996
- Tongue
- English
- Weight
- 513 KB
- Volume
- 168
- Category
- Article
- ISSN
- 0021-9541
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✦ Synopsis
Forskolin concentration-dependently increased the short-circuit current (IJ across the isolated mucosa of rat colon, which was carried mainly by CI secretion from the mucosal membrane. The sulfonylureas such as glibenclamide, tolbutamide, glipizide and the ATP-sensitive K+ channel opener cromakalim inhibited the forskolin (1 FM)-induced increase of short-circuit current (AIsc) when these drugs were applied to the basolateral side. The rank order of potency for inhibition of Al,, was: glibenclamide > cromakalim > tolbutamide > glipizide. Glibenclamide (1 00 pM) and cromakalim (1 00 pM) caused transient or small reduction of the A231 87-induced AIs(: when applied to the basolateral side. Glibenclamide, tolbutamide and cromakalim decreased the forskolin-induced AI,< when applied to the mucosal side; however, the responses produced by basolateral application were greater and faster than those elicited by mucosal application. None of these four agents affected the basal transepithelial current. The results indicate that the CAMP-dependent CI-secretion in the rat colon could be modulated by ATPsensitive K' channel regulators. o 1996 Wiley-Liss,