Hayashi_2003_Am.J.Physiol.Gastrointest.Liver.Physiol_284_G617

Reference

Title : Cholinergic inhibition of electrogenic sodium absorption in the guinea pig distal colon - Hayashi_2003_Am.J.Physiol.Gastrointest.Liver.Physiol_284_G617
Author(s) : Hayashi H , Suzuki T , Yamamoto T , Suzuki Y
Ref : American Journal of Physiology Gastrointest Liver Physiol , 284 :G617 , 2003
Abstract :

Submucosal cholinergic and noncholinergic neurons in intestines have been shown to be involved in regulating epithelial transport functions, particularly stimulating Cl(-) secretion. This study investigates the role of submucosal cholinergic neurons in regulating electrogenic Na(+) absorption in distal colon. Amiloride-sensitive short-circuit current (I(sc)) and (22)Na(+) flux were measured in mucosal and mucosal-submucosal preparations mounted in Ussing chambers. In the mucosal preparation, carbachol (CCh) added to the serosal side inhibited amiloride-sensitive I(sc) and amiloride-sensitive (22)Na(+) absorption. The inhibitory effect of CCh was observed at approximately 0.1 microM, and maximum inhibition of approximately 70% was attained at approximately 30 microM (IC(50) = approximately 1 microM). CCh-induced inhibition of amiloride-sensitive I(sc) was almost totally abolished by 10 microM atropine. Treatment of the tissue with ionomycin markedly reduced amiloride-sensitive I(sc), but a subsequent addition of CCh further decreased it. Also, CCh still had an inhibitory effect, although significantly attenuated, after the tissue had been incubated with a low-Ca(2+) solution containing ionomycin and BAPTA-AM. Applying electrical field stimulation to submucosal neurons in the mucosal-submucosal preparation resulted in inhibition of amiloride-sensitive I(sc), approximately 33% of this inhibition being atropine sensitive. Physostigmine inhibited amiloride-sensitive I(sc), this effect being abolished by atropine. In conclusion, submucosal cholinergic and noncholinergic neurons were involved in inhibiting electrogenic Na(+) absorption in colon. This inhibition by cholinergic neurons was mediated by muscarinic receptor activation.

PubMedSearch : Hayashi_2003_Am.J.Physiol.Gastrointest.Liver.Physiol_284_G617
PubMedID: 12444010

Related information

Citations formats

Hayashi H, Suzuki T, Yamamoto T, Suzuki Y (2003)
Cholinergic inhibition of electrogenic sodium absorption in the guinea pig distal colon
American Journal of Physiology Gastrointest Liver Physiol 284 :G617

Hayashi H, Suzuki T, Yamamoto T, Suzuki Y (2003)
American Journal of Physiology Gastrointest Liver Physiol 284 :G617