Role of the vasopressin V-1 receptor in regulating the epithelial functions of the guinea pig distal colon

Citation
Y. Sato et al., Role of the vasopressin V-1 receptor in regulating the epithelial functions of the guinea pig distal colon, AM J P-GAST, 277(4), 1999, pp. G819-G828
Citations number
46
Language
INGLESE
art.tipo
Article
Categorie Soggetti
da verificare
Journal title
AMERICAN JOURNAL OF PHYSIOLOGY-GASTROINTESTINAL AND LIVER PHYSIOLOGY
ISSN journal
0193-1857 → ACNP
Volume
277
Issue
4
Year of publication
1999
Pages
G819 - G828
Database
ISI
SICI code
0193-1857(199910)277:4<G819:ROTVVR>2.0.ZU;2-D
Abstract
Vasopressin has a wide spectrum of biological action. In this study, the ro le of vasopressin in regulating electrolyte transport in the colon was eluc idated by measuring the short-circuit current (I,,) as well as the Na+, K+, and Cl- flux in a chamber-mounted mucosal sheet. The cytosolic Ca2+ concen tration ([Ca2+](i)) was also measured in fura 2-loaded cells by fluorescenc e imaging. Serosal vasopressin decreased I-sc at 10(-9) M and increased I-s c at 10(-7)-10(-6) M. The decrease in I-sc was accompanied by two effects: one was a decrease in the amiloride-sensitive Na+ absorption, whereas the o ther was an increase in the bumetanide-sensitive K+ secretion. The increase in I-sc was accompanied by an increase in the Cl- secretion that can be in hibited by serosal bumetanide or mucosal diphenylamine-2-carboxylate. Vasop ressin caused an increase in [Ca2+](i) in crypt cells. These responses of I -sc and the [Ca2+](i) increase in crypt cells were all more potently inhibi ted by the vasopressin V-1 receptor antagonist than by the V-2 receptor ant agonist. These results suggest that vasopressin inhibits electrogenic Nai a bsorption and stimulates electrogenic K+ and Cl- secretion. In all of these responses, the V-1 receptor is involved, and the [Ca2+](i) increase may pl ay an important role.