| First Author | Charney AN | Year | 2001 |
| Journal | Am J Physiol Gastrointest Liver Physiol | Volume | 280 |
| Issue | 2 | Pages | G216-21 |
| PubMed ID | 11208543 | Mgi Jnum | J:68062 |
| Mgi Id | MGI:1931994 | Doi | 10.1152/ajpgi.2001.280.2.G216 |
| Citation | Charney AN, et al. (2001) Effect of E. coli heat-stable enterotoxin on colonic transport in guanylyl cyclase C receptor-deficient mice. Am J Physiol Gastrointest Liver Physiol 280(2):G216-21 |
| abstractText | We studied the functional importance of the colonic guanylyl cyclase C (GCC) receptor in GCC receptor-deficient mice. Mice were anesthetized with pentobarbital sodium, and colon segments were studied in Ussing chambers in HCO3- Ringer under short-circuit conditions. Receptor-deficient mouse proximal colon exhibited similar net Na+ absorption, lower net Cl- absorption, and a negative residual ion flux (J(R)), indicating net HCO3- absorption compared with that in normal mice. In normal mouse proximal colon, mucosal addition of 50 nM Escherichia coli heat-stable enterotoxin (STa) increased the serosal-to-mucosal flux of Cl- (J(s-->m)(Cl)) and decreased net Cl- flux (J(net)(Cl)) accompanied by increases in short-circuit current (I(sc)), potential difference (PD), and tissue conductance (G). Serosal STa had no effect. In distal colon neither mucosal nor serosal STa affected ion transport. In receptor-deficient mice, neither mucosal nor serosal 500 nM STa affected electrolyte transport in proximal or distal colon. In these mice, 1 mM 8-bromo-cGMP produced changes in proximal colon J(s-->m)(Cl) and J(net)(Cl), I(sc), PD, G, and J(R) similar to mucosal STa addition in normal mice. We conclude that the GCC receptor is necessary in the mouse proximal colon for a secretory response to mucosal STa. |
