Effect of acute metabolic alkalosis and acidosis on intestinal electrolyte transport in vivo
- 1 November 1980
- journal article
- research article
- Published by American Physiological Society in American Journal of Physiology-Gastrointestinal and Liver Physiology
- Vol. 239 (5), G427-G436
- https://doi.org/10.1152/ajpgi.1980.239.5.g427
Abstract
The effects of acute metabolic alkalosis and acidosis on intestinal electrolyte transport were studied in adult Sprague-Dawley rats. Animals were made alkalotic or acidotic by gavage feeding of 1 M solutions of NaCl (pH = 7.42), NaHCO3 (pH = 7.52), NH4Cl (pH = 7.18) or 0.75 M (NH4)2SO4 (pH = 7.21). After 1-3 h, animals were anesthetized and prepared for in vivo perfusion of the jejunum, ileum and colon. The jejunum exhibited increased net K absorption in alkalosis and decreased K absorption in acidosis. In the ileum, net Na absorption and K secretion were decreased and bicarbonate secretion was increased in alkalosis and opposite effects were observed in acidosis. The ileal lumen minus blood gradient for PCO2 [partial pressure of CO2] (an index of H+ secretion) was greater in acidotic than in alkalotic animals.The levels of ileal Na, bicarbonate and K transport and the PCO2 gradient correlated well with the plasma pH and bicarbonate concentration in individual animals. In the colon, net bicarbonate secretion and Cl- absorption increased and K secretion decreased in alkalosis and opposite effects were observed in acidosis. The colonic lumen minus blood PCO2 gradient was not affected by acid-base balance. Colonic bicarbonate transport correlated with the plasma Cl- concentration and with the plasma pH. The acid-base disorders had no effect on transmural potential difference. Acute metabolic alkalosis and acidosis probably alter Na and H+ transport in the ileum and Cl- and bicarbonate transport in the colon.This publication has 4 references indexed in Scilit:
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