AJP - Gastrointestinal and Liver Physiology, Vol 264, Issue 2 383-G389, Copyright © 1993 by American Physiological Society

ARTICLES

Intracellular free Mg2+ with pH changes in cultured epithelial cells

G. A. Quamme
Department of Medicine, University of British Columbia, University Hospital, Vancouver, Canada.

Intracellular pH (pHi) alters cytosolic concentrations of electrolytes, including Ca2+ and Na+. The present studies determined the effect of pHi on intracellular free Mg2+ activity in two epithelial cell lines: one possessing absorptive and secretory functions (Caco-2 intestinal cells) and the second, an absorptive kidney cell line derived from the opossum kidney (OK).pHi and spatial H+ distribution were assessed by 2',7'-bis(carboxyethyl)-5(6')-carboxyfluorescein after an NH4+ pulse to provide rapid changes in pHi. [Mg2+]i, [Ca2+]i, and [Na+]i were measured by fluorescence techniques. [Mg2+]i and spatial Mg2+ distribution within single cells were not changed with rapid alkalinization and acidification procedures in both intestinal and renal cell lines. Alkalinization results in significant increases in [Ca2+]i and [Na+]i that return to basal levels after acidification in both Caco-2 and OK cell lines. These studies indicate that [Mg2+]i is not altered with changes in pHi and suggest that [Mg2+]i is maintained by means not related to pHi in these epithelial cells.

This article has been cited by other articles:

				M. Schweigel and H. Martens Anion-dependent Mg2+ influx and a role for a vacuolar H+-ATPase in sheep ruminal epithelial cells Am J Physiol Gastrointest Liver Physiol, June 9, 2003; 285(1): G45 - G53. [Abstract] [Full Text] [PDF]