Chronic EtOH administration alters liver Mg2+ homeostasis

Ethanol (EtOH) administration to rats for 4 wk markedly decreased Mg2+content in several tissues, including liver. Total cellular Mg2+accounted for 26.8 ± 2.4 vs. 36.0 ± 1.4 nmol Mg2+/mg protein in hepatocytes from EtOH-fed and control rats, respectively, and paralleled a 13% decrease in cellular ATP content. Stimulation of α1- or β-adrenergic receptor or acute EtOH administration did not elicit an extrusion of Mg2+from liver cells of EtOH-fed rats while releasing 5% of total tissue Mg2+content from hepatocytes of control rats. Despite the 25% decrease in Mg2+content, hepatocytes from EtOH-fed rats did not accumulate Mg2+following stimulation of protein kinase C signaling pathway, whereas control hepatocytes accumulated ∼2 nmol Mg2+· mg protein−1· 4 min−1. Together, these data indicate that Mg2+homeostasis and transport are markedly impaired in liver cells after prolonged exposure to alcohol. The inability of liver cells, and possibly other tissues, to accumulate Mg2+can help explain the reduction in tissue Mg2+content following chronic alcohol consumption.