ALCOHOLS INDUCE RAPID DEPLETION OF INTRACELLULAR FREE MG2+ IN CEREBRAL VASCULAR MUSCLE-CELLS - RELATION TO CHAIN-LENGTH AND PARTITION-COEFFICIENT

Acute effects of a series of alcohols (methanol, ethanol, n-butanol) on intracellular free magnesium concentration ([Mg2+](i)) in canine cerebral vascular smooth muscle cells was studied using mag-fura-2 and digital imaging microscopy. In 1.2 mM [Mg2+](o), basal [Mg2+](i) was 500 +/- 30 mu M. Exposure Of cells to a low concentration (25 mM) of ethanol, but not methanol, for only 30 s resulted in significant loss of [Mg2+](i). Exposure to 100 mM methanol, ethanol, and butanol for 30 s resulted in a relative order of potency for [Mg2+](i) depletion, where butanol > > ethanol > methanol. The heterogeneous and relative subcellular compartmented concentrations of [Mg2+](i), where perinuclear > nuclear > > peripheral (cytosolic) region, was not significantly altered by the alcohols. The degree of cellular depletion of [Mg2+](i) was directly a function of each alcohol's partition coefficient and chain length. The latter is suggestive of the probability that alcohols promote intracellular depletion of Mg2+ by partitioning in membranes and disordering lipid bilayers.