Altered calcium homeostasis in carbon tetrachloride exposed rat hepatocytes.

: In situ perfusion of rat liver with carbon tetrachloride (10-15 mM at a final concentration of lul/ml of mineral oil) resulted in a significant (p less than 0.01) loss of microsomal Ca2+ over 5-15 min of exposure. Mitochondrial Ca2+ content increased sharply (2 fold) with concomitant increase in the cytosolic free Ca2+. The changes were associated with a significant (p less than 0.01) decrease in plasma membrane Ca2+ - ATPase activity, reflected by impaired Ca2+ efflux and Ca2+ exchange properties. Our data indicates that impairment of plasma membrane Ca2+ flux contributes substantially to the overall disruption of calcium homeostasis induced by carbon tetrachloride.