Plasma glutathione S-transferase in carbon tetrachloride treated rats and its association to hepatic cytosolic isozymes.

The effect of carbon tetrachloride (CCl4) treatment on plasma and liver cytosolic glutathione S-transferase (GST) activities was investigated in rats. CCl4 was intraperitoneally administered at a dose of 0.5 ml/kg. The elevation of plasma GST activity paralleled the increase of plasma glutamate pyruvate transaminase activity after the administration of CCl4. Liver cytosolic GST activities were significantly decreased by CCl4 treatment. To establish the relationship of plasma GST with liver cytosolic isozymes, Western blot analysis using antibodies against cytosolic GST 1-2 and 3-4 was performed. The Western blots showed the existence of GST 1-2 and 3-4 in plasma at 24 hr after CCl4 treatment. The data thus strongly suggest that cytosolic GSTs are lost from the liver to plasma as a consequence of liver damage. The Western blot analysis of plasma GST may be useful for monitoring liver damage.