Difference in liver and serum malathion carboxylesterase and glucose-6-phosphatase in detecting carbon tetrachloride-induced liver damage in rats

Microsome, cytosol and serum malathion carboxylesterase (MaCEst) activity was assessed in rats after single i.p. administration of carbon tetrachloride (CCl4) in doses ranging from 0.05 to 1 ml kg−1. MaCEst activities were compared with those of glucose‐6‐phosphatase (G6‐Pase) as an indicator of endoplasmic reticulum damage and serum glutamate dehydrogenase (GLDH) and sorbitol dehydrogenase (SHD) as indicators of liver cytolysis. The data showed a dose‐dependent increase in GLDH and SDH serum activities (175% and 68%) from 0.05 ml kg−1; an increase in serum G6‐Pase (31%) and a decrease in microsomal G6‐Pase (38%) was apparent only after 0.5 or 1.0 ml kg−1 doses. MaCEst activity was unaffected. The results demonstrate that, under these experimental conditions, serum and subcellular measurements of MaCEst activity failed to reveal the liver toxicity of CCl4.