The in vivo effect of mirex on soluble hepatic enzymes in the rat

Adult male and female rats fed dietary mirex in concentrations of 10, 20, 30, 40, and 50 ppm for 4 weeks exhibited significant decreases in liver levels of lactic dehydrogenase, malic dehydrogenase, sorbitol dehydrogenase, glutamic oxaloacetic transaminase, and glutamic pyruvic transaminase as compared to control levels. Enzyme losses were cytoplasmic and decreased in magnitude with increased time of exposure and dietary mirex concentrations. Serum sorbitol dehydrogenase levels were increased above control levels during the first week of mirex exposure while hepatic sorbitol dehydrogenase levels were concomitantly decreased below the control levels. Hepatic glutamic oxaloacetic transaminase levels were significantly decreased during the first week for all dietary mirex concentrations as were the other enzymes at the 40 and 50 ppm mirex concentrations. The magnitude of the enzyme decreases in female rat tissue was consistently lower than enzyme decreases in the male rat tissue fed equivalent dietary mirex dosages. Liver weights for male rats increased significantly at all dietary mirex levels during week one. However, only animals receiving the 40 and 50 ppm dietary mirex levels showed significant liver weight increases at the end of week 4. Female rat liver weights were increased at the 30 and 40 ppm mirex dietary levels after 4 weeks. No significant differences in body weights were observed for any dietary level of mirex. Mirex hepatic residues appeared to be equal for both sexes. No gross histological alterations were observed following treatment.