title: Evaluation of liver weight changes following repeated administration of carbon tetrachloride in rats and body-liver weight relationship.
abstract: The proper method of evaluating liver weight changes resulting from the primary toxic effect of a chemical was studied. We used a pair-feeding method with carbon tetrachloride (CCl4), a chemical known to cause an increase in liver weight. Male rats were assigned to an untreated control group, CCl4-treated groups (daily dose of 10 microliter or 50 microliter of CCl4 in olive oil/100 g body wt), olive oil-treated plus feed-restricted groups, and feed-restricted groups. In the 2 types of feed-restricted groups the body weight changes of the CCl4-treated groups were duplicated by imposing restrictions on feeding. Absolute and relative liver weights were compared among the 4 types of groups after treatment for 14 or 25 days. Either absolute or relative liver weight of the treated group when compared to that of the feed-restricted group was the most reliable and sensitive toxicity indicator. In comparing the treated group with the untreated control group, relative liver weight was a more sensitive toxicity indicator than absolute liver weight. However, when liver weight data for about 200 normal male rats were plotted against body weight, and the 95% confidence limits of the regression line (y = ax) were estimated, most of the data for the feed-restricted rats were outside the lower confidence limit. This means that a comparison of the relative liver weights of the treated rats and untreated control rats is not strictly valid, because the body weight-liver weight relationships are not the same in the 2 groups.
mesh_terms: D000284:Administration, Oral; D000818:Animals; D001835:Body Weight / Q000187:drug effects*; D002251:Carbon Tetrachloride / Q000633:toxicity*; D008099:Liver / Q000187:drug effects*; D008297:Male; D009929:Organ Size / Q000187:drug effects; D051381:Rats; D011919:Rats, Inbred Strains
chemical_list: D002251:Carbon Tetrachloride