Partial hepatectomy of marmoset: Clinical and pathological effects and utility in microsomal enzyme analysis

Liver biopsy based on a partial hepatectomy technique (shearing) was perfor med in 10 common marmosets (Callithrix jacchus). This is a preliminary stud y to evaluate the effects of drugs on hepatic microsomal enzymes: cytochrom e P-450 and T-4 uridine diphosphate glucuronyl transferase (T-4-UDPGT), by comparing post-treatment values with pre-treatment values individually with a limited number of animals. The effects of the biopsy on clinical finding s and liver pathology were evaluated during the first 5 post-surgical weeks . Although the plasma aspartate aminotransferase (AST) activities tended to decrease from 1 to 4 weeks post-surgery, no abnormality was noted in clini cal sign, body weight, the hematocrit value or other blood chemical values. At necropsy, adhesion of the sheared site of the liver to the parietal per itoneum or the small intestine was evident in 2 of the 4 marmosets. Microsc opic examination revealed focal fibrosis in the liver, but if was localized around the sheared site. Based on the above results, it was concluded that liver biopsy must be performed more than one month before administration o f the drug to be tested. The biopsy samples and the whole liver samples obt ained at autopsy were subjected to analysis of microsomal protein content, cytochrome P-450 content and T-4-UDPGT activity. In comparison with the val ues from the whole liver samples, those from the biopsy samples showed no s ignificant difference. Furthermore, there was a significant correlation rat her than difference between matched values. This suggested that partial hep atectomy is a useful method for obtaining pretreatment values in liver bioc hemistry to evaluate the effects of drug-treatment in individual animals.