The particular traits of carcinogenesis induced in Wistar rats by aflatoxin B1. III. Porphyrins and the activity of gamma-glutamyltranspeptidase in primary hepatomas and in their tissue of origin.

Inbred Wistar rats were fed aflatoxin B1 (AFB1) during a period of 15 weeks. Some of the rats were sacrificed successively at different time intervals, and the remaining animals died a natural death. Beginning with the day of AFB1 treatment termination multifocal hepatomas appeared on the 265th day in males and on the 296th day in females. The progress of AFB1 carcinogenesis was accompanied by an ever increasing disorder of porphyrin metabolism. The content of the porphyrin fractions in primary hepatomas was greater than in the tissue of origin. Serum and hepatic GGTP activity increased with the advancement of hepatocarcinogenesis and paralleled the increase of tumor weight. The GGTP activity in hepatoma reached values exceeding those in their host liver.