Alpha-fetoprotein dynamics during ethionine-induced hepatocarcinogenesis in rat

Rats fed on a diet containing 0.25% DL-ethionine (ethionine), which has been usually used as carcinogenic dose, demonstrated the early elevations of serum alpha-fetoprotein (AFP) approximately in week 6 of the feedings. After declining once between week 10 and 14, the serum AFP levels increased again in week 22 of the continuous feeding, when well differentiated hepatocellular carcinoma had already developed. The level of serum AFP after development of hepatoma was found to be lower than those seen during the early elevation of AFP. Furthermore, in ethionine-induced hepatoma-bearing rats, AFP levels in the tumors were rather low as compared to those in the nontumorous portions of the liver surrounding the tumors. The results indicated that ethionine-induced hepatocellular carcinoma is not an AFP-highly-producing tumor.