Relationship between functional castration and alpha fetoprotein produced by hepatoma bearing female rats

In rats bearing Morris hepatoma No. 7777, serum levels of alpha fetoprotein (AFP) increased as tumor size increased. Hepatoma-bearing females remained in diestrus once the tumor exceeded a cross-sectional area of 12 cm². The following changes were seen in tumor-bearing rats compared to control animals: uterine wet weight was significantly decreased, the uterine epithelial mucosa was lower, castration cells developed in the anterior pituitary, and there was a 3- to 23-fold elevation in serum estrogen levels. The authors conclude that circulating estrogen is bound to AFP in hepatoma-bearing female rats and that in this bound state it is unable to exert its normal physiological actions.