Alpha-fetoprotein can regulate growth in the uterus of the immature and adult ovariectomized mouse.

This is a report of development of (1) a 3-day immature mouse bioassay for alpha-fetoprotein (AFP) to increase the working range in uterine wet weights over-coming seasonality, and (2) a bioassay for AFP performed with ovariectomized adult mice to increase sensitivity. Mouse AFP was isolated from amniotic fluid and purified by polyacrylamide gel electrophoresis followed by Blue Sepharose chromatography. The uterine growth evoked by the injection of 1.0 microgram AFP together with excess molar oestradiol (0.5 microgram) over a 23-h period was compared in immature ovariectomized adult Nylar mice. The 3-day assay with immature mice was rendered usable in any season, with sensitivity comparable to the 1-day assay. Increased sensitivity, however, was demonstrated by utilization of AFP in a 1-day assay with the adult ovariectomized mouse.