Intranuclear inclusions in mammotrophs of the Mongolian gerbil: effect of low doses of estradiol benzoate and a study of females before weaning.

The effect of dose of estrogen on induction of intranuclear inclusions was studied in mammotrophs of the Mongolian gerbil. The number of inclusions per high power field increased significantly with 0-5 and 1-0 mug/day of estradiol benzoate but not with the 0-05 mug dose. A form of inclusion was seen in young female gerbils before weaning which suggests that inclusions arise from the cytoplasm. Intranuclear inclusions develop soon after weaning of gerbils (0-06 +/- 0-01 vs. 0-19 +/- 0-03 for young mature females).