Responses of the anterior pituitary of ovariectomized rats to oestradiol-17 beta administration.

The response of the female rat anterior pituitary gland to oestradiol-17 beta administered sc by silastic capsule implants (6-120 microgram/day) has been examined. Cholesterol, oestradiol-17 alpha, and testosterone were used as control hormone implants. The biochemical changes in the gland as assayed by DNA, RNA, and protein contents were monitored at intervals of 7, 21, 42, and 120 days. In addition, the number of cells per gland was determined by an experimental cell counting technique and correlated to the number of cells based on total DNA content. These results extend previous observations of the hypertrophy of the anterior pituitary and show essentially parallel increases in cell number, DNA, RNA, and protein contents.