THE EFFECT OF ANTERIOR HYPOPHYSEAL ADMINISTRATION ON THE OVARIES OF OLD RATS1

Following the removal of the left (control) ovaries, groups of immature, young adult and old rats received homologous anterior lobe implants daily for 10 days; the right (stimulated) ovaries were obtained at autopsy. The ovaries were examined in serial sections for the numbers and sizes of corpora lutea and follicles, and for the presence of “wheel cells” in the interstitial tissue. The ovaries of the old rats showed a variable response (increase in weight and an increase in the number and size of follicles and of corpora lutea) to anterior lobe implants, but for the group as a whole, there were statistically no significant differences between the “control” and “stimulated” ovaries for the weights of the organs or the numbers of corpora lutea, and only borderline significance for the number of follicles. However, increase in the size of the follicles and corpora lutea in the stimulated ovaries was more pronounced and the differences, as measured by the mean diameter of these structures, showed a high degree of statistical significance. Wheel cells were present in 75% of the “control” ovaries and in only 29% of the “stimulated” ovaries. The reaction of the “stimulated” ovaries of the immature and young adult rats to anterior lobe administration was much more pronounced and relatively more constant than that which occurred in the old rats.