THE EFFECT OF HYPOPHYSECTOMY ON AGE CHANGES IN THE OVARIES OF MICE

Abstract

SUMMARY Hypophysectomy in the mouse (A, CBA, RIII and RIII × CBA strains) significantly retards, but does not wholly prevent, the normal progressive loss of oocytes from the ovary. The proportion of follicles judged to be normal on histological criteria rises from levels of 50–60% to levels of 60–75%. CBA strain mice which normally lose oocytes faster than the other strains still show this difference after hypophysectomy. The extent to which the ovaries of hypophysectomized mice retain their normal function after more than 300 days in a gonadotrophin-free environment has been tested by transplanting them orthotopically into normal female hosts. In all cases, the grafts responded to gonadotrophin supplied by the new host and in the favourable environment provided by a young host produced normal litters as satisfactorily as transplanted normal ovaries.