Orthotopic ovarian transplantation in young and aged CBA mice

Reproductive and hormonal changes associated with CBA mice which were orthotopically transplanted with ovaries from young or aged CBA mice were studied. Reproductive decline was defined by the number of mice mating and the number of implantation sites and resorptions in pregnant mice. A high percentage of resorptions was observed in aged mice receiving ovaries from young mice. An increase in the number of resorptions and a decrease in the number of implantation sites was observed in young mice transplanted with aged ovaries. Concentrations of LH, FSH and Prl were analyzed by radioimmunoassay from plasma of pregnant and nonpregnant transplanted mice, ovariectomized and sham-operated controls. Young ovariectomized mice had elevated concentrations of LH and FSH when compared to sham-operated controls. No differences were noted between the aged ovariectomized mice although the gonadotrophin levels in these animals were higher than those in comparable young groups. The highest LH and lowest FSH concentrations were found in young to young transplanted mice. The Prl concentrations in transplanted mice did not vary between groups. These data suggest that the hypothalamic-hypophyseal complex is functioning adequately in all transplanted groups and age-related changes in the ovary and uterus are responsible for embryonic mortality.