Age-related changes in gonadotropin, prolactin and growth hormone levels with reference to the development of uterine adenomyosis in female SHN mice.

The patterns of serum FSH, LH, PRL and GH levels in SHN mice were determined by radioimmunoassay between 1 and 12 months of age. In addition, the incidence of spontaneous development of uterine adenomyosis and mammary tumor was also studied for 12 months. Serum FSH level increased gradually with age while the level of LH was almost constant during the observation period. On the other hand, concentrations of PRL and GH significantly increased with age. The present data showed that the development of adenomyosis and mammary tumor rapidly increased after 6 and 9 months of age, respectively. Pituitary grafting at 30 days of age resulted in a high incidence of adenomyosis after 6 months of age. There were no significant differences in FSH and LH levels between mice with and without pituitary grafting. However, pituitary grafting resulted in the increase in PRL and GH levels compared with age-matched controls. These findings altogether suggest that the spontaneous development of adenomyosis in SHN mice may be related to the elevation in PRL and GH levels as a function of age.