Mammalian ovary development undergoes important changes during the perinatal period, moment when follicles are assembled and start to develop in a process not well known, involving endocrine and paracrine factors. In order to investigate the effect of two different hormonal environments on the early development of the ovary, we used an autologous transplant model in which Syrian hamster fetal ovaries were grafted under the kidney capsule of males hosts previously unilaterally or bilaterally orchidectomized. After 35 days of graft, ovaries and kidney parenchyme of the host male did not present signs of rejection. Ovaries contained primordial, primary follicles, secondary follicles and few tertiary follicles with morphological features similar to ovaries of control females of 35 days of age. Healthy primary and secondary follicles of experimental groups had frequency distribution and size similar to control ovaries but tertiary follicles were scarce in control as well as in grafts where they were mainly atretic. PCNA, marker of proliferation, was immuno detected in granulosa cells of growing follicles and the marker of apoptosis, Caspase 3 active, was evident mainly in secondary follicles. Immunoreactivity for steroidogenic proteins, StAR, 3-βHSD and aromatase detected in the follicular wall cells and the decreased serum levels of FSH without important changes in testosterone in bilateral orchidectomized males that received ovarian graft, and testosterone decreased without changes in FSH levels in unilateral orchidectomized males (UO) with ovarian graft, all together suggest the effect of steroid hormones produced by the ovary. In conclusion, the experimental model of autologous transplant presents evidence of early ovary development under the kidney capsule and its functional integration to the endocrine axis of the host male.
KEY WORDS: Ovary; Folliculogenesis; Steroidogenesis; Ovarian graft; Hamster.