Neonatal androgen abolishes clock-timed gonadotrophin release in prepubertal and adult female hamsters

Area of Science:

• Reproductive Endocrinology
• Neuroendocrinology
• Developmental Biology

Background:

• Neonatal exposure to androgens can permanently alter reproductive neuroendocrine function in females.
• Understanding the timing and mechanisms of these alterations is crucial for reproductive health.

Purpose of the Study:

• To investigate the effects of early-life testosterone propionate exposure on the development of cyclic gonadotropin release in female rats.
• To determine if neonatal androgenization affects the sensitivity of gonadotropin secretion to steroid feedback.

Main Methods:

• Female rats were injected with testosterone propionate or oil within 24 hours of birth.
• Serum levels of LH, FSH, and progesterone were measured at different times of day in juvenile animals.
• Adult ovariectomized rats were tested for gonadotropin responses to estradiol implants.

Main Results:

• Controls exhibited diurnal rhythms in LH, FSH, and progesterone, which were absent in testosterone propionate-injected animals.
• Neonatal androgenization did not affect the LH and FSH surge following ovariectomy (gonadectomy response).
• Androgenized females failed to show the positive feedback surge of gonadotropins in response to estradiol implants.

Conclusions:

• Neonatal androgenization disrupts the development of normal pulsatile gonadotropin release before puberty.
• The effects of neonatal androgenization on cyclic gonadotropin release are distinct from its effects on steroid-modulated gonadotropin secretion in adulthood.