Age-related decline in receptivity in normal, neonatally androgenized female and male hamsters.

The pattern of female sexual behavior shown by aging male and female hamsters was related to exposure to perinatal androgen. Twenty-five female and 37 male hamsters in Experiment 1 was gonadectomized on the day of birth or at 43 days of age. The received 11 tests for receptivity between the ages of 28 and 66 wk. In Experiment 2, 83 females were implanted with a Silastic pellet containing 3, 1, 3 or 9% testosterone (T) or testosterone propionate (TP) by weight from the second to the tenth day of life, and tested approximately every 2 wk from 22 to 58 wk of age. Receptivity was induced by estradiol benzoate and progesterone injected before each 600 sec mating test. Normal females exhibited the highest lordosis scores, followed by minimally androgenized females and males castrated at birth. High doses of exogenous or endogenous perinatal T suppressed receptivity throughout the animal's lifespan, but did not accelerate the rate of decline in female behavior over time. Non-androgenized animals showed the greatest decrease in receptivity with advanced age.