The response of the sebaceous glands of female rats ovariectomized at birth to testosterone.

Abstract

Newborn Sprague-Dawley rats were ovariectomized within 24 h of birth and control animals were sham-operated. Immediately, one-half of the rats in each group received a single injection of 500 micrograms testosterone propionate. The other half acted as a vehicle control. Normal male and female rats were also included for comparison. The secretion rate of sebum was measured at the age of 80 days from the amount of skin-surface lipids that could be extracted with acetone and which had been produced during 2 days. Male rats secreted more sebum than female rats. In female rats, irrespective the presence or absence of ovaries, when treated with a single injection of testosterone propionate at birth, although secreted significantly more sebum than vehicle control groups, the increase was still far below the level normally found in the male. On the other hand, implantation of testosterone pellet at the age of 4 weeks in neonatally ovariectomized-androgenized female rats greatly increased sebum secretion to an extent far exceeding that of the normal male rats. It is concluded that testosterone can directly increase sebum secretion in the female rats irrespective the presence or absence of ovaries when given at birth and reinforcement at about puberty produces a full effect of secretion.