Harderian Gland: Regulation of Sexual “Type” by Gonads and Pineal Gland

Abstract

The sexual dimorphism of the Harderian glands of golden hamsters is regulated by a complex interaction of the gonads and pineal gland. Ovariectomy prevented the conversion to male-type gland which normally follows blinding. Testosterone administration in combination with blinding and ovariectomy promoted the male type. Ovariectomy after 8 wk of blinding was ineffective in reversing the effects of blinding on the Harderian glands, but ovariectomy and pinealectomy caused complete reconversion to the female type. This apparently is the 1st report to demonstrate an influence of the ovaries on the Harderian gland of the hamster. In males, administration of testosterone for 7 days after 8 wk of castration had little effect on the conversion to the female type which normally attends castration, whereas testosterone injection followed by a period of blinding completely reversed the effects of castration on the Harderian gland. The male-type Harderian gland evidently is expressed whenever significant androgen levels are present, or when the glands are exposed to androgen priming during or just prior to a period of blinding-induced pineal activation. The probable role of ovarian androgens in mediating conversion to the male-type gland is discussed.