ROLE OF THE THYROID AND ANTERIOR PITUITARY GLANDS IN THE MAINTENANCE OF THE HARDERIAN GLANDS OF THE RAT

Abstract

The Harderian gland-body weight ratio in the rat decreases with age. Weight of the Harderian gland is not changed by adrenalectomy, castration, or stress (fracture), nor is it changed by treatment with ACTH, cortisone, estradiol or testosterone. Following either thyroidectomy or hypophysectomy, the Harderian glands of the growth rat atrophy and do not grow appreciably thereafter. The atrophy and growth failure following hypophysectomy can be prevented by giving pituitary fractions containing growth hormone and thyroid stimulating hormone (TSH) partially prevented with a large dose of thyroxin but not with a maintenance dose of thyroxin. Atrophy and growth failure following thyroidectomy can be prevented by maintenance doses of thyroxin, but not with mixtures of anterior pituitary hormones. It is suggested that normal maintenance of the Harderian glands in the rat depends upon the presence of thyroid hormone and an anterior pituitary factor trophic to the Harderian glands, possibly growth hormone.