THE EFFECT OF HYPOPHYSECTOMY, AND OF INJECTIONS OF THYROTROPHIN AND CORTICOTROPHIN INTO HYPOPHYSECTOMIZED ANIMALS, ON THE SLOUGHING CYCLE OF THE LIZARD, GEKKO GECKO L.

Abstract

SUMMARY Hypophysectomy resulted in a lengthening of the sloughing cycle for about 25 days as compared with the normal cycle. The increase is only in the resting phase, the renewal phase remains unaffected. Thyroid-stimulating hormone did not affect the epidermis directly but increased the activity of the thyroid gland in the hypophysectomized geckos as judged by the uptake of 131I and follicular cell height, and reduced the resting phase by about 7 days. Corticotrophin inhibited sloughing for at least 65 days, and possibly entirely, with the epidermis remaining in the resting condition.