INSENSITIVITY OF OVARIAN MUCOPOLYSACCHARIDES TO SYSTEMIC L- AND D-THYROXINE TREATMENT

Abstract

ABSTRACT The effect of 1-thyroxine and d-thyroxine on the content of mucopolysaccharides in rabbit ovaries was studied histologically and biochemically. The doses of 1-thyroxine and d-thyroxine completely blocked the pituitary release of thyroid-stimulating hormone (TSH) as shown by the inhibition of 131I release from the thyroid gland. The treatment with 1-thyroxine as well as with d-thyroxine was continued for 15 and 30 days respectively. 1-Thyroxine brought about a loss of weight in the rabbits and caused a decrease in ovarian weight. d-Thyroxine produced no loss of weight and did not affect the ovarian weight. Neither 1-thyroxine nor d-thyroxine altered the gross appearance of the ovaries. Histological examination showed the quantity, distribution, and intensity of metachromatic substance to be identical in all experimental groups. Autoradiography showed no changes in the distribution of the 35S-containing mucopolysaccharides. Neither 1-thyroxine nor d-thyroxine altered the ovarian concentration of water or hexosamine, or the uptake of 35S-sulphate.