Since the work of Watson & Pearce (1949) it has been known that subnormal thyroid activity affects the glycosaminoglycans (GAG) of skin. The changes reported were an increase in the hyaluronic acid and a decrease in the dermatan sulphate content of the skin (Schiller, Slover & Dorfman, 1962; Kofoed & Bozzini, 1967). These results seem to be independent of thyrotrophin because the same changes are noted after hypophysectomy as in hypothyroidism (Schiller et al. 1962). Since hypophysectomy has a different effect on skin and tracheal cartilage GAG (Kofoed & Bozzini, 1969), experiments were done to study the distribution of these compounds in cartilage of thyroidectomized rats and to compare this with the distribution in skin.
Female Wistar rats, weighing approx. 200 g., were used throughout these experiments. Thyroid destruction was accomplished by administration of 700 μc of 131I. Six months after radioactive iodine administration, rats were divided into three