THYRO-PITUITARY RELATIONSHIPS IN CHILDREN WITH CRETINISM AND HYPOTHYROIDISM*†

Abstract

THE relationship which exists between the thyroid and pituitary has been known for a long time. Thyrotropin (TSH) production is activated in states of decreased thyroid hormone production, and anterior pituitary production of thyrotropin is inhibited by the thyroid hormone secreted. Exogenous thyroid hormone, likewise, inhibits the production of thyrotropin, resulting in decreased synthesis of endogenous thyroid hormone (1). Thus, a reciprocal relationship exists between the anterior pituitary and the thyroid gland. However, most concepts of this interaction are based on morphologic studies or, at best, on indirect physiologic evidence. There have been relatively few measurements of the levels of circulating thyrotropic hormone in humans. In 1951, D'Angelo, Paschkis, Gordon and Cantarow (2) reported observations on the thyroid-thyrotropic hormone balance of normal and endocrinopathic individuals. Data were presented on 9 adults and 1 child with hypothyroidism. The titers of thyrotropin varied widely from patient to patient; in 2 cases they were normal, in 3 cases excessively high, and in 5 cases undetectable. Levels of thyrotropin before and after treatment with desiccated thyroid were reported for 4 of these patients.In 2 of them there was amelioration of clinical symptoms without restoration of normal hormonal balance. The present communication presents additional data on 5 hypothyroid (cretinous) and 3 euthyroid infants and children.