EFFECT OF THYROTROPIN ON THE PATTERN OF THYROID HORMONES IN PLASMA*

THE data of some investigators would indicate that physical and emotional stress may influence various parameters of thyroid activity (1–6). The relatively prolonged latent period that precedes a demonstrable effect of thyroxine in both the experimental animal and man (7–11) has detracted attention from the role of the thyroid gland in the immediate metabolic response of the body to stress. As a result of the demonstration of the potent and rapidly acting thyroid hormone, 3:5:3′-l-triiodothyronine, in the serum of man and animals (12, 13), however, it seemed possible that this substance could serve as a so-called emergency-type hormone if it were elaborated in increased amounts in response to an acutely stressful situation. The functional relationship between the central nervous system, the anterior pituitary and the thyroid gland (2, 14, 15) suggests that such participation of the thyroid might be mediated through fluctuations in the secretion of thyrotropin. Because of these considerations, paper radiochromatographic techniques have been utilized to characterize the early changes in the pattern of iodinated compounds in plasma associated with the increase in the concentration of serum protein-bound iodine that follows the administration of thyrotropin to euthyroid and hyperthyroid individuals.