ALTHOUGH the influence of low environmental temperature on the functional activity of the thyroid gland has engaged the attention of many investigators, in only a few studies has the interplay of the pituitarythyroid system in cold exposed animals been assessed by functional criteria in both glands. Activation of the thyroid gland by cold is prevented by hypophysectomy and survival of hypophysectomized animals in the cold is generally poor (Wolf and Greep, 1937, Brolin, 1946). Increase in thyrotrophic (TSH) hormone activity of the pituitaries of rats kept at low environmental temperatures was demonstrated by Kuschinsky (1935) who related this change to the thyroid activation observed after cold exposure. In a noteworthy contribution Brolin (1946) correlated hyperplastic changes in the thyroid with hypertrophy and vacuolization of the anterior pituitary basophils and with heightened TSH levels in the body fluids of cold-exposed rats. The exact mechanism by which the pituitary-thyroid system is activated under conditions of low environmental temperature has not been elucidated.
No takes yet. Share an insight, caveat, or question.
Stevens et al. (1955) studied this question.