THE IMPORTANCE OF THE THYROID IN MAINTAINING AN ADEQUATE PRODUCTION OF HEAT DURING EXPOSURE TO COLD

Abstract

Prolonged exposure to cold stimulates the thyroid gland and produces a small increase (10 or 15%) in basal metabolism. This increase appears unimportant at a time when the catabolic requirements of the animal living in the cold may be 3 times normal. Since it is known that the thyroid is essential for proper adjustments during prolonged exposure to cold, one wonders whether this gland may not increase the heat production caused by shivering or adrenine secretion. The calorigenic response to epinephrine is potentiated by injecting thyroxin or by stimulating thyroid secretion by cold. Furthermore, the maximal heat production possible during exposure to cold is increased by giving thyroxin and diminished after thyroidectomy.