THE ACTION OF THYROID HORMONES ON THE OXYGEN CONSUMPTION AND RESISTANCE TO COLD OF ADRENALECTOMIZED AND THYROIDECTOMIZED-ADRENALECTOMIZED MICE

Abstract

SUMMARY The effect of thyroid medication on the oxygen uptake and resistance to cold of normal, adrenalectomized (adx) and thyroidectomized-adrenalectomized (thyx-adx) mice was studied. All adx animals were maintained on salt. 1. 3–12 mg dried thyroid gland or 2·5 μg l-thyroxine, given daily for 7 days, prolonged the survival times of adx and thyx-adx mice in cold. 24 mg, however, decreased survival time. 2. 3–6 mg dried thyroid gland given daily for 6 days raised the oxygen uptake of both normal and thyroidectomized (thyx) but not of adx mice. 3. 10 μg l-thyroxine given daily for 14 days increased the oxygen uptake of adx mice, but 40 μg failed to do so in mice which were also thyx.