METABOLIC EFFECTS OF THYROXINE INJECTED INTO NORMAL, THIOURACIL-TREATED AND THYROIDECTOMIZED RATS1

Abstract
The thyroidectomized rat gives a metabolic response to a daily injn. of 6 [mu]g-of DL-thyroxin/kg. of body wt., an amt. inadequate to produce any increase in the oxygen consumption of normal or thiouracil-treated animals. The decreased metabolic rate of thyroidectomized rats is returned nearly to normal by 12 [mu]g- DL-thyroxine/kg./day. A chronic mammalian prepn. of high sensitivity is thus made available for many aspects of thyroid study.