[Changes in free and total thyroid hormones and reverse T3 in adult male rats during fasting]

The serum levels of thyroid hormones (T3, F.T3, RT3, T4 and F.T4), cholesterol and triglycerides were measured in a population of adult male rats subjected to experimental fasting. Comparison of bindings with results published in the literature reveals certain disagreements attributable to individual variations in the animals resulting from physical or physiological factors. This study demonstrates that deiodination of thyroxine in T3-Reverse has an economic role on a metabolic level. Evaluation of the T3/RT3 ratio appears to provide an indication of the homogeneity of the peripheral metabolism in an experimental population.