Effect of Estrogenic Substance on Experimentally Hyperthyroid Male Rats1

THE AUTHOR has investigated the thyroid-ovarian relationship in rats as measured by means of basal metabolic changes. Estrogenic substance, estrone, stilbestrol and estradiol were effective in the production of a decrease in the oxygen consumption of intact or ovariectomized animals made experimentally hyperthyroid as shown by Sherwood et al. (1–5). The present investigation was undertaken for the purpose of producing a similar picture in the male rat and to determine whether sex need be considered in the use of estrogen therapy in hyperthyroidism. The details of feeding, temperature control, fasting period and time of day, which have been found essential for consistent results in the determination of basal metabolism (1), were observed in the present investigation. All animals were 8 months old at the beginning of the experimental period. Twenty-seven male rats were used throughout the experiment.