INFLUENCE OF VARIATION IN ENVIRONMENTAL TEMPERATURE AND THYROID STATUS ON GROWTH AND FEED CONSUMPTION OF THE MALE MOUSE

Publisher Website
Google Scholar
Abstract
The results obtained in the expts. here reported indicate that mild hyperthyroidism stimulates while hypothyroidism depresses body wt. gains in the growing male mouse at environmental temps. of both 24[degree] and 30[degree]C. Thyroprotein when fed to growing male mice for a period of 4 wks. at 24[degree]C as 0.025 and 0.05% of the ration caused highly significant increases in the body wt. gains when compared with the control group. Control mice gained less at 30[degree] than at 24[degree]C. Mice fed 0.005% thyroprotein for 4 wks. at 30[degree]C gained significantly more wt. than the control group at 30[degree]C and slightly, but not significantly, more than the controls at 24[degree]C. Both food and water consumption were depressed by either thiouracil feeding or elevation of the environmental temp. to 30[degree]C. In mice fed graded amts. of thyroprotein, at both 24[degree] and 30[degree]C, the food and water intake increased proportionately with the thyroprotein dosage. An increase of only 6[degree]C, i.e., from 24[degree] to 30[degree]C, in environmental temp., caused a 10-fold reduction in the optimal thyroprotein dosage in young male mice. Within a narrowly limited dosage range, anabolic effects can still be observed at the higher temp. It is suggested that under these exptl. conditions the tolerance limits for thyroid stimulation are detd. principally by the temp. -regulating capacity.