What's bred in bone: effects of thyroid hormone supplementation on bone growth and remodelling in ectotherms and endotherms. Influence of resting metabolic rate (RMR) and exercise activity on bone microstructure is investigated in a variety of amniote taxa. By varying the dose of supplemental triiodothyronine (T3), ectotherms are made hyperthyroid with elevated RMR, and endotherms - hypothyroid with depressed RMR. Effects of T3 are compared against those of mechanical loading, in form of increa ....What's bred in bone: effects of thyroid hormone supplementation on bone growth and remodelling in ectotherms and endotherms. Influence of resting metabolic rate (RMR) and exercise activity on bone microstructure is investigated in a variety of amniote taxa. By varying the dose of supplemental triiodothyronine (T3), ectotherms are made hyperthyroid with elevated RMR, and endotherms - hypothyroid with depressed RMR. Effects of T3 are compared against those of mechanical loading, in form of increased daily treadmill exercise. Rates of bone growth and secondary remodelling are determined by histological analysis, and correlated with T3 and bone strain levels. The study tests the hypothesis that evolution of endothermy can be inferred from bone microstructure of fossil bones.Read moreRead less