Abstract
We investigated the role of thyroxine on bone growth in energy deficient rats. Rats were fed a normal diet and injected with saline, or a low-energy diet and injected with saline or 0.1, 1, or 5μg/100g BW of thyroxine for 22 days. Thyroxine injections decreased body weight gain but did not affect bone length and width. The epiphyseal growth plate was thinner and the activities of bone alkaline and acid phosphatase in energy deficient and 5μg/100g BW thyroxine injected animals were lower than that of the other treatment groups. Serum total thyroxine and triiodothyronine concentrations were increased but somatomedin C concentration was decreased by injecting with 5μg/100g BW of thyroxine in energy deficient rats.
