Role of thyroid and testicular hormones in the regulation of basal metabolic rate, gonad development, and body weight of spotted munia, Lonchura punctulata.
Normal saline, L-thyroxine (L-T4, 0.5 micrograms/bird/day), and testosterone (100 micrograms/bird/day) were administered separately to intact, thyroidectomized, and castrated spotted munia over a 30-day period and the effects on basal metabolic rate (BMR), gonads, and body weight were recorded. Thyroidectomy and castration decreased the BMR. L-Thyroxine increased the BMR of intact and thyroidectomized but not of the castrated birds. Testosterone had no effect on BMR of either the intact or of the operated birds. L-Thyroxine and testosterone both had no effect on regressing gonads but inhibited thyroidectomy-induced testicular development. Body weight increased in intact, testosterone-treated birds, and in thyroidectomized and castrated spotted munia. L-Thyroxine inhibited body weight gain only in thyroidectomized birds. It is suggested that the physiological actions of L-T4 and testosterone depend on the gonadal status, thyroid activity, and nature of the thyroid-gonad relationship.
D000818:Animals; D001481:Basal Metabolism; D001717:Birds / Q000502:physiology*; D001835:Body Weight; D002369:Castration; D006066:Gonads / Q000254:growth & development*; D008297:Male; D013739:Testosterone / Q000502:physiology*; D013961:Thyroid Gland / Q000502:physiology*; D013965:Thyroidectomy; D013974:Thyroxine / Q000502:physiology
D013739:Testosterone; D013974:Thyroxine