Binding pattern of 125iodine thyroxine and tri-iodothyronine in skin and liver tissues of spotted munia, Lonchura punctulata: co-relation to seasonal cycles of breeding and molting.

Prevalent notion about thyroid hormones is that thyroxine (T4) is a mere precursor and physiological effects of thyroid hormones are elicited by tri-iodothyronine (T3) after mono-deiodination of T4. Earlier studies on feather regeneration and molt done on spotted munia L. punctulata suggest that T4 (mono-deiodination suppressed by iopanoic acid and thyroidectomized birds) is more effective than T3 in inducing feather regeneration.