Effects of dexamethasone treatment on iodothyronine deiodinase activities and on metamorphosis-related morphological changes in the axolotl (Ambystoma mexicanum).

In amphibians, there is a close interaction between the interrenal and the thyroidal axes. Hypothalamic corticotropin-releasing hormone or related peptides stimulate thyroidal activity by increasing thyrotropin synthesis and release, while corticosterone accelerates both spontaneous and thyroid hormone-induced metamorphosis. One of the mechanisms that is thought to contribute to this acceleration is a corticosterone-induced change in peripheral deiodinating activity.