Dose-response effects of tri-iodothyroacetic acid (Triac) and other thyroid hormone analogues on glucocorticoid-induced skin atrophy in the haired mouse.

Thyroid hormones have an influence on the connective tissue biology of the skin and, theoretically, topically applied thyroid hormones or hormone analogues could have a stimulatory effect on collagen synthesis. In this investigation the effect of topical tri-iodothyroacetic acid (Triac) and other thyroid hormone analogues were tested for their effect in preventing betamethasone-induced skin atrophy in the normal haired mouse. Triac, tri-iodoproprionic acid (Triprop) and the synthetically developed thyroid hormone analogue KB-026 and 2 different Triac cream formulations were applied along with betamethasone on shaved mouse skin. Triac in daily doses of 1 nmol/cm2 and higher was able to block the betamethasone-induced skin atrophy in mice skin. In high doses, Triprop and KB-026 also had a blocking effect. Triac alone had a stimulatory effect on dermal thickness. This study indicates that thyroid hormone analogues may be used to prevent corticosteroid-induced skin atrophy.