1431868-11-9

L-Thyroxine-¹³C₉,¹⁵N is intended for use as an internal standard for the quantification of L-thyroxine by GC- or LC-MS. L-Thyroxine is a synthetic form of the thyroid hormone thyroxine. In vivo, L-thyroxine (0.9 and 2.7 μg) inhibits synthesis and release of thyrotropin induced by thyrotropin-releasing hormone from the anterior pituitary in mice. It also reverses decreases in levels of circulating thymic serum factor (FTS) and the number of T rosette-forming cells in an old age-induced mouse model of hypothyroidism. Formulations containing L-thyroxine have been used in the treatment of hypothyroidism.

Thyroxine Carboxy,α,β,1,2,3,4,5,6-13C9,15N is 13C and 15N labeled analogue of Thyroxine (T425600), which is one of the thyroid hormones involved in the maintenance of metabolic homeostasis.