Distinct transcriptional profiles in rat thyroid glands after developmental exposure to three in vitro thyroperoxidase inhibiting chemicals

Thyroperoxidase (TPO) is a key enzyme in thyroid hormone (TH) synthesis in the thyroid gland. TPO inhibition can thus disrupt the TH system and cause deleterious effects associated with hypothyroidism. Many industrial chemicals can inhibit TPO activity in vitro, but it remains unclear how this manifest in the thyroid gland at the molecular level during development. Here, we characterized the transcriptome of rat thyroid glands developmentally exposed to either of three in vitro TPO-inhibitors including amitrole, 2-mercaptobenzimidazole (MBI) and cyanamide. Pregnant Sprague-Dawley rat dams were exposed to 10 mg/kg bw/day MBI, 50 mg/kg bw/day amitrole or 15/11.25 mg/kg bw/day cyanamide from gestation day 7 to postnatal day 16. BRB-seq was performed on thyroid glands from 16-days old male pups (n = 7-8, max 2 pups from each of 4 litters).