Iodothyrin

n. [ Iodo- + thyro- + -in. ] (Physiol. Chem.) A peculiar substance obtained from the thyroid gland, containing from nine to ten per cent of iodine.

☞ It is a very stable compound, and is believed to be active principle in thyroid extracts and in the internal secretion of the thyroid gland. It was originally called thyroiodin. [ Webster 1913 Suppl. ]

☞ It is probably an impure extract of thyroid gland, containing thyroxine. See Merck Index 11th Ed. #9345, the entry for thyroidin. [ PJC ]