from
The Collaborative International Dictionary of English v.0.48
Iodothyrin \I`o*do*thy"rin\, n. [Iodo- + thyro- + -in.]
(Physiol. Chem.)
A peculiar substance obtained from the thyroid gland,
containing from nine to ten per cent of iodine.
Note: 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.]
Note: It is probably an impure extract of thyroid gland,
containing thyroxine. See Merck Index 11th Ed. #9345,
the entry for thyroidin.
[PJC]