THE EFFECT OF GOITROGENIC AND OTHER REDUCING AGENTS ON INACTIVATED THYROTROPIC HORMONE EXTRACT1

Abstract

IN A PREVIOUS paper (Albert et al., 1946) we have shown that treatment of a thyroid stimulating hormone (TSH) extract with elementary iodine resulted in precipitation of most of the proteins of the extract. The brown iodinated precipitate was observed to have lost 95 to 100 per cent of its original thyrotropic activity. When the precipitate was triturated in an excess of acetone, 60 per cent of the iodine was removed, leaving a buff-colored protein residue containing the original thyrotropic potency. The conversion of inactivated hormonal material to activity has been accomplished in other ways. When the iodinated TSH extract precipitate was triturated with solutions of 2-thiouracil, 6-N-propyl thiouracil, aminothiazole, 5-amino-2-mercaptothiadiazole (T.C. 68), 3-phenylaminomethyl-2-mercaptothiazoline (T.C. 105) and potassium thiocyanate the precipitate immediately dissolved yielding a water clear solution containing in varying degree the original thyrotropic action.