Abstract
Partially purified pig thyroid gland peroxidase was inhibited by the following (in descending order of inhibition): KCN, NaN3, 3-amino-l,2,4-triazole, thiouracil, propyluracil, p-aminobenzoate, KSCN, KCIO4, NaF, thiourea. Thyroid-stimulating hormone had no effect on the peroxidase activity. Nearly identical results were obtained by using guaiacol and iodide as the oxidizable substrates. A higher concentration of H2O2 (10-3 M) was inhibitory.