Amino Acid C14Incorporation Into Protein by Thyroid Gland Slices: Effects of Thyrotropic Hormone Injections and of Hypophysectomy

Abstract

Surviving slices of thyroid glands of guinea pigs incorporated the C¹⁴ of uniformly labeled l-leucine, l-valine, l-tyrosine, l-arginine, l-aspartic acid, l-phenylalanine and l-proline into proteins. Under identical incubation conditions, the incorporation of the C¹⁴ of the C¹⁴-leucine into proteins by the thyroid gland slices exceeded that observed with liver slices and diaphragm. The injection of thyrotropic hormone into normal guinea pigs increased the recoveries of the C¹⁴-protein in experiments with all 7 labeled amino acids. Hypophysectomy in rats reduced the incorporation of leucine C¹⁴ into proteins by slices prepared from their thyroid glands. Injections of thyrotropic hormone corrected this defect in the hypophysectomized rat.