A Study on the Interaction of the Thyrotropin-Releasing Factor and L-Triiodothyronine: Effects of Puromycin and Cycloheximide

Abstract

Interaction between thyrotropinreleasing factor (TRF) and L-triiodothyronine (T3), which controls the release of thyrotropin (TSH) from the anterior pituitary gland, has been studied in mice with the use of inhibitors of protein synthesis, puromycin and cycloheximide. Neither puromycin nor cycloheximide altered the increase in release of TSH which follows the administration of TRF. On the other hand, eachof these agents prevented the inhibition of the TRF-TSH release response by T3. A special characteristic of the effects of puromycin and cycloheximide on the T3 block is that larger amounts of T3 overcame the effects of these inhibitors of protein synthesis. A hypothesis is presented on the mechanism by which TRF and the thyroid hormones regulate TSH secretion.(Endocrinology82: 75, 1968)