Influences of Protein Synthesis Inhibitors on TRH-Stimulated Secretion of Glycosylated TSH

This is the authors' abstract. We don't add key points for this paper.

The significant influence of protein synthesis inhibitors on TRH-stimulated secretion of glycosylated TSH was investigated in the rat anterior pituitary in vitro. TRH stimulated secretion of (3H)glucosamine-labeled TSH but did not change incorporation of its labeled precursor into the pituitary TSH. Addition of cycloheximide significantly inhibited both incorporation of (14C)alanine into the pituitary protein and of (3H)glucosamine into the pituitary TSH even 3 hours after incubation, while it did not cause a significant change in secretion of glucosamine-labeled TSH. Apparent inhibition of (14C)alanine incorporation into the pituitary protein was produced by addition of actinomycin D in the 3 and 6 hour-incubation, but the same drug did not cause the significant change in the amount of (3H)-glucosamine-labeled TSH in the anterior pituitary and medium. It is concluded from the present study that TRH plays a potential role in regulating carbohydrate synthesis of TSH prior to secretion, and messenger RNA is not essential for its role in the glycosylation of TSH.