Comparative Effects of TSH and of Insulin on Fetal Rat Thyroid Gland Maintained in Organ Culture

Abstract

Summary

In organ culture of fetal rat thyroid glands, both insulin and TSH enhance significantly the 24 hr incorporation of ¹²⁵I into protein-bound iodotyrosines and iodothyronines; however, TSH is much more active than insulin. Under the same experimental conditions, although insulin is not so effective as TSH, these two hormones stimulate, in a similar fashion, the iodination of soluble proteins. Both TSH and insulin enhance also the biosynthesis of ribosomal RNAs and of nuclear DNA-like RNAs.

The technical assistance of Mrs. Jennequin-Gerbod is gratefully acknowledged.