Abstract
The femora from 9-day old chick embryos were cultivated for 4 days by the roller-tube method in 35S-labeled natural medium, consisting of 1 volume of chick embryo extract, 5 volumes of horse serum and 4 volumes of balanced salt solution to permit physiologic ossification and chondrification of the bones. By measuring radiosulfate uptake, sex steroids were examined for their effects on the chondroitin sulfate synthesis of the cartilagenous bones growing in vitro. With increasing concentration in the medium testosterone and 19-nortestosterone stimulated the 35S-sulfate incorporating activity per unit dry weight increase of the bones, while the reverse was the case with estradiol and progesterone. However, dehydroepiandrosterone exerted no appreciable effect.
