Phenotypic modulation of adrenal cortical cells of the rat in primary culture.

Rat adrenal cells in secondary culture have been reported to exhibit a more or less differentiated phenotype as indicated by their morphology (epithelial or fibroblastic) and their level of steroid production. Analysis of growth characteristics, delta 5-3 beta-hydroxysteroid dehydrogenase activity, and fluorogenic steroid output of adrenal cortical cells of the rat in primary culture indicates that morphology and steroid production can be quantitatively and qualitatively altered with little change in the activity of the basic steroidogenic enzyme delta 5-3 beta-hydroxysteroid dehydrogenase. These results confirm the origin from steroidogenic tissue of the adrenal cells in culture, and indicate that the changes they show in vitro are best interpreted as phenotypic modulation rather than dedifferentiation.