Effect of dexamethasone on the neonatal adrenal medulla.

Newborn male rats were injected with a single dose of dexamethasone on the first day of life. Controls received only the diluent. Two to ten days later the experimental and control animals were sacrificed, and the adrenal medullae were processed for electron microscopy and for histochemical demonstration of catecholamines. Rats that received dexamethasone, as compared to controls showed (1) an earlier appearance of the catecholamine reactions, and (2) a pronounced development of Golgi complex. These results are further indication that glucocorticoid stimulates the maturation of the chromaffin complex. The Golgi apparatus may play some role in this inductive mechanism.