SEX STEROIDS MODULATE NADPH-DIAPHORASE EXPRESSION IN THE POSTNATAL ADRENAL NEURONS OF THE RAT

The rat adrenal gland contains nitric oxide-producing ganglion cells, contributing to its innervation. In a previous study postnatal number and morphology of these adrenal neurons were analyzed by NADPH-diaphor ase histochemistry in the two sexes, A transient sex-related differenc e in the number of NADPH-diaphorase positive neurons per adrenal gland was found at postnatal day 10, when the number of stained neurons in males was nearly twice that found in females, In the present work we s tudied the effects of perinatal hormonal manipulation on the number of adrenal NADPH-diaphorase-positive neurons during the second postnatal week, The number of labeled adrenal neurons at postnatal day 10 was h igher in females receiving perinatal androgen treatment than in contro l untreated females, and was similar to that of control untreated male s, In contrast, in males that underwent perinatal deprivation of testo sterone the number of labeled adrenal neurons was lower than in contro l males, and similar to that of control females, These differences wer e found in both the adrenal cortex and medulla. In males and in testos terone-treated females there was a higher proportion of stained multip olar neurons than in females and in androgen-deprived males. No interg roup differences were found in the size of stained neurons, Thus, we d emonstrated that the postnatal difference in the number of NADPH-diaph orase-positive adrenal neurons in the two sexes is related to the epig enetic action of gonadal hormones during perinatal maturation. (C) 199 7 Elsevier Science Inc.