Stress induces zinc finger immediate early genes in the rat adrenal gland

The secretion of steroid hormones from the adrenal cortex as well as cathec olamines from the adrenal medulla is stimulated by stress. In this study, w e studied the effect of capsaicin-induced stress on the expression of the i mmediate-early genes (IEGs) NGFI-A, -B, -C, egr-2, -3 and Nurr1 in the rat adrenal gland using in situ hybridization. All of these IEGs except egr-2 w ere rapidly induced in the adrenal cortex and medulla. The temporal pattern s of the IEG induction in medulla varied significantly. NGFI-A was induced in medulla within 15 min after stress, NGFI-B, egr-3 and Nurr1 were induced by 30 min, whereas NGFI-C was induced by 2 h. Surprisingly, only NGFI-B an d Nurr1 were induced in the glucocorticoid secreting regions of zonae retic ularis and fasciculata of the cortex, starting 15 min after the stress. All of the inducible IEGs were induced in the aldosterone secreting zona glome rulosa 15-30 min after the capsaicin injection. NGFI-A, NGFI-B and Nurr1 ex pression persisted for 6 h. Since the IEGs studied had major differences in their temporospatial induction pattern, they are likely to be induced by d istinct stress-elicited factors and have separate target genes and roles in stress-induced glucocorticoid and catecholamine secretion. (C) 2000 Elsevi er Science BN. All rights reserved.