SOURCE OF CORTICOTROPIN-RELEASING HORMONE-LIKE INNERVATION OF THE ADRENAL-GLANDS OF FETAL AND POSTNATAL SHEEP

In pre- and postnatal sheep the irregularly shaped adrenal corticomedu llary interface is innervated by corticotropin-releasing hormone (CRH) -like beaded fibers. Since CRH-like staining is also seen in the splan chnic nerves, we examined the intermediolateral sympathetic columns (I SC) of the thoracic (T) spinal cords (segments 5-13) of 12 pre- and po stnatal sheep for CRH-like immunocytochemical reactivity and in a subs et of fetuses, fluorogold immunoreactivity after fluorogold injection to the left adrenal medulla. All animals had CRH-like immunopositive n eurons in the ISC from all thoracic segments. The number of CRH-like p ositive neurons per thoracic segment did not change either from anteri or to posterior within groups nor were there differences between group s. Fluorogold immunopositive neurons occurred in the ISC of all inject ed animals from T-5 to T-13. Upon double immunostaining, some ISC CRH- Like immunopositive neurons also demonstrated fluorogold immunopositiv ity. Taken together, these studies indicate that there are CRH-like im munopositive neurons in the ISC of pre- and postnatal sheep and that s ome of these CRH-like immunopositive neurons innervate the adrenal med ulla. (C) 1997 Elsevier Science B.V.