Application of avidin-biotinized peroxidase (ABC) method for immunocytochemical localization of corticotropin-releasing factor (CRF) in rat hypothalamus

Studies on immunocytochemical localization of corticotropin-releasing factor (CRF) were performed in the rat hypothalamus using avidin-biotinized peroxidase (ABC) and PAP techniques. In intact and control animals CRF-immunoreactive nerve fibers were observed within outer layer of median eminence. In the adrenalectomized animals, CRF was also demonstrated in perikarya of neurocytes and in their projections in paraventricular nucleus of the hypothalamus. In both immunocytochemical techniques identical localization of CRF was obtained. However, reaction intensity was greater with the ABC technique than with the PAP one. In bilateral adrenalectomized animals, a greater number of CRF-immunoreactive neural fibers were observed in the median eminence than in control rats and rats subjected to sham operation.