beta-Lipotropin in brain: localization in hypothalamic neurons by immunoperoxidase technique.

beta-Lipotropin (beta-LPH) has been localized in hypothalamus and pituitary of sheep and ox by the immunoperoxidase technique. In both species beta-LPH was found in perikarya of arcuate neurons as well as in cells of the anterior and intermediate lobes of the pituitary. A large number of immunoreactive axons were found in the arcuate region; some appeared to innervate other neurons and others projected to portal capillaries. Stained fiber segments were also scattered throughout the hypothalamus. The presence of beta-LPH in hypothalamic neurons supports the possibility that brain beta-LPH may be a precursor for opiate-like or other peptides which may be involved in neuromodulation or neurohormonal activities.