beta-Lipotropin: localization of cells and axons in rat brain by immunocytochemistry.

Abstract
Using specific antisera to human .beta.-lipotropin, cells and axons with .beta.-lipotropin like immunoreactivity were visualized in rat brain and pituitary. The .beta.-lipotropin so localized is well delineated and contained in the cytoplasm of cells and in beaded axons. Areas of greatest .beta.-lipotropin content are hypothalamus (with cell bodies in the medial basal hypothalamus and arcuate regions), periventricular nucleus of the thalamus, ansa lenticularis, zona compacta of the substantia nigra, medial amygdaloid nucleus, zona incerta, periaqueductal central gray area, locus ceruleus and a few fibers in the reticular formation. The question of the exact relationship of .beta.-lipotropin and methionine-enkephalin remains open because some brain area contain both substances and some areas contain only one or the other.