Ultrastructural immunohistochemical localization of adrenocorticotropin and beta-lipotropin in the rat brain.

In an attempt to identify the cells and organellel containing ACTH and beta-lipotropin in the rat brain, an immunocytochemical localization of these two peptides was performed at the electron microscopic level. Both ACTH and beta-lipotropin were localized in dense core vesicles of about 60-80 nm in diameter. Using serial sections, it has been possible to demonstrate that these peptides are contained not only in the same neuronal cell bodies, but also in the same dense core vesicles.