Immunoreactivities for antisera to three putative neuropeptides of the rat melanin-concentrating hormone precursor are coexpressed in neurons of the rat lateral dorsal hypothalamus.

Antisera (AS) raised against rat melanin-concentrating hormone (rMCH) and against two additional peptides sequences derived from the rat MCH precursor (neuropeptide glutamic acid-isoleucineamide (NEI), and neuropeptide glycine-glutamic acid (NGE)) exclusively stained the hypothalamic neurons previously described using AS to salmon MCH, human somatocrinin 1-37 (GRF37) and alpha-MSH. Liquid phase and dot-blot controls for specificity indicated that rMCH-, NEI- and NGE-AS bound epitopes recognized by sMCH-, alpha-MSH- and GRF-37-AS, respectively. The distinct intracellular patterns of immunoreactivity obtained in control animals with rMCH-, NGE- and NEI-AS, as well as the changes observed after intracerebroventricular injection of colchicine matched previous findings using sMCH-, GRF37- and alpha-MSH-AS.