MELANIN-CONCENTRATING HORMONE IN THE HUMAN BRAIN

The presence of human melanin-concentrating hormone (MCH) was studied in the human brain by radioimmunoassay and immunocytochemistry. Immuno reactive MCH concentrations in the human brain ranged from 0.07 to 19. 7 pmol/g wet weight. High performance liquid chromatography of the hyp othalamus showed a large immunoreactive peak in the position of human/ rat MCH, which was eluted 9 min later than that of salmon MCH. Free-fl oating sections (40 mum) of the hypothalamus were immunostained. Posit ive MCH immunostaining was found in perifornical, tuberomammillary, an d posterior nuclei. Numerous MCH-immunoreactive nerve fibers were obse rved throughout the hypothalamus. The presence of high concentrations of MCH in the human brain, in particular in the hypothalamus, suggests that MCH is a neurotransmitter, a neuromodulator, or a neurohormone i n man.