Subcellular localization of immunoreactive alpha-melanocyte stimulating hormone in human brain.
The regional and subcellular distribution of immunoreactive alpha-melanocyte stimulating hormone (alpha-MSHi) in the post mortem adult human brain was investigated. alpha-MSHi was highly concentrated in medial basal hypothalamic tissue (1.02 ng/mg protein). Lower levels of alpha-MSHi were present in the optic chiasm and mammillary bodies, 0.08 and 0.11 ng/mg protein, respectively. The concentrations of alpha-MSHi in cerebellum and frontal cerebral cortex were 1/1,000th that of the medial basal hypothalamus. When medial basal hypothalamic homogenates were subjected to discontinuous or continuous sucrose density gradients, alpha-MSHi was found to be associated primarily with subcellular particles which resembled isolated nerve terminals, i.e., synaptosomes. Low to undetectable amounts of alpha-MSHi were found in the cytosol or the myelin/microsome fraction of the gradients. The results of these studies are consistent with the view that alpha-MSH is a neuronal peptide in the human brain.
D001921:Brain / Q000378:metabolism*; D001931:Brain Mapping; D002531:Cerebellum / Q000378:metabolism; D005625:Frontal Lobe / Q000378:metabolism; D006801:Humans; D007033:Hypothalamus, Middle / Q000378:metabolism; D008326:Mammillary Bodies / Q000378:metabolism; D009074:Melanocyte-Stimulating Hormones / Q000378:metabolism*; D009474:Neurons / Q000378:metabolism; D009897:Optic Chiasm / Q000378:metabolism; D013347:Subcellular Fractions / Q000378:metabolism; D013574:Synaptosomes / Q000378:metabolism*
D009074:Melanocyte-Stimulating Hormones