Neuromedin B-like peptides in rat brain: biochemical characterization, mechanism of release and localization in synaptosomes.
Neuromedin B-like peptides were characterized in the rat brain. A rabbit antisera was utilized which recognized neuromedin B but not bombesin or GRP. Using gel filtration and HPLC techniques, a major and minor peak of immunoreactivity was present in rat brain extracts. In both cases the main peak of immunoreactivity coeluted with synthetic neuromedin B. The density of neuromedin B-like peptides ranged 50-fold being greatest in the olfactory bulb and hypothalamus, intermediate in the hippocampus, spinal cord, medulla/pons, pituitary, midbrain, thalamus, striatum and cortex and lowest in the cerebellum. Release studies indicated that neuromedin B-like peptides were secreted from hypothalamic, olfactory bulb and thalamic slices in a Ca++-dependent manner when KCl (75 mM) was present. Also, the neuromedin B-like peptides in the rat brain were localized to synaptosomes. These data indicate that neuromedin B-like peptides may function as regulatory peptides in the CNS distinct from bombesin/GRP.
D000595:Amino Acid Sequence; D000818:Animals; D001839:Bombesin; D001921:Brain / Q000378:metabolism; D001923:Brain Chemistry; D007106:Immune Sera; D066298:In Vitro Techniques; D008297:Male; D015287:Neurokinin B / Q000031:analogs & derivatives*; D009479:Neuropeptides / Q000032:analysis* / Q000378:metabolism; D011863:Radioimmunoassay; D051381:Rats; D011919:Rats, Inbred Strains; D013574:Synaptosomes / Q000032:analysis*; D014018:Tissue Distribution
D007106:Immune Sera; D009479:Neuropeptides; D015287:Neurokinin B; C038393:neuromedin B; D001839:Bombesin