title: Analgesic dipeptide, kyotorphin (Tyr-Arg), is highly concentrated in the synaptosomal fraction of the rat brain.
abstract: To examine the physiological role of the analgesic dipeptide, kyotorphin (Tyr-Arg), which was isolated from the mammalian brain, its subcellular localization was studied. Kyotorphin was determined using high-performance liquid chromatography (HPLC) with an electrochemical detector. This dipeptide was found to be concentrated in the crude mitochondrial (P2) fraction. Further subfractionation of the P2 fraction revealed that kyotorphin was exclusively localized in the synaptosomal fraction.This finding suggests the possibility that kyotorphin has a neurotransmitter/neuromodulator role in the brain.
mesh_terms: D000818:Animals; D001921:Brain / Q000378:metabolism*; D004151:Dipeptides / Q000378:metabolism*; D004723:Endorphins / Q000378:metabolism*; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D009435:Synaptic Transmission; D013574:Synaptosomes / Q000378:metabolism*
chemical_list: D004151:Dipeptides; D004723:Endorphins; C019448:kyotorphin