title: Cysteine: depolarization-induced release from rat brain in vitro.
abstract: Compounds released on depolarization in a Ca2+-dependent manner from rat brain slices were screened to identify candidates for neuroactive substances. Lyophilized superfusates were analyzed by reversed-phase HPLC after derivatization with 9-fluorenyl N-succinimidyl carbonate. One of the compounds that showed an increase of concentration in superfusates in the presence of iodoacetamide was identified as the cysteine (Cys) derivative, S-carboxamidomethylcysteine, by fast atom bombardment mass spectrometry and other methods. This stable Cys derivative originates from endogenous, extracellular Cys. The finding led to a method for quantification of Cys in superfusates by immediate cooling of the superfusates to 0 degrees C and reaction of Cys with N-ethylmaleimide. Depolarization-induced Ca2+-dependent release of Cys was most prominent in the neocortex, followed by the mesodiencephalon, striatum, and cerebellum. This suggests that Cys is released from a neuronal compartment and might be involved in neurotransmission.
authors.affiliation: Brain Research Institute, University of Zürich, Switzerland.
authors.forename: H J
authors.initials: HJ
authors.lastname: Keller
authors.forename: K Q
authors.initials: KQ
authors.lastname: Do
authors.forename: M
authors.initials: M
authors.lastname: Zollinger
authors.forename: K H
authors.initials: KH
authors.lastname: Winterhalter
authors.forename: M
authors.initials: M
authors.lastname: Cuénod
mesh_terms: D000818:Animals; D001921:Brain / Q000378:metabolism* / Q000502:physiology; D002851:Chromatography, High Pressure Liquid; D003545:Cysteine / Q000032:analysis / Q000378:metabolism*; D004594:Electrophysiology; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains
chemical_list: D003545:Cysteine