title: Endogenous morphine and codeine in the brain of non human primate.
abstract: BACKGROUND
  Morphine is the most used compound among narcotic analgesics. Apart from its presence in the poppy plant, morphine has been shown to be endogenously present in different tissues of mammals and lower animals.
  
  
  METHODS
  The presence of endogenous morphine and codeine was investigated by Gas Chromatography/ Mass Spectrometry (GC/MS) in the brain of non human primate. The release of endogenous morphine from monkey brain slices was studied in vitro in the presence of high potassium concentrations with and without calcium in the medium.
  
  
  RESULTS
  Endogenous morphine, and its direct precursor codeine, was for the first time detected by GC/MS in the brain of non human primate. High potassium concentrations depolarized neurons releasing endogenous morphine twofold above basal line levels in a calcium dependent mechanism.
  
  
  CONCLUSIONS
  This finding confirms the presence of the endogenous alkaloid throughout the phylogenesis of the nerve system of mammals and lower animals and indicates that endogenous morphine might function as a neuromodulator/neurotransmitter agent in the central nervous system (CNS) of non human primates.
authors.affiliation: Department of Medicine and Public Health, Institute of Forensic Medicine, University of Verona, Italy.
authors.forename: Carla
authors.initials: C
authors.lastname: Neri
authors.forename: Massimo
authors.initials: M
authors.lastname: Guarna
authors.forename: Enrica
authors.initials: E
authors.lastname: Bianchi
authors.forename: Dario
authors.initials: D
authors.lastname: Sonetti
authors.forename: Giacomo
authors.initials: G
authors.lastname: Matteucci
authors.forename: George B
authors.initials: GB
authors.lastname: Stefano
mesh_terms: D000818:Animals; D001921:Brain / Q000187:drug effects / Q000378:metabolism; D001923:Brain Chemistry / Q000187:drug effects; D002521:Cercopithecus / Q000378:metabolism*; D003061:Codeine / Q000032:analysis* / Q000378:metabolism / Q000494:pharmacology; D008401:Gas Chromatography-Mass Spectrometry; D008297:Male; D009020:Morphine / Q000032:analysis* / Q000378:metabolism / Q000494:pharmacology
chemical_list: D009020:Morphine; D003061:Codeine