title: Changes in neutrophil met-enkephalin containing peptides in episodic cluster headache.
abstract: We have previously demonstrated an increase in plasma met-enkephalin levels during the pain attacks in episodic cluster headache. The present study was undertaken in order to clarify the source of the plasma met-enkephalin increase. Recent evidence has shown that peripheral blood polymorphonuclear cells contain peptides derived from the proenkephalin A system, which can be released by specific stimuli. We studied neutrophil met-enkephalin containing peptides (NMECP) in 27 episodic cluster headache patients: 24 in a cluster period (6 of them during a pain attack), and 3 in the remission period. Neutrophil met-enkephalin containing peptide levels (after sequential enzymatic digestion with trypsin and carboxypeptidase B) were determined by radioimmunoassay with specific antiserum. Neutrophil peptide concentration (pmol/mg prot) was lower (p less than 0.01) in patients during the pain attack (14.4 +/- 0.36) than after their pain had subsided (36.7 +/- 0.31) and lower than in the remission period patients (35.8 +/- 0.4). We conclude that neutrophil met-enkephalin containing peptides decrease during pain in episodic cluster headache, and that they may be involved in the concomitant plasma met-enkephalin increase.
authors.affiliation: Centro de Investigaciones Endocrinológicas, CONICET, Hospital de Niños Dr. Ricardo Gutiérrez, Buenos Aires, Argentina.
authors.forename: M L
authors.initials: ML
authors.lastname: Figuerola
authors.forename: O
authors.initials: O
authors.lastname: Vindrola
authors.forename: M B
authors.initials: MB
authors.lastname: Barontini
authors.forename: J A
authors.initials: JA
authors.lastname: Leston
mesh_terms: D000328:Adult; D003027:Cluster Headache / Q000097:blood*; D004744:Enkephalin, Methionine / Q000097:blood*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009504:Neutrophils / Q000737:chemistry*; D010455:Peptides / Q000097:blood*
chemical_list: D010455:Peptides; D004744:Enkephalin, Methionine