title: Uptake of the antisecretory factor peptide AF-16 in rat blood and cerebrospinal fluid and effects on elevated intracranial pressure.
abstract: BACKGROUND
  AF-16 is a 16-amino-acid-long peptide derived from the amino-terminal part of the endogenous protein, antisecretory factor (AF). AF-16 in vivo has been shown to regulate dysfunctions in the water and ion transport system under various pathological conditions and also to counteract experimentally increased tissue pressure.
  
  
  METHODS
  Rats were subjected to a cryogenic brain injury in order to increase the intracranial pressure (ICP). The distribution of AF-16 in blood and CSF after intravenous or intranasal administration was determined in injured and control rats. ICP was monitored in freely moving, awake rats, by means of an epidural pressure transducer catheter connected to a wireless device placed subcutaneously on the skull. The continuous ICP registrations were achieved by means of telemetry.
  
  
  RESULTS
  Intranasal administration of AF-16 resulted in a significantly higher CSF concentrations of AF-16 in injured than in control rats, 1.3 versus 0.6 ng/ml, whereas no difference between injured and control rats was seen when AF-16 was given intravenously. Rats subjected to cryogenic brain injury developed gradually increasing ICP levels. Intranasal administration of AF-16 suppressed the increased ICP to normal values within 30 min.
  
  
  CONCLUSIONS
  Optimal AF-16 concentrations in CSF are achieved after intranasal administration in rats subjected to a cryogenic brain injury. The ability of AF-16 to suppress an increased ICP was manifested.
authors.affiliation: Institute of Biomedicine, Sahlgrenska Academy, University of Gothenburg, P.O.B. 440, 405 30, Göteborg, Sweden.
authors.forename: Mohamed
authors.initials: M
authors.lastname: Al-Olama
authors.forename: Stefan
authors.initials: S
authors.lastname: Lange
authors.forename: Ivar
authors.initials: I
authors.lastname: Lönnroth
authors.forename: Kliment
authors.initials: K
authors.lastname: Gatzinsky
authors.forename: Eva
authors.initials: E
authors.lastname: Jennische
mesh_terms: D000818:Animals; D019586:Intracranial Hypertension / Q000097:blood / Q000134:cerebrospinal fluid / Q000188:drug therapy*; D007427:Intracranial Pressure; D008297:Male; D010455:Peptides / Q000097:blood / Q000134:cerebrospinal fluid / Q000493:pharmacokinetics* / Q000627:therapeutic use*; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D010455:Peptides; C533586:peptide AF-16