title: Locomotor stimulation by acute propofol administration in rats: Role of the nitrergic system.
abstract: BACKGROUND
  The addictive potential of propofol has been scientifically discussed. Drugs' psychostimulant properties that can be assessed via measurements of locomotor activity are linked to their addictive properties. No studies that have investigated the effects of propofol on locomotor activity have been reported to date. The present study sought to investigate the effects and possible mechanisms of action of propofol on locomotor activity in rats.
  
  
  METHODS
  Adult male albino Wistar rats (250-330g) were used as subjects. The locomotor activities of the rats were recorded for 30min immediately following intraperitoneal administration of propofol (20 and 40mg/kg), saline or vehicle (n=8 for each group). NG-nitro arginine methyl ester (l-NAME, 15-60mg/kg), a nitric oxide (NO) synthase inhibitor, and haloperidol (0.125-5mg/kg), a non-specific dopamine receptor antagonist, were also administered to other groups of rats 30min prior to the propofol (40mg/kg) injections, and locomotor activity was recorded for 30min immediately after propofol administration (n=8 for each group).
  
  
  RESULTS
  Propofol produced significant increases in the locomotor activities of the rats in the first 5min of the observation period [F(2,21)=9.052; p<0.001]. l-NAME [F(4,35)=3.112; p=0.02] but not haloperidol [F(4,35)=2.440; p=0.067] pretreatment blocked the propofol-induced locomotor hyperactivity. l-NAME did not cause any significant change in locomotor activity in naïve rats [F(2,21)=0.569; p=0.57].
  
  
  CONCLUSIONS
  Our results suggest that propofol might cause a short-term induction of locomotor activity in rats and that this effect might be related to nitrergic but not dopaminergic mechanisms.
authors.affiliation: Department of Anaesthesiology and Reanimation, Ankara Numune Training and Research Hospital, Ankara, Turkey.
authors.forename: Aysu H
authors.initials: AH
authors.lastname: Tezcan
authors.affiliation: Neuropsychopharmacology Application and Research Center (NPARC), Üsküdar University, Istanbul, Turkey.
authors.forename: Ayşe
authors.initials: A
authors.lastname: Özçetin
authors.affiliation: Department of Anaesthesiology and Reanimation, Faculty of Medicine, Düzce University, Düzce, Turkey.
authors.forename: Onur
authors.initials: O
authors.lastname: Özlü
authors.affiliation: Neuropsychopharmacology Application and Research Center (NPARC), Üsküdar University, Istanbul, Turkey.
authors.forename: Burcu
authors.initials: B
authors.lastname: Çevreli
authors.affiliation: Neuropsychopharmacology Application and Research Center (NPARC), Üsküdar University, Istanbul, Turkey. Electronic address: tuzbay@uskudar.edu.tr.
authors.forename: Tayfun
authors.initials: T
authors.lastname: Uzbay
mesh_terms: D018686:Anesthetics, Intravenous / Q000494:pharmacology*; D000818:Animals; D018492:Dopamine Antagonists / Q000494:pharmacology; D006220:Haloperidol / Q000494:pharmacology; D008297:Male; D009043:Motor Activity / Q000187:drug effects*; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology; D009566:Nitrates / Q000378:metabolism*; D009569:Nitric Oxide / Q000502:physiology; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors; D015742:Propofol / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D013268:Stimulation, Chemical
chemical_list: D018686:Anesthetics, Intravenous; D018492:Dopamine Antagonists; D009566:Nitrates; D009569:Nitric Oxide; D019001:Nitric Oxide Synthase; D006220:Haloperidol; D019331:NG-Nitroarginine Methyl Ester; D015742:Propofol
keywords: Abuse and dependence; Locomotor activity; Nitric oxide; Propofol; Rat(s)