title: Comparison of the behavioral and cardiovascular effects of mephedrone with other drugs of abuse in rats.
abstract: BACKGROUND
  Exceedingly little experimental research exists on the popular recreational drug mephedrone (4-methylmethcathinone) despite clinical reports concerning its behavioral and cardiovascular toxicity.
  
  
  OBJECTIVE
  To characterize mephedrone preclinically by examining its capacity to (1) serve as a discriminative stimulus, (2) disrupt the acquisition of response sequences, and (3) disrupt mean arterial pressure (MAP) and heart rate (HR).
  
  
  RESULTS
  In one group of subjects that reliably discriminated 3.2 mg/kg of mephedrone from saline (n = 9), substitution tests indicated that stimulants (cocaine, MDMA, and methamphetamine) more closely approximated the mephedrone discriminative stimulus than non-stimulants (fenfluramine, morphine, and phencyclidine), although none fully substituted. In a second group (n = 6), mephedrone (0.56-10 mg/kg, i.p.) dose-dependently decreased response rate and increased errors in both components of a procedure in which subjects either acquired a new response sequence each session (repeated acquisition) or completed the same response sequence each session (performance). Finally, in a third group (n = 12), radio telemetry probes were used to measure the changes in MAP and HR elicited by mephedrone and then compared them to a known stimulant, methamphetamine. In these studies, mephedrone (0.01-9 mg/kg, i.v.) elicited increases in MAP and HR that were very similar to those elicited by methamphetamine (0.01-9 mg/kg, i.v.). The tachycardia and pressor responses to mephedrone (3 mg/kg) were blocked by the β-blocker atenolol (1 mg/kg, i.v.) and the α1, α2-blocker phentolamine (3 mg/kg, i.v.), respectively.
  
  
  CONCLUSIONS
  Mephedrone produces behavioral and cardiovascular responses that are similar to other stimulants; however, differences from the classical stimulants were also apparent.
authors.affiliation: Department of Pharmacology, Louisiana State University Health Sciences Center, 1901 Perdido Street, New Orleans, LA 70112, USA.
authors.forename: Kurt J
authors.initials: KJ
authors.lastname: Varner
authors.forename: Kyle
authors.initials: K
authors.lastname: Daigle
authors.forename: Peter F
authors.initials: PF
authors.lastname: Weed
authors.forename: Peter B
authors.initials: PB
authors.lastname: Lewis
authors.forename: Sarah E
authors.initials: SE
authors.lastname: Mahne
authors.forename: Ananthakrishnan
authors.initials: A
authors.lastname: Sankaranarayanan
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Winsauer
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects*; D001794:Blood Pressure / Q000187:drug effects*; D003216:Conditioning, Operant / Q000187:drug effects; D004193:Discrimination Learning / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D006339:Heart Rate / Q000187:drug effects*; D013287:Illicit Drugs / Q000633:toxicity*; D008297:Male; D008694:Methamphetamine / Q000031:analogs & derivatives* / Q000633:toxicity; D051381:Rats; D020318:Rats, Long-Evans; D017207:Rats, Sprague-Dawley
chemical_list: D013287:Illicit Drugs; D008694:Methamphetamine; C548233:mephedrone