Sensitization to the motor stimulant effects of 3,4-methylenedioxypyrovalerone (MDPV) and cross-sensitization to methamphetamine in rats.
BACKGROUND
In recent years, there has been a dramatic increase in abuse of the synthetic cathinone 3,4-methylenedioxypyrovalerone (MDPV), often in combination with other illicit stimulants.


OBJECTIVE
We sought to determine if repeated exposure to MDPV would produce sensitization to the motor stimulant effects of the drug, and whether cross-sensitization would develop with the stimulant effects of methamphetamine (METH).


METHODS
Male Sprague-Dawley rats were administered MDPV (1 or 5 mg/kg) or saline once daily for 5 days at 24 hour intervals, or were administered MDPV (1 mg/kg) or saline once daily for 5 days at 48 hour intervals. For cross-sensitization experiments, rats were administered METH (1 mg/kg) or MDPV (1 or 5 mg/kg) once daily for 5 days at 48 hour intervals, and following a 5 day incubation period, were given an acute challenge injection of either MDPV (0.5 mg/kg) or METH (0.5 mg/kg), respectively.


RESULTS
Rats repeatedly administered MDPV (1 mg/kg) every 48 hours, but not every 24 hours, demonstrated increased motor activity when given either a subsequent challenge of MDPV (0.5 mg/kg i.p.) or METH (0.5 mg/kg), indicating the development of behavioral sensitization and cross-sensitization, respectively. Moreover, rats repeatedly administered METH (1 mg/kg) every 48 hours did not exhibit cross-sensitization to the motor stimulating effects of a subsequent challenge with MDPV (0.5 mg/kg).


CONCLUSIONS
These results suggest that specific patterns of MDPV administration may lead to lasting changes in behavioral responses to subsequent METH exposure.
Arizona State University, Department of Psychology, Tempe, AZ, USA.
Lucas R
LR
Watterson
Arizona State University, Department of Psychology, Tempe, AZ, USA.
Peter R
PR
Kufahl
Arizona State University, Department of Psychology, Tempe, AZ, USA.|Hendrix College, Department of Psychology, Conway, AR, USA.
Sara B
SB
Taylor
Arizona State University, Department of Psychology, Tempe, AZ, USA.
Natali E
NE
Nemirovsky
Arizona State University, Department of Psychology, Tempe, AZ, USA.|Arizona State University, Interdisciplinary Graduate Program in Neuroscience, Tempe, AZ, USA.
M Foster
MF
Olive
MDPV; cross-sensitization; methamphetamine; psychostimulant; sensitization; synthetic cathinone