TABLE 1

The role of adenosine A2A receptors and adenylyl cyclases in withdrawal-induced cAMP superactivation

NAc/striatal neurons were transiently transfected with or without siRNAs for AC2, AC4, AC5, AC7, AC5 + AC7, or scramble control, respectively. Twenty-four hours after transfection, cells were treated with 100 nM morphine for 18 h followed by 5-h withdrawal (W.D.) in the presence or absence of adenosine deaminase (ADA, 1 unit/ml) or the A2A antagonist KW-6002 (100 nM). Data are the mean ± S.E.M. of at least three experiments with each treatment carried out in triplicates.


Treatment

cAMP Increase
%
W.D. 78 ± 9
W.D. + ADA 2 ± 5*
W.D. + KW-6002 1 ± 3*
W.D. + Control SiRNA 71 ± 5
W.D. + AC2 SiRNA 69 ± 12
W.D. + AC4 SiRNA 72 ± 10
W.D. + AC5 SiRNA 24 ± 4*
W.D. + AC7 SiRNA 49 ± 7*
W.D. + (AC5 + AC7) SiRNA
11 ± 4*
  • * P < 0.05 compared with withdrawal control (one-way ANOVA and Dunnett's test).