PARADOXICAL ACTION OF THE CANNABINOID WIN-55,212-2 IN STIMULATED AND BASAL CYCLIC-AMP ACCUMULATION IN RAT GLOBUS-PALLIDUS SLICES

The effects of the synthetic cannabinoid WIN 55,212-2 on forskolin-sti mulated and basal adenosine 3':5'-cyclic monophosphate (cyclic AMP) ac cumulation in globus pallidus slices were investigated. WIN 55,212-2 c aused a concentration-dependent decrease in forskolin-stimulated cycli c AMP accumulation in globus pallidus slices (maximum inhibition 36% f or 30 mu M). This effect was blocked by the cannabinoid receptor antag onist SR 141716A (100 mu M). WIN 55,212-2 alone caused a concentration -dependent increase in cyclic AMP levels in unstimulated slices (maxim um increase 52.6% for 100 mu M). This effect was also blocked by SR 14 1716A (100 mu M). In either forskolin-stimulated or unstimulated condi tions SR 1417161A (100 mu M) did not affect cyclic AMP levels.