The use of cyclic AMP efflux studies in attempts to determine the effects of morphine on cyclic AMP formation in striatal slices.

The effect of morphine and naloxone on basal and forskolin-stimulated efflux of cyclic AMP from rat striatal slices was examined. Neither morphine nor naloxone had any consistent effect on the basal efflux of cyclic AMP. Forskolin produced a time and dose-dependent enhancement of cyclic AMP efflux. Neither morphine nor naloxone affected this forskolin-enhanced release. These results suggest that measurements of cyclic AMP released from brain slices do not accurately reflect effects on adenylate cyclase inhibition by opiates.