delta 9-Tetrahydrocannabinol-induced changes in beta-adrenergic receptor binding in mouse cerebral cortex

The effects of 3 cannabinoids, delta 9-tetrahydrocannabinol (delta 9-THC), 11-OH-delta 9-tetrahydrocannabinol (11-OH-delta 9-THC) and cannabidiol (CBD) on the binding of [3H]dihydroalprenolol [( 3H]DHA) to mouse brain beta-adrenergic receptors were determined. In vitro, delta 9-THC and 11-OH-delta 9-THC increased the specific binding of [3H]DHA. The increased specific binding of [3H]DHA was due to an increase in receptor affinity as indicated by a decrease in the dissociation constant (Kd). CBD had no effect on binding. Chronic administration of delta 9-THC in vivo caused a decrease in the number of [3H]DHA binding sites with no change in Kd.