The effect of (-)-4-(2-hydroxy-3(N-isopropylamino)-propoxyimino)-cis-carane on basal and forskolin-stimulated accumulation of cyclic AMP in the cerebral cortical slices of the rat

Carane derivative stereoisomers of different local anaesthetic and antiplatelet activity similarly potentiate forskolin-stimulated cyclic AMP response and bind to beta-adrenoceptors in the rat brain cortex

A carane derivative, KP-23 [RS](-)-4-(2-hydroxy-3)N-isopropylamino)-propoxyimino)-cis-carane, was earlier described as a potential local anaesthetic and antiplatelet agent, and the following studies revealed that its R and S stereoisomers, KP-23R and KP-23S, have different potencies in the infiltration anaesthesia and platelet aggregation tests. The effects of these stereoisomers on the cyclic AMP (cAMP) generating system and the displacement of [(3)H]CGP 12177 (a beta-adrenoceptor ligand) from its binding sites in the rat cerebral cortical tissue were investigated. The stereoisomers did not affect the basal cAMP level, but, at concentrations between 10(-4) and 10(-3) M, they elevated the forskolin-induced accumulation of cAMP with similar potency. The compounds displaced [(3)H]CGP 12177, however the stereoisomer R was less potent than the racemic KP-23 and the S form (K(i) = 64.1 +/- 5.9 nM, 161.1 +/- 10 nM and 62.1 +/- 5.6 nM for KP-23, KP-23R and KP-23S, respectively). The fact that the stereoisomers differed in both tests only slightly, if at all, suggests that their pharmacological effects are not related to the action on the beta-adrenoceptor/adenylate cyclase system.