[The different mechanism of the inhibition by buspirone and its camphorimide analogs of 5-HT3-serotoninergic effects].

Serotonin evokes the depolarization and the membrane resistance lowering of rat dorsal root ganglion neurones when a K(+)--conductance of the neuronal membranes is blocked by Cs+ intracellular injection. These 5-HT3-effects ere diminished and removed by preliminary superfusion of the ganglions with saline containing busperone or its structural analogues. The effects of camphorimide analogues of buspirone (campirone, pyricapirone) could not be reproduced in case of the protein kinase A blockade by tolbutamide (100 microM/l). It is suggested that camphorimide analogues are the 5-HT3 receptor blockers while busperone and ipsapirone modulate 5-HT3 receptor affinity by decreasing the protein kinase A activity.