MODULATION BY MIANSERIN PRETREATMENT OF THE CHRONIC ELECTROCONVULSIVESHOCK EFFECTS ON THE ADRENERGIC SYSTEM IN THE CEREBRAL-CORTEX OF THE RAT

The effect of a series of electroconvulsive shock (ECS) applied after chronic administration of mianserin was tested in the rat. ECS in the group pretreated with mianserin produced a significantly larger increa se in the density of alpha(1)-adrenoceptors, while its effect on beta- adrenoceptor density and cyclic AMP response to noradrenaline were ind ependent of the mianserin pretreatment. However, the cyclic AMP respon se to isoproterenol in the presence of 12-O-tetradecanoylphorbol 13-ac etate (TPA) in slices from rats receiving ECS after mianserin pretreat ment was significantly higher than in the slices of rats receiving eit her treatment alone. While ECS did not change the responsiveness of al pha(1)-adrenoceptors as measured by IP response to noradrenaline, it s ignificantly attenuated the responses when given after mianserin; mian serin alone significantly increased the responsiveness of alpha(1)-adr enoceptors. All treatments reduced the attenuation of IP response by p rotein kinase C activator TPA. The results suggest that pretreatment w ith mianserin may affect the ECS action of direct and PKC-modulated ad renergic response systems.