Modulation by Mianserin Pretreatment of the Chronic Electroconvulsive Shock 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 increase in the density of α1‐adrenoceptors, while its effect on β‐adrenoceptor density and cyclic AMP response to noradrenaline were independent of the mianserin pretreatment. However, the cyclic AMP response to isoproterenol in the presence of 12‐O‐tetradecanoylphorbol 13‐acetate (TPA) in slices from rats receiving ECS after mianserin pretreatment was significantly higher than in the slices of rats receiving either treatment alone. While ECS did not change the responsiveness of α1‐adrenoceptors as measured by IP response to noradrenaline, it significantly attenuated the responses when given after mianserin; mianserin alone significantly increased the responsiveness of α1‐adrenoceptors. All treatments reduced the attenuation of IP response by protein kinase C activator TPA. The results suggest that pretreatment with mianserin may affect the ECS action of direct and PKC‐modulated adrenergic response systems.