Alpha-1 adrenergic receptor binding and adrenergic-stimulated cyclic AMP production in rat cerebral cortex after chronic lithium treatment

Administration to rats of dietary lithium for 30 days was followed by evaluation of alpha-1 adrenergic receptor binding and of adrenergic-stimulated cyclic AMP (cAMP) accumulation in rat cerebral cortex. Chronic lithium treatment did not alter the binding characteristics of [³H]prazosin or the proportion of alpha-1 adrenergic receptor subtypes distinguished by chlorethylclonidine (CEC) pretreatment in rat cerebral cortical membranes. Accumulation of cAMP in cortical slices incubated with adrenergic agonists was unaffected in lithium-treated rats. These results demonstrate that chronic lithium treatment-induced reduction of norepinephrine (NE)-stimulated phosphoinositide (PI) hydrolysis (Casebolt and Jope, 1987) is not due to changes in the alpha-1 adrenergic receptor and is more sensitive to in vivo lithium treatment than is adrenergic-stimulated cAMP accumulation.