Peripheral noradrenergic function during chronic lithium treatment in the rat.

Noradrenergic function was evaluated in the rat vas deferens following chronic treatment with lithium (30 mM in the diet for 2 weeks followed by 50 mM for 1 week). No alteration could be detected in: a) 3H-noradrenaline release evoked by electrical field stimulation, b) alpha 1-adrenoceptor function as assessed by contractile response to noradrenaline, c) active neuronal uptake of 3H-noradrenaline, d) alpha 2-adrenoceptor activity, as assessed by yohimbine-enhancement of evoked release of 3H-noradrenaline. The data argue against a primary action of lithium on the noradrenergic nerve. On the other hand, these findings do not rule out the possibility that the function of CNS noradrenergic neurons could be altered as a result of the known effects of lithium on the phosphatidyl-inositol system, and the greater sensitivity of CNS neurons to depletion of the neuronal membrane inositol pool.