PROTEIN-KINASE-C ACTIVATION AND ANTIAMNESIC EFFECT OF ACETYL-L-CARNITINE - IN-VITRO AND IN-VIVO STUDIES

Drugs belonging to different chemical classes having the ability to im prove behavioral performance in animal learning and memory tests may s hare the common ability to stimulate protein kinase C activity in rat brain cortex. In vitro acetyl-L-carnitine (100 nM) promoted in rat bra in cortex slices a significant increase in particulate activity associ ated with lower soluble protein kinase C activity and produced a direc t stimulation of the enzyme in both the cortex and hippocampus. In viv o a significant increase in particulate protein kinase C activity was observed in the group of rats treated with 60 mg/kg acetyl-L-carnitine , a dose shown to be effective in improving the cognitive deficits ind uced by scopolamine in the Morris maze test. The results suggest that acetyl-L-carnitine increases particulate protein kinase C activity in the cortex both in vitro and in vivo. This effect in the in vivo exper iments seems to be observed only with doses that are effective in impr oving the performance of rats in a spatial learning task.