Arginine administration inhibits hippocampal Na +,K +-ATPase activity and impairs retention of an inhibitory avoidance task in rats

Abstract

In the present study we investigated the effect of acute administration of l-arginine (Arg) on hippocampal Na +,K +-ATPase activity and on retrieval of step-down inhibitory avoidance in adult rats. The action of l-NAME on the effects produced by Arg was also tested. Sixty-day-old rats were treated with a single intraperitoneal injection of saline (group I, control), arginine (0.8 g/kg) (group II), l-NAME (2 mg/kg) (group III) or arginine (0.8 g/kg) plus l-NAME (2 mg/kg) (group IV). Na +,K +-ATPase activity was significantly reduced in arginine-treated rats; this effect was prevented by l-NAME. Retrieval of the avoidance task was also significantly impaired by arginine, whereas the simultaneous injection of l-NAME prevented this effect. Present data strongly indicate that in vivo Arg administration reduces both Na +,K +-ATPase activity and memory modulation in rats probably through NO formation.