Fenproporex is an amphetamine-based anorectic which is rapidly converted into amphetamine in vivo. Na+
-ATPase is a membrane-bound enzyme necessary to maintain neuronal excitability. Considering that the effects of fenproporex on brain metabolism are poorly known and that Na+
-ATPase is essential for normal brain function, this study sought to evaluate the effect of this drug on Na+
-ATPase activity in the hippocampus, hypothalamus, prefrontal cortex, and striatum of young rats.
Young male Wistar rats received a single injection of fenproporex (6.25, 12.5, or 25 mg/kg intraperitoneally) or polysorbate 80 (control group). Two hours after the last injection, the rats were killed by decapitation and the brain was removed for evaluation of Na+
Fenproporex decreased Na+
-ATPase activity in the striatum of young rats at doses of 6.25, 12.5, and 25 mg/kg and increased enzyme activity in the hypothalamus at the same doses. Na+
-ATPase activity was not affected in the hippocampus or prefrontal cortex.
Fenproporex administration decreased Na+
-ATPase activity in the striatum even in low doses. However, in the hypothalamus, Na+
-ATPase activity was increased. Changes in this enzyme might be the result of the effects of fenproporex on neuronal excitability.
Keywords: Na+, K+-ATPase activity; brain; fenproporex