The Role of L-Carnitine in the Activities of Membrane-Bound Enzymes in the Brains of Aged Rats

Abstract

Membrane-bound enzymes play a crucial role in neuronal function. These enzymes are thought to be responsible for maintenance of membrane potential and impulse propagation. An altered membrane potential might be responsible for age-related neuronal changes. We evaluated the effect of L-carnitine (300 mg/kg body weight/day) on the activities of membrane bound enzymes (Na⁺,K⁺-ATPase, Ca²⁺-ATPase, and Mg²⁺-ATPase) and lipid peroxidation in discrete areas of young and aged rat brains. A progressive increase in lipid peroxidation in all five regions of the brain has been observed. The activities of membrane-bound enzymes were found to be decreased significantly in cortex, hippocampus, and striatum. The results show that there is a negative correlation between lipid peroxidation and activities of membrane-bound enzyme. L-Carnitine lowers the status of lipid peroxidation and increases the activity of membrane-bound enzymes. Our results suggest that L-carnitine has a tendency to inhibit lipid peroxidation and thereby helps the brain to maintain the activities of membranebound enzymes.