Membrane changes in rat erythrocyte ghosts on ghee feeding

Alterations in membrane lipid composition is known to result in functional and structural changes in the membrane, and dietary lipids play an importan t role in this change. It was of interest to study the influence of ghee fe eding to the rat on membrane structure and function. The activities of memb rane bound enzymes Na+ K+ ATPase and Acetylcholinesterase were studied as a n index of membrane changes. Male weanling rats were fed 2.5% fresh or ther mally oxidized ghee in the diet for a period of 8 weeks. The control rats w ere fed groundnut oil. A decrease of 28% in the membrane fluidity of erythr ocyte ghost membranes was observed in the oxidized ghee fed group at 37 deg rees C, by fluorescence polarization measurements using 1,6-Diphenyl-1,3,5- hexatriene as a probe. The activities of Na+ K+ ATPase and Acetylcholineste rase showed an increase of 65% and 200% respectively after feeding oxidized ghee (2.5%). Also changes in Na+, K+ and ATP kinetics were observed in the se rats. Increased membrane lipid peroxidation (80%) and C/PL ratio (11%) i n the oxidized ghee fed group was observed. Marginal changes in the fatty a cid composition were also seen. Further, an increase in the osmotic fragili ty of erythrocytes was observed in the oxidized ghee fed rats. It is inferr ed from these experiments that consumption of oxidized ghee with the diet a ffects the erythrocyte ghost membrane structure and function at 2.5% level, whereas consumption of fresh ghee has no effect on the erythrocyte membran e.