Influence of dietary lipids on the effect of chlorpromazine on membrane properties of rabbit red cells.

The effect of diets containing different types of common natural oils on physical properties of red cells was investigated by using rabbits. The rabbits were fed for 18 months on a standard diet in which 8% of its energy content was provided by safflower oil and 32% energy by either more safflower oil or fish oil, linseed oil, olive oil or palm oil. Erythrocyte deformability was significantly decreased by the fish oil diet compared with each of the other diets. Osmotic fragility was significantly less (66 mM) for red cells from rabbits fed on the linseed oil diet, and significantly greater (71 mM) for red cells from rabbits on the fish oil diet, than for red cells from rabbits on the other three diets which did not differ significantly from each other (68 mM). With rabbits on the standard diet, the resistance of their erythrocytes to osmotic haemolysis was increased by chlorpromazine at concentrations below and decreased by concentrations above 30 microM. The dietary oils caused significant changes in the effects of chlorpromazine on osmotic fragility. The concentration at which the effect of chlorpromazine reversed from antihaemolytic to prohaemolytic was decreased by the safflower and linseed oil diets and increased by the fish oil diet, compared with the olive and palm oil diets. Analysis of the fatty acid compositions of the dietary oils on the one hand and of the red cell phospholipids on the other established, specifically, that in the presence of 30 microM chlorpromazine the percentage haemolysis was directly proportional to the linoleate content of the red cell phospholipids.