CHARACTERIZATION OF PLATELETS ISOLATED FROM MICE FED DIETS CONTAINING TRANS FATTY ACIDS

Positional and geometrical fatty acid isomers, primarily trans-octadecenoates (t-18:1), derived from partially hydrogenated fats, were administered in utero and throughout life, to mice as 0.0, 5.3, 8.4, or 10.6% of the total calories of a nutritionally adequate diet.;Trans-18:1 and t-16:1 isomers were incorporated in platelet ester- and ether-linked lipids of animals fed diets containing trans fatty acids. Those trans fatty acid containing platelet lipids had reduced percentages of 16:0, 18:0, cis-18:1 and 22:6(n-3) and increased percentages of 18:2(n-6) and 18:3(n-3) fatty acids. The levels of 20:4(n-6) were constant regardless of the amount of trans fatty acids in the diet. When trans isomers were calculated as saturated fatty acids, levels of saturated, monounsaturated and polyunsaturated fatty acids in platelet lipids isolated from animals on each of the diets were also similar.;Compared to platelets isolated from animals fed the control diets (0.0% trans fatty acid diets), those isolated from animals fed the experimental diets had increased percentages of phosphatidylserine. Platelets isolated from animals fed trans fatty acids as 5.3 and 10.6 percent of the total calories also had increased percentages of phosphatidylinositol and decreased percentages of sphingomyelin. Protein, phospholipid and cholesterol levels of platelets isolated from mice fed 5.3 and 10.6% of the total calories were not significantly different from those of platelets isolated from mice fed the control diets.;The platelet concentrations in whole blood, and bleeding times of mice were measured and found to be unaltered by the experimental diets. Size distributions, membrane fluidities and ADP-induced aggregations of platelets isolated from mice fed the trans fatty acids as 5.3 and 10.6% of the total calories were measured and also found to be unaltered compared to those of platelets isolated from mice fed the control diets.;Mouse platelets were characterized with regard to protein, phospholipid and cholesterol levels and phospholipid class, fatty acid and dimethyl acetal profiles. These parameters were very similar to those reported for human platelets.;Data obtained are consistent with the hypotheses that trans isomers partially replace saturated fatty acids in platelet lipids and perturb the desaturation and elongation of essential fatty acids.