Effects of postprandial plasma and chylomicrons on endothelial cells. Differences between dietary cream and cod liver oil.

The acute effects of fatty meals (900 kcal) rich in saturated (cream) or n-3 polyunsaturated (cod liver oil, CLO) fatty acids on human umbilical vein endothelial cells (ECM) and platelet behavior were studied. The ECM were incubated for 24 hours at 37 degrees C with either plasma or chylomicrons (CM) obtained 3 hours after the meals. The ability of the ECM to inhibit platelet aggregation (PIA) and the release of prostaglandin I2 measured as 6-keto-prostaglandin F1 alpha (6-keto-PGF1 alpha) were measured after 24 hours of incubation, after stimulation and after freezing and thawing. Similar studies were done with CM from a patient with type V hyperlipoproteinemia. The release of 6-keto-PGF1 alpha was increased by postprandial plasma and by CM obtained after both meals. Plasma collected after CLO, but not after cream, increased PIA, whereas CM derived from all sources studied stimulated the PIA of ECM. No consistent correlation could be established between the release of 6-keto-PGF1 alpha and PIA. Increased platelet aggregation in platelet-rich plasma was always observed during postprandial hyperlipidemia.