HOW HARMLESS IS FFA ENHANCEMENT

Standard heparin as well as low molecular weight heparin (LMWH) increa se lipid levels in serum. It has been reported that a diet rich in lon g chain saturated fatty acids can enhance the susceptibility to experi mental thrombosis. The mechanism by which serum fatty acids may provok e thrombosis is not clear. It is possible that the fatty acids change the properties of the cell membrane and thereby modify the response of platelets to aggregating agents. Heparin and its LMW fractions, by mo bilising lipoprotein lipase that hydrolyses serum triglycerides (TG), cause the serum TG to increase, a well known 'clearing effect' of hepa rin in turbid lipemic plasma. This effect may have no significance whe n it lasts for a short time; however, a long-lasting heparin effect on TG serum levels may have important consequences. The purpose of this study was to examine the time span of the action of heparin and its fr actions and to investigate variations in the concentration of digoxin, which is a compound with narrow therapeutic width. The investigated s ubstances after 2 days administration, provoked serum concentration in creases of free fatty acids (FFA), TG and HDL-C. Seven days after stop ping drug administration, FFA and HDL-C levels remained high, while tr iglycerides declined. Serum total cholesterol remained unchanged throu ghout. Digoxin levels increased non-significantly after heparin admini stration and during swimming stress, while a lipid diet caused a serum digoxin concentration increase.