Decreased Hemolysis and Lipid Peroxidation in Blood during Storage in the Presence of Nicotinic Acid

Abstract

Background and Objectives: There is increase in lipid peroxidation with consequent increase in hemolysis when blood is stored in di–(2–ethyl hexyl)phthalate (DEHP) plasticized bags. Studies carried out by us and others have indicated the ability of red cells to synthesize NAD⁺ from added nicotinic acid. Apart from the role of NAD⁺ in glycolysis, NADPH is required for reduction of oxidized glutathione to its reduced form by glutathione reductase. Reduced glutathione is an important antioxidant, which protects cell membrane from oxidative damage. Reduced glutathione is also involved in the regeneration of vitamin E, another important membrane antioxidant. In view of these, a study was undertaken to find out the effect of addition of nicotinic acid to the citrate–phosphate–dextrose–adenine (CPDA) solution on lipid peroxidation and integrity of red cells when whole blood is stored in DEHP plasticized bags. Materials and Methods: Blood was collected in Penpol blood storage bags (which is a DEHP plasticized bag) in CPDA solution in the presence and absence of nicotinic acid. Various parameters of lipid peroxidation and membrane stability – level of malondialdehyde (MDA), conjugated dienes, vitamin E, reduced glutathione, plasma Hb and K⁺, levels of adenosine triphosphate (ATP) and 2,3–diphosphoglycerate (2,3–DPG) were studied in the blood samples after various periods. Results: Plasma Hb and K⁺ concentrations were significantly lower in the presence of added nicotinic acid both after 28 and 42 days. Concentration of MDA and conjugated dienes was lower and the levels of reduced glutathione and vitamin E higher in the presence of nicotinic acid. ATP levels were not significantly different, but 2,3–DPG levels were higher. pH of the blood was nearer to 7.0 in the presence of nicotinic acid, while leaching out of DEHP into the blood was significantly lower. Conclusion: Inclusion of nicotinic acid in the CPDA solution has a beneficial effect in that (1) it reduces plasma Hb and K⁺; (2) reduces lipid peroxidation and increases antioxidant protection; (3) maintains pH nearer to 7.0, and (4) decreases the leaching out of DEHP into the blood.