Decreased hemolysis and lipid peroxidation in blood during storage in the presence of nicotinic acid

Background and Objectives: There is increase in lipid peroxidation with con sequent increase in hemolysis when blood is stored in di-(2-ethyl hexyl)pht halate (DEHP) plasticized bags. Studies carried out by us and others have i ndicated the ability of red cells to synthesize NAD(+) from added nicotinic acid. Apart from the role of NAD(+) in glycolysis, NADPH is required for r eduction of oxidized glutathione to its reduced form by glutathione reducta se. Reduced glutathione is an important antioxidant, which protects cell me mbrane from oxidative damage. Reduced glutathione is also involved in the r egeneration of vitamin E, another important membrane antioxidant. In view o f these, a study was undertaken to find out the effect of addition of nicot inic acid to the citrate-phosphate-dextrose-adenine (CPDA) solution on lipi d peroxidation and integrity of red cells when whole blood is stored in DEH P plasticized bags. Materials and Methods: Blood was collected in Penpol bl ood storage bags (which is a DEHP plasticized bag) in CPDA solution in the presence and absence of nicotinic acid. Various parameters of lipid peroxid ation and membrane stability - level of malondialdehyde (MDA), conjugated d ienes, vitamin E, reduced glutathione, plasma Hb and K+, levels of adenosin e triphosphate (ATP) and 2,3-diphosphoglycerate (2,3-DPG) were studied in t he blood samples after various periods. Results: Plasma Hb and K+ concentra tions 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-DP G 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 lipi d peroxidation and increases antioxidant protection; (3) maintains pH neare r to 7.0, and (4) decreases the leaching out of DEHP into the blood.