EFFECTS OF STORAGE ON VENOUS AND CAPILLARY BLOOD-SAMPLES - THE INFLUENCE OF DEFEROXAMINE AND BUTYLATED HYDROXYTOLUENE ON THE FATTY-ACID ALTERATIONS IN RED-BLOOD-CELL PHOSPHOLIPIDS

Fatty acid concentrations in plasma and red blood cell phospholipids i solated from paired venous and capillary blood samples were compared a nd the effect of storage at -20 degrees C was evaluated as well. Plasm a fatty acid profiles from venous and capillary blood were found to be comparable and not affected by up to four weeks of storage, while fat ty acid profiles of venous and capillary red blood cells were no longe r comparable after four weeks. Substantial losses of long-chain polyun saturated fatty acids were observed in capillary red blood cells. To i nvestigate whether the observed long-chain polyunsaturated fatty acids loss could be prevented, capillary red blood samples were stored for up to one year at -50 degrees C in the presence of the iron-binding ag ent deferoxamine or the free radical scavenger butylated hydroxytoluen e. Both compounds protected the long-chain polyunsaturated fatty acids . Similarly, storage of red blood cell lipid extracts at -50 degrees C for up to one year was not associated with reduced levels of long-cha in polyunsaturated fatty acids. In conclusion, the lipid loss from cap illary red blood cells can be reduced for at least one year during sto rage at -50 degrees C with prior addition of either a metal chelating compound or a free radical scavenger, or by preparing lipid extracts o f the samples within one week of blood collection.