Changes in substances affecting the central nervous system in stored blood products Ⅱ. Analysis of guanidino compounds in blood products

Guanidino compounds in blood products, including red cell concentrate, platelet concentrate and liquid plasma, were fluorometrically analyzed with a guanidino compound analyzer. Highly toxic guanidino compounds such as methylguanidine and guanidinosuccinic acid were not found in any blood product under usual storage conditions. The levels of guanidinoacetic acid and creatinine in these products changed little during storage. On the other hand, the concentration of arginine decreased markedly over storage time and reached approximately 20% of the initial value after 7 days of storage. Addition of arginine at a final concentration of 1mmol/l to the red cell concentrate resulted in better maintenance of the 2,3-DPG level and morphology score of red cells. Moreover, arginine showed a protecting effect against hemolysis. These data indicate that adverse reactions due to guanidino compounds may be neglected in blood transfusion, and that arginine should be useful as a blood preservative.