Platelet storage: an assessment of the requirements for plasma and oxygen.

Platelets from several units of plasma were pooled, and then resuspended either as platelet concentrate (PC) (60 ml) or as platelet rich plasma (PRP) (220 ml) and followed during 72 hours of storage at 22 C. Aggregation, pH, and hypotonic shock response are better maintained in the larger volume of plasma. However the decreased pH and function in the PC is not the result of lactate production. While the relative concentration, expressed in mg/dl, is higher in the PC, the absolute production per platelet and, therefore, the total amount of lactate is higher in PRP. Glucose levels are always sufficiently high to permit glucose to be used as a metabolic substrate even after 72 hours. PC maintained in nitrogen have better in vitro function than do platelets stored either in oxygen or CO2. CO2 can easily diffuse through the plastic bag; the same is not true of oxygen. Less than 15 per cent of the volume of oxygen introduced into the bag passed out through the PVC plastic over a 72-hour period. The data suggest that during storage, anaerobic glycolysis is the preferred metabolic route. The relatively poor performance of the PC maybe the result of limitation of some unidentified substrate or cofactor which is present in plasma and which is necessary for maintaining function.