Metabolic changes during platelet storage.

Platelet concentrates (PC) were stored in plastic bags with continuous shaking at 4, 22, and 37 C. Various metabolic parameters were examined over a 72-hour period. At 22 C, the pH and PO2 declined over 72 hours while the PCO2 and lactate increased. Hypotonic shock declined to 70 per cent. This differed from the small amounts of CO2 and lactate found at 4 C and the marked accumulation of metabolites and almost complete loss of shock response at 37 C. Aggregation was always better maintained with 4 C storage. The toxic effect of the accumulation of metabolites on the platelets was tested by adding lactate to fresh PC at zero time. This was effective in lowering the initial pH, markedly inhibiting the response to aggregation and decreasing the total accumulation of lactate during storage, but did not produce an inhibition of hypotonic shock response. The effect of accumulation of toxic metabolites was further investigated by using 72-hour plasma and platelets and recombining each of them with fresh preparations. Platelets were tested under degassed conditions to outline the requirements for oxygen and gasious exchange. Surprisingly, there was less accumulation of lactate and CO2 and better hypotonic shock response. These experiments have detected various changes in viability markers in platelets that are stored under actual blood bank conditions and indicate that the accumulation of lactate is not totally responsible for the toxic inhibition of platelet performance that is found upon storage at 22 C.