Effect of diltiazem and a prostaglandin derivative (PGBx) on platelet function during long-term storage

Calcium is an intermediate messenger between platelet stimuli and platelet response. Published studies have shown that the decreased ability of platelets to control calcium flux during long-term storage leads to platelet senility. Platelet metabolism might be more efficient during storage if pharmacologic agents that limit calcium movement were incorporated into the platelet concentrate storage solution. This hypothesis was tested by storing platelets with the calcium channel blocker, diltiazem, or with a prostaglandin B1 derivative, PGBx. During a 15-day storage period, platelets incubated with either diltiazem or PGBx showed improved function, as measured by aggregation, as compared to control platelets. The PGBx -enhanced platelet function during storage was accompanied by a significant decrease in glucose and an increase in adenosine triphospate concentrations. Platelet function after storage with PGBx improved in spite of significantly lower pH levels of the platelet concentrates at all time points tested. These studies suggest that the maintenance of calcium ion homeostasis during long-term platelet storage is important to in vitro platelet function even if the Ca2+ balance is maintained at the expense of pH and the glucose concentrations.