Effect of forskolin on the maintenance of platelet properties during storage

During storage of platelet concentrates under routine blood banking conditions a gradual increase takes place in the degree of platelet activation. Studies were designed to determine whether the addition of forskolin, a direct activator of platelet adenylate cyclase and inhibitor of platelet activation, could reduce some of the deleterious changes occurring during a 10-day storage period at 20 degrees to 24 degrees C. Forskolin was added to the platelet-rich plasma before preparation of the platelet concentrates. Dose-effect studies in which 0.5, 5, and 50 mumol/L forskolin were compared indicated that 5 mumol/L forskolin was the optimal concentration for the reduction of platelet activation over this period as assessed by measuring the release of beta-thromboglobulin and the formation of thromboxane B2. It was determined that cyclic adenosine monophosphate levels were increased approximately fourfold by 5 mumol/L forskolin and maintained at a high level for at least the first 48 hours. These results show that the presence of forskolin inhibits the activation of platelets during storage.