Chrono-lume ® and Magnesium Potentiate Aggregation of Canine but not Human Platelets in Citrated Platelet-Rich Plasma
Mary Beth Callan (1) , Frances S. Shofer (1) , Carol Wojenski (2) , Urs Giger (1)
From the (1) Department of Clinical Studies, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA, and the (2) Cardeza Foundation and Department of Biochemistry and Molecular Pharmacology, Thomas Jefferson Medical College, Philade
Summary The effects of Chrono-lume ® (CL) and magnesium sulfate (Mg 2+ ), acomponent of this luciferin-luciferase reagent, on platelet aggregationwere studied in platelet-rich plasma (PRP) obtained from blood anti-coagulatedwith sodium citrate from humans, dogs, cats, horses, andcows. The final added Mg 2+ concentration of both solutions rangedfrom 0.75-3.7 mM. CL and Mg 2+ had no effect on maximum aggregationof platelets from humans induced by sub-threshold concentrationsof collagen and ADP. In contrast, addition of CL or Mg 2+ to canine PRPresulted in a dose-dependent and equal potentiation of platelet aggregationin response to sub-threshold concentrations of collagen, ADP, andthrombin in normal and thrombopathic dogs. The effect of CL on plateletaggregation induced by sub-threshold concentrations of agonistswas less pronounced and varied in other species according to theagonist. The reason for the marked difference in sensitivity of humanand canine platelets to CL or Mg 2+ is not clear, although a difference inreleasable cation pools of the platelets from these two species has beenrecognized. Platelet aggregation studies of animals with suspectedthrombopathias should be performed without CL to prevent masking ofa platelet function defect.