Experimental Modification of the Platelet Release Reaction Induced by Collagen

Collagen-induced release of platelet constituents can be divided into two kinetically-distinct phases, only one of which is associated with platelet aggregation, and the aggregation-independent release is less susceptible to inhibition by pharmacological agents (Drummond and Gordon, 1974). Minor variations in experimental conditions alter the release reaction profile. Collagen was incubated with platelet rich plasma (PRP) for one minute at 37°, under conditions in which no aggregation occurred ( + 3nM EDTA or in absence of stirring). The reaction was ‘terminated’ by addition of ice-cold EDTA-saline and samples were then centrifuged (14,800 g) under the conditions described in the table.

No significant release was detected under any of the above conditions if saline were substituted for collagen suspension.

These results indicate that the storage temperature and time after centrifugation are as important as the centrifugation conditions themselves, and suggest reasons for discrepancies reported in previous studies of collagen induced release kinetics.

Drummond, A. H. and Gordon, J. L. (1974). Brit. J. Pharmacol. 52, 130 P.