BIOTINYLATED PLATELETS HAVE AN IMPAIRED RESPONSE TO AGONISTS AS EVIDENCED BY IN-VITRO PLATELET-AGGREGATION TESTS

Biotinylation of platelets, using a water soluble biotin analogue whic h reacts with primary amines, has been proposed to be a reliable techn ique for study of in vivo survival of platelets and their subpopulatio ns. The information about the influence of this technique on platelet function has been limited. In the present work we studied the effect o f in vitro biotinylation on platelet function and activation, Washed h uman platelets, at a concentration of 1x10(9)/L, were biotinylated wit h five different concentrations of sulfo-NHS-biotin or NHS-LC-biotin, ranging from 0 to 5 mM. The degree of platelet activation during and a fter biotinylation was monitored by measuring the externalization of P -selectin, and the platelet function was evaluated by aggregometry. It was observed that biotinylated platelets, in a dose dependent dent ma nner, displayed an impaired aggregation response. A slight increase in platelet membrane P-selectin occurred during the labelling procedure. (C) 1998 Elsevier Science Ltd.