ristocetin and leupeptin

Platelets stored in CLX blood bags, under normal blood banking conditions, were studied for up to 7 days to determine if changes occurred in the levels of membrane glycoproteins (GP) Ib-IX and IIb-IIIa. Radiolabeled monoclonal antibodies (MAB) were used to estimate the number of glycoprotein molecules on the surface membrane of intact platelets. GP IX and GP IIb-IIIa levels remained essentially unaltered during storage. In contrast, the content of GP Ib at day 7 decreased by 45% of the total when fresh. The aggregation response to ristocetin, which requires GP Ib, was also diminished after 7 days. Addition of protease inhibitors, leupeptin and/or aprotinin did not appear to influence the degradation of this glycoprotein. We conclude that storage at 22 degrees C had deleterious effects on the GP Ib content of platelets.

Topics: Antibodies, Monoclonal; Aprotinin; Blood Platelets; Blood Preservation; Cold Temperature; Humans; Leupeptins; Platelet Aggregation; Platelet Glycoprotein GPIb-IX Complex; Platelet Membrane Glycoproteins; Ristocetin