Platelet consumption by polyvinyl alcohol coated tubing in canines

Polyvinyl alcohol (PVA)-coated polyethylene tubing, with or without immobilized heparin, caused severe thrombocytopenia and enhanced the production of new platelets when inserted in a chronic arteriovenous shunt in canines. A similar length of uncoated polyethylene tubing neither lead to thrombocytopenia nor significantly enhanced platelet regeneration, relative to the shunt only without a test section. Platelet regeneration was monitored by the malondialdehyde assay, which was assumed to make a distinction between "new" and "old" platelets. This distinction was combined with the platelet count values to enable calculation of the cumulative consumption curve and the initial fractional consumption rate in the presence of a non constant platelet count. The resulting initial fractional consumption rates were: 34%/day for PVA, 20.5%/day for polyethylene, and 18%/day for the shunt only blank.