The contribution of platelets and the vessel wall to the antithrombotic effects of a single intravenous bolus injection of 0.8 mg/kg Fab fragments of the monoclonal antiplatelet glycoprotein Hb/IIIa receptor antibody 7E3 (7E3-Fab), combined with continuous heparin anticoagulation (100 U/kg bolus and 50 U/kg per hour), was studied in a canine preparation consisting of an everted (inside out) carotid arterial segment that had been inserted into a transected femoral artery. In all 6 control dogs without antibody, persistent or transient eversion graft occlusion occurred during an initial 2-hour observation period, and 5 of the 6 grafts were occluded at 24 hours. In 6 dogs given 7E3-Fab 24 hours before receiving an everted carotid artery segment from a donor dog, cyclic occlusion and reflow occurred in all dogs, whereas the grafts were patent at the end of a 2-hour observation period in 5 of the 6 dogs (P=.056 versus control). When transferred back to the donor dogs, the patent eversion segments showed brief periods of cyclic occlusion and reflow within 2 hours in 3 of 5 dogs (P=.034 versus control), whereas all of the 5 eversion segments were patent at 24 hours (P<.005 versus control). When platelet concentrates (prepared 48 hours after injection of the antibody fragment from approximately 50% of the blood volume of the dogs given 7E3-Fab) were transfused into animals with eversion grafts 10 minutes before vessel clamp release, persistent or transient occlusion was observed within 2 hours in all 5 dogs (P=not significant versus control), but 4 of these 5 grafts were patent at 24 hours (P=.045 versus control). ADP-induced platelet aggregation and bleeding times remained normal throughout the eversion grafting experiments in all dogs. Thus, long-term or even short-term exposure of eversion grafts to platelets treated with 7E3-Fab conferred reduced thrombogenicity.
|Number of pages||6|
|Journal||Arteriosclerosis, thrombosis, and vascular biology|
|Publication status||Published - jan. 1 1994|
ASJC Scopus subject areas
- Cardiology and Cardiovascular Medicine