Platelet adhesion and aggregation on human type VI collagen surfaces under physiological flow conditions.

TitlePlatelet adhesion and aggregation on human type VI collagen surfaces under physiological flow conditions.
Publication TypeJournal Article
Year of Publication1995
AuthorsRoss JM, McIntire LV, Moake JL, Rand JH
Date Published1995 Apr 01
KeywordsAnimals, Antibodies, Monoclonal, Aurintricarboxylic Acid, Cattle, Collagen, Heparin, Humans, Image Processing, Computer-Assisted, Platelet Adhesiveness, Platelet Aggregation, Platelet Membrane Glycoproteins, Rheology, Stress, Mechanical, Swine, von Willebrand Diseases, von Willebrand Factor

Type VI collagen is a subendothelial constituent that binds von Willebrand factor (vWF) and platelets. The interaction of platelets with type VI collagen and the roles of platelet glycoprotein (GP) receptors and vWF were studied under flow conditions using epi-fluorescent videomicroscopy coupled with digital image processing. We found that surface coverage was less than 6% on collagen VI at a relatively high-wall shear rate (1,000 s-1) and was approximately 60% at a low-wall shear rate (100 s-1). The molecular mechanisms involved in low-shear platelet binding were studied using monoclonal antibodies to platelet GPIb and GPIIb-IIIa, and polymeric aurin tricarboxylic acid. Anti-GPIIb-IIIa was the most effective in eliminating adhesion (surface coverage, 0.8%), followed by anti-GPIb (4.3%), and ATA (12.6%). Experiments with von Willebrand disease blood indicate that vWF is involved in platelet adhesion to collagen VI at 100 s-1. In the absence of vWF, there may be direct binding of platelet GPIIb-IIIa complexes to collagen VI. Adhesion and aggregation on collagen VI are different in shear rate dependence from collagen I. Our results suggest a possible role for collagen VI and vWF in platelet adhesion and aggregation in vascular regions with low shear rates.

Alternate JournalBlood
PubMed ID7703489
Grant ListHL-18672 / HL / NHLBI NIH HHS / United States
HL-32200 / HL / NHLBI NIH HHS / United States
NS-23327 / NS / NINDS NIH HHS / United States
Related Faculty: 
Jacob H. Rand, M.D.

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