Platelet Adhesion to Subendothelium - Effect of Shear Rate, Hematocrit and Platelet Count on the Dynamic Equilibrium Between Platelets Adhering to and Detaching from the Surface

Summary

The adherence of human ³H-adenine-labeled platelets to rat subendothelium was quantitated using a rotating probe device. Platelet adhesion increased in relation to the rotation time, reaching a plateau value in about 4-6 min without any further increase. A non-linear fitting analysis of experimental data allowed calculations of initial rate and plateau value of platelet adhesion. Increasing the shear rates (from 35 to 150 sec^-1) or the hematocrit (from 10% to 40%), both the adhesion rate and the plateau value were increased. When different platelet concentrations were used the adhesion rate and the plateau calculated increased with platelet concentration. Different plateau values were obtained in the experimental conditions considered. This suggests that the plateau was not reached for the complete occupation of the subendothelial surface by the adherent platelets. Experiments using two different vessels rotated in the same platelet suspension or, viceversa, the same vessel rotated successively in two fresh platelet suspensions, showed that the plateau was not determined by reduced platelet reactivity. Rotating the same vessel first in radiolabeled platelets, until the plateau was reached, and secondly in non labeled platelets, or viceversa, showed that the plateau was indeed a dynamic condition where the number of platelets adhering and detaching reached equilibrium. These observations suggest that the platelet adhesion to subendothelium is the final equilibrium of two platelet fluxes, one adhering to the surface and another detaching from the surface.

keywords

Platelet adhesion - Subendothelium - Blood flow

• References

• 1 Turitto VT, Muggli R, Baumgartner HR. Physical factors influencing platelet deposition on subendothelium. Ann NY Acad Sci USA 1977; 283: 284-92
• 2 Turitto VT, Weiss HJ, Baumgartner HR. Rheological factors influencing platelet interaction with vessel surfaces. J Rheol 1979; 23: 735-49
• 3 Feuerstein IA, Brophy JM, Brash JL. Platelet transport and adhesion to reconstituted collagen and artificial surfaces. Trans Am Soc Artif Intern Organs 1975; 18: 427-435
• 4 Grabowski EF, Friedman LI, Leonard EF. Effects of shear rate on the diffusion and adhesion of blood platelets to a foreign surface. Ind Eng Chem Fundam 1979; 11: 224-232
• 5 Turitto VT, Baumgartner HR. Platelet interaction with subendothelium on a perfusion system: physical role of red blood cells. Microvasc Res 1975; 9: 335-344
• 6 Cazenave JP, Blondowska D, Richardson M, Kinlough-Rathbone RL, Packham MA, Mustard JF. Quantitative radioisotopic measurement and scanning electron microscopic study of platelet adherence to collagen coated surface and to subendothelium with a rotating probe device. J Lab Clin Med 1979; 93: 60-70
• 7 Groves HM, Kinlough-Rathbone RL, Cazenave JP, Dejana E, Richardson M, Mustard JF. Effect of dipyridamole and prostacyclin on rabbit platelet adherence in vitro and in vivo. J Lab Clin Med 1982; 99: 548-559
• 8 Mustard JF, Perry DW, Ardlie NG, Packham MA. Preparation of suspensions of washed platelets from humans. Br J Haematol 1972; 22: 193-204
• 9 Molnar J, Lorand L. Studies on apyrase. Arch Biochem Biophys 1961; 93: 353-362
• 10 Donnelly RJ, Simon NJ. An empirical torque relation for supercritical flow between rotating cylinders. J Fluid Mech 1960; 7: 401-408
• 11 Davey A. The growth of Taylor vortices in flow between rotating cylinders. J Fluid Mech 1962; 14: 336-68
• 12 Bird RB, Stewart WE, Lightfoot EN. Transport phenomena. Wiley, New York, N.Y 1960
• 13 Sacchi G, Landriani G, Guardabasso V, Rocchetti M. NL-FIT: A microcomputer program for non linear fitting. Comput Program Biomed 1983; 16: 35-42
• 14 Turitto VT, Weiss HJ, Baumgartner HR. The effect of shear rate on platelet interaction with subendothelium exposed to citrated human blood. Microvasc Res 1980; 19: 352-65
• 15 Turitto VT, Weiss HJ. Red blood cells: their dual role on thrombus formation. Science 1980; 207: 541-543
• 16 Turitto VT, Benis AM, Leonard EF. Platelet diffusion in flowing blood. Ind Eng Chem Fund 1972; 11: 216-23
• 17 Goldsmith HL. The flow of model particles and blood cells and its relation to thrombogenesis. In Progress in Hemostasis and Thrombosis Spaet TH. (Ed.) Vol 1 Grune & Stratton Inc; New York: 1972. pp 97-139
• 18 Aarts PA M M, Bolhuis PA, Sakariassen KS, Heethaar RM, Sixma JJ. Red blood cell size is important for adherence of blood platelets to artery subendothelium. Blood 1983; 62: 214-7
• 19 Wang NH, Keller KH. Solute transport induced by erythrocyte motion on shear flow. Trans Am Soc Artif Intern Organs 1979; 25: 14-8
• 20 Cazenave JP, Packham MA, Davies JA, Kinlough-Rathbone RL, Mustard JF. Studies of platelet adherence to collagen and the subendothelium. In Platelet Function Testing Day HJ, Holmsen H, Zucker M B. (Eds.) U.S. Department of Health, Education and Welfare; Public Health Service - National Institute of Health: 1976. pp 181-98
• 21 Baumgartner HR, Muggli R. Adhesion and aggregation: morphological demonstration and quantitation in vivo and in vitro. In Platelets in Biology and Pathology Gordon JL. Ed Elsevier/North-Holland Biomedical Press; Amsterdam: 1976: 23-60
• 22 Groves HM, Kinlough-Rathbone RL, Richardson M, Moore S, Mustard JF. Platelet interaction with damaged rabbit aorta. Lab Invest 1979; 40: 194-200