Platelet Factor 3 Activity in Washed Platelets

Summary

Platelets collected with an EDTA solution and simply washed in an incomplete Tyrode’s presented clotting times in the recalcification (man and rat) and the Stypven (rat) tests that were practically identical to those of the PRP when slow speed centrifugation was used (800 G in man, 1000 G in rat). This was demonstrated, in 6 pools of 5 rats each and in 6 men, by comparing the clotting activity of the citrated platelet-rich plasma to that of the platelets washed and resuspended in the citrated platelet-poor plasma, for platelet counts ranging from 1 × 10⁵ to 10 × 10⁵/mm³. In contrast, centrifugation of platelets at 3000 G markedly affected these clotting activities, as was shown in an additional study comprising 6 pools of 3 rats.

Finally, the clotting activity of platelets totally disrupted by sonication appears to be identical quantitatively in both man and rats to that of the total phospholipids extracted from these platelets and separated from the other lipids by thin-layer chromatography and resuspended in plasma by sonication.

^* Present address: Directeur, INSERM, Unité 63, 22, Avenue du Doyen Lépine, 69500 Lyon-Born-France.

• References

• 1 Biggs R, Denson K. W. E, Riesenberg D, and McIntyre C. 1968; The coagulant activity of platelets. British Journal of Haematology 15: 283.
• 2 Folch J, Lees M, and Sloane Stanley G. H. 1957; A simple method for the isolation and purification of total lipids from animal tissues. Journal of Biochemistry 226: 497.
• 3 Hardisty R. M, and Hutton R. A. 1965; The kaolin clotting time of platelet-rich plasma: a test of platelet factor 3 availability. British Journal of Haematology 11: 258.
• 4 Marcus A. J, Ullman H. L, Safier L. B, and Ballard H. S. 1962; Platelet phosphatides. Their fatty acid and aldehyde composition and activity in different clotting systems. Journal of Clinical Investigation 41: 2198.
• 5 Pool J. G, and Robinson A. J. 1971; A change in Russell’s viper venom (Stypven): modification of factor V assay to compensate. Journal of Laboratory and Clinical Medicine 77: 343.
• 6 Poole J. C. F, and Robinson D. S. 1956; A comparison of the effects of certain phosphatides and of chylomicra on plasma coagulation in the presence of Russell’s viper venom. Quarterly Journal of Experimental Physiology 41: 31.
• 7 Renaud S. 1969; The recalcification plasma clotting time. A valuable general clotting test in man and rats. Canadian Journal of Physiology and Pharmacology 47: 689.
• 8 Renaud S, Kinlough R, and Mustard J. F. 1970; Relationship between platelet aggregation and the thrombotic tendency in rats fed hyperlipemic diets. Laboratory Investigation 22: 339.
• 9 Renaud S, and Lecompte F. 1970; Hypercoagulability induced by hyperlipemia in rat, rabbit and man. Role of platelet factor 3. Circulation Research 27: 1003.
• 10 Spaet T. H, and Cintron J. 1965; Studies on platelet factor 3 availability. British Journal of Haematology 11: 269.
• 11 Troup S. B, Reed C. F, Marinetti G. V, and Swisher S. N. 1960; Thromboplastic factors in platelets and red blood cells : observations on their chemical nature and function in in vitro coagulation. Journal of Clinical Investigation 39: 342.
• 12 Walsh P. N. 1972; Albumin density gradient separation and washing of platelets and the study of platelet coagulant activities. British Journal of Haematology 22: 205.