Hemostatic Function, Survival, and Membrane

Received for publication 18 May 1981 and in revised form 20 July 1981. A preliminary report of this work was presented to the 22nd Annual Meeting of the American Society of Hematology in New Orleans, La., December 1978 and has appeared in abstract form. Blood. 52(Suppl.): 159. J. Clin. Invest. The American Society for Clinical Investiga was 28.8 h; of young platelets, 87.4 h; and of normally circulating heterogeneous platelets, (normal platelets) 53.0 h. Notably, the survival of old platelets was found to be exponential, and of young platelets, linear. Analysis of the membrane glycoproteins in young, old and normal platelets indicated that there was no qualitative difference amongst the young, normal, and old platelets. The relative relationship among all the glycoprotein peaks was equal and the only changes observed were quantitative, with young platelets having significantly more membrane glycoprotein per cell than old platelets and normal platelets. Normal platelets had intermediate concentrations of each glycoprotein. These results demonstrate that young platelets are hemostatically more effective in vivo than old platelets. The data are compatible with the hypothesis that platelets age in the circulation by losing membrane fragments and then after becoming senescent, are removed from the circulation by a random