Accession Number : AD0293169

Title :   STUDIES OF PLATELETS

Corporate Author : GEORGE WASHINGTON UNIV WASHINGTON D C

Personal Author(s) : RHEINGOLD,JACK J. ; ADELSON,EDWARD ; LEAR,ARNOLD A.

Report Date : 30 DEC 1962

Pagination or Media Count : 1

Abstract : A technique was devised for obtaining a cohort of tagged young platelets in dogs. These studies reveal that dog platelets are randomly destroyed by the process of continuous in vivo coagulation. This process results in a half-life of 1.5 days. Dog platelets begin to die by aging when they reach 8 days, and no platelets survive beyond 12 days of age. However, in the normal dog less than two percent of the platelets survive theANDOM PROCESS OF DESTRUCTION FOR 8 DAYS SO THAT AGING PLAYS A NEGLIGIBLE ROLE IN DETERMINING PLATELET SURVIVAL. Neither warfarin nor heparin is able completely to stop the process of in vivo coagulation. Of the two, however, heparin appears to be more effective in dogs. A comparable study in humans reveals a similar random process of platelets destruction by continuous in vivo coagulation. The half-life of this process is 2.8 days. Senescence for human platelets begins on day 10 and is complete by day 15. Less than 3% of human platelets survive to day 10 and senescence. Heparin slows the random process of platelet destruction from the normal half-life of 2.8 days to a half-life of 7 days. (Author)

Descriptors :   *BLOOD PLATELETS, AGING (PHYSIOLOGY), COAGULATION, DOGS, DRUGS, HEPARIN, INHIBITION, LABELED SUBSTANCES, HUMANS, RADIOACTIVE ISOTOPES, THROMBOSIS

Distribution Statement : APPROVED FOR PUBLIC RELEASE