Accession Number : ADA955150

Title :   Human Platelet Senescence.

Descriptive Note : Annual summary rept. no. 1, 31 Jul 68-30 Jun 69,

Corporate Author : NEW YORK UNIV MEDICAL CENTER N Y

Personal Author(s) : Karpatkin,Simon

Report Date : 30 JUN 1969

Pagination or Media Count : 4

Abstract : In a previous communication, evidence was cited for the complications of massive blood transfusions during shock or hemorrhage. These transfusions are often complicated with severe hemorrhagic problems secondary to the loss of viable platelets (necessary for the maintenance of hemostasis) secondary to storage of bank blood. Thus recipients are transfused with blood depleted of viable platelets and hemorrhagic problems as well as death ensue. Evidence which strongly suggests the existence of human platelet senescence, heretofore seriously questioned has been accumulated. Human platelets from healthy donors have been separated into extreme density-volume populations by centrifugation in relatively inert specific density media. A large-heavy platelet population has been separated which appears to be the young platelet and a light-small platelet population has been separated which appears to be the old platelet. The large-heavy platelet population studied is approximately 2.4 times the volume of the light-small platelet population studied and is more active metabolically. These data suggest a greater metabolic advantage for large-heavy platelets in their ability to maintain and store high energy phosphates (as well as a greater functional capacity). These high energy phosphates are required for the maintenance of ionic gradients between the intra- and extracellular platelet environment.

Descriptors :   AGING(PHYSIOLOGY), BLOOD, BLOOD CIRCULATION, BLOOD PLATELETS, BLOOD TRANSFUSION, CAPACITY(QUANTITY), CONSTRICTIONS, DEATH, DENSITY, ENVIRONMENTS, HEMORRHAGE, HIGH ENERGY, HUMANS, INERT MATERIALS, MAINTENANCE, MEDIA, PHOSPHATES, STORAGE, VASOCONSTRICTING, VIABILITY

Subject Categories : Anatomy and Physiology
      Medicine and Medical Research

Distribution Statement : APPROVED FOR PUBLIC RELEASE