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A Microfluidic Flow Chamber Model for Platelet Transfusion and Hemostasis Measures Platelet Deposition and Fibrin Formation in Real-time
Published on: February 14, 2017
Hemostatic function, survival, and membrane glycoprotein changes in young versus old rabbit platelets
The Journal of Clinical Investigation
|November 1, 1981
Summary
Young platelets are more effective in stopping bleeding than old platelets in vivo. This study in rabbits shows young platelets have longer survival and better hemostatic function, supporting the aging platelet hypothesis.
Area of Science:
- Hematology
- Thrombosis and Hemostasis
- Cellular Aging
Background:
- In vitro studies suggest functional differences between young and old platelets.
- In vivo differences in platelet function and survival have not been clearly established.
- Understanding platelet aging is crucial for hemostasis and thrombosis research.
Purpose of the Study:
- To investigate the in vivo hemostatic function of young versus old platelets in rabbits.
- To determine and compare the survival times of young and old platelets.
- To explore the relationship between platelet age, size, and hemostatic efficacy.
Main Methods:
- Irradiation-induced thrombocytopenia in rabbits to generate populations of young and old platelets.
- Measurement of hemostatic function via serial ear bleeding times.
- Platelet survival studies using radiolabeled platelets reinjected into recipient animals.
- Analysis of platelet size and membrane glycoprotein content.
Main Results:
- Old platelets were smaller (3.84 µm³) than young platelets (5.86 µm³).
- Young platelets demonstrated significantly greater hemostatic effectiveness, resulting in shorter bleeding times at comparable platelet counts (P < 0.001).
- Mean survival time for old platelets was 28.8 h (exponential decay), compared to 87.4 h for young platelets (linear decay).
- Young platelets had higher membrane glycoprotein concentrations per cell than old platelets.
Conclusions:
- Young platelets are demonstrably more effective in vivo hemostasis than aged platelets.
- Platelet aging in circulation may involve loss of membrane fragments, leading to senescence.
- Senescent platelets appear to be removed from circulation via a random process.
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