Accession Number : ADA628235


Title :   Effects of Low Temperature on Shear-Induced Platelet Aggregation and Activation


Descriptive Note : Journal article


Corporate Author : ARMY INST OF SURGICAL RESEARCH FORT SAM HOUSTON TX


Personal Author(s) : Zhang, Jian-ning ; Wood, Jennifer ; Bergeron, Angela L ; McBride, Latresha ; Ball, Chalmette ; Yu, Qinghua ; Pusiteri, Anthony E ; Holcomb, John B ; Dong, Jing-fei


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a628235.pdf


Report Date : Aug 2004


Pagination or Media Count : 9


Abstract : Background: Hemorrhage is a major complication of trauma and often becomes more severe in hypothermic patients. Although it has been known that platelets are activated in the cold, studies have been focused on platelet behavior at 4 degrees C, which is far below temperatures encountered in hypothermic trauma patients. In contrast, how platelets function at temperatures that are commonly found in hypothermic trauma patients (32 37 degrees C) remains largely unknown, especially when they are exposed to significant changes in fluid shear stress that could occur in trauma patients due to hemorrhage, vascular dilation/constriction, and fluid resuscitation. Methods: Using a cone-plate viscometer, we have examined platelet activation and aggregation in response to a wide range of fluid shear stresses at 24, 32, 35, and 37 degrees C. Results: We found that shear-induced platelet aggregation was significantly increased at 24, 32, and 35 degrees C as compared with 37 degrees C and the enhancement was observed in whole blood and platelet-rich plasma. In contrast to observation made at 4 degrees C, the increased shear-induced platelet aggregation at these temperatures was associated with minimal platelet activation as determined by the P-selectin expression on platelet surface. Blood viscosity was also increased at low temperature and the changes in viscosity correlated with levels of plasma total protein and fibrinogen. Conclusion: We found that platelets are hyper-reactive to fluid shear stress at temperatures of 24, 32, and 35 degrees C as compared with at 37 degrees C. The hyperreactivity results in heightened aggregation through a platelet-activation independent mechanism. The enhanced platelet aggregation parallels with increased whole blood viscosity at these temperatures, suggesting that enhanced mechanical cross-linking may be responsible for the enhanced platelet aggregation.


Descriptors :   *BLOOD PLATELETS , *LOW TEMPERATURE , BEHAVIOR , BLOOD CIRCULATION , BLOOD PLASMA , BLOOD VOLUME , BODY TEMPERATURE , CARDIOVASCULAR SYSTEM , CROSSLINKING(CHEMISTRY) , EMERGENCY MEDICINE , EXPOSURE(PHYSIOLOGY) , FLUIDS , GLYCOPROTEINS , HEMORRHAGE , HYPOTHERMIA , OPTIMIZATION , PATIENTS , RESPONSE(BIOLOGY) , RESUSCITATION , SHEAR STRESSES , TRAUMA , VISCOSITY , WOUNDS AND INJURIES


Subject Categories : Biochemistry
      Anatomy and Physiology
      Medicine and Medical Research


Distribution Statement : APPROVED FOR PUBLIC RELEASE