Kie Horioka1, Hiroki Tanaka2, Shotaro Isozaki3, Hiroaki Konishi4, Lynda Addo5, Shuhei Takauji6, Henrik Druid1. 1. Department of Oncology-Pathology, Karolinska Institutet, Stockholm, Sweden. 2. Division of Tumor Pathology, Department of Pathology, Asahikawa Medical University, Japan. Electronic address: hiroki-t@asahikawa-med.ac.jp. 3. Division of Gastroenterology and Hematology/Oncology, Department of Medicine, Asahikawa Medical University, Japan. 4. Department of Gastroenterology and Advanced Medical Sciences, Asahikawa Medical University, Japan. 5. School of Biomedical and Allied Health Sciences, University of Ghana, Ghana. 6. Division of Gastroenterology and Hematology/Oncology, Department of Medicine, Asahikawa Medical University, Japan; Department of Emergency Medicine, Asahikawa Medical University, Japan.
Abstract
BACKGROUND: Hypothermia triggers coagulation, which can lead to the development of a life-threatening condition. We previously reported that hypothermia induces platelet activation in the spleen, resulting in microthrombosis after rewarming. However, the changes in whole blood clotting properties that occur remain unclear. Using thromboelastography, we investigated blood clotting activity and the effects of rewarming in a murine model of hypothermia. METHODS: C57Bl/6 mice were exposed to an ambient temperature of -20 °C under general anesthesia until their rectal temperature decreased to 15 °C. One group of mice was kept at 4 °C for 2 h and then euthanized. Another group was rewarmed, kept in normal conditions for 24 h, and then euthanized. Tissue and citrated whole blood samples were obtained from the mice for histopathological analysis, flow cytometry, and thromboelastography. RESULTS: Hypothermia induced the activation of platelets in the spleen; however, rewarming significantly reduced the number of activated platelets in the spleen while their numbers significantly increased in peripheral blood. In hypothermic mice not subjected to rewarming, no increase in activated platelets was observed in peripheral blood. Thromboelastography analysis showed that whole blood samples from the rewarmed mice displayed an enhanced clotting strength. CONCLUSIONS: Rewarming from hypothermia enhances whole blood coagulation activity accompanied by an increase in the number of active platelets in peripheral blood. This phenomenon may lead to formation of microthrombi and thrombotic disorders.
BACKGROUND:Hypothermia triggers coagulation, which can lead to the development of a life-threatening condition. We previously reported that hypothermia induces platelet activation in the spleen, resulting in microthrombosis after rewarming. However, the changes in whole blood clotting properties that occur remain unclear. Using thromboelastography, we investigated blood clotting activity and the effects of rewarming in a murine model of hypothermia. METHODS: C57Bl/6 mice were exposed to an ambient temperature of -20 °C under general anesthesia until their rectal temperature decreased to 15 °C. One group of mice was kept at 4 °C for 2 h and then euthanized. Another group was rewarmed, kept in normal conditions for 24 h, and then euthanized. Tissue and citrated whole blood samples were obtained from the mice for histopathological analysis, flow cytometry, and thromboelastography. RESULTS:Hypothermia induced the activation of platelets in the spleen; however, rewarming significantly reduced the number of activated platelets in the spleen while their numbers significantly increased in peripheral blood. In hypothermicmice not subjected to rewarming, no increase in activated platelets was observed in peripheral blood. Thromboelastography analysis showed that whole blood samples from the rewarmed mice displayed an enhanced clotting strength. CONCLUSIONS: Rewarming from hypothermia enhances whole blood coagulation activity accompanied by an increase in the number of active platelets in peripheral blood. This phenomenon may lead to formation of microthrombi and thrombotic disorders.
Authors: Torstein Schanche; Ole Magnus Filseth; Bjarne Østerud; Timofei V Kondratiev; Gary C Sieck; Torkjel Tveita Journal: Front Physiol Date: 2022-04-29 Impact factor: 4.755