Seasonal variation in blood viscosity of the hibernating arctic ground squirrel (Spermophilus undulatus plesius)

Effects of Age and Season on Blood Parameters of Captive Giant Pandas: A Pilot Study

“…Therefore, the main reason for increased whole blood viscosity may be due to red blood cell aggregation. Studies have shown that ambient temperature (climate) has an effect on both blood viscosity and plasma viscosity in animals [18][19][20][21]. When the temperature decreases, blood flow slows down, blood viscosity increases, and red blood cell aggregation is enhanced [22][23][24].…”

Effects of Age and Season on Blood Parameters of Captive Giant Pandas: A Pilot Study

“…Therefore, the main reason for increased whole blood viscosity may be due to red blood cell aggregation. Studies have shown that ambient temperature (climate) has an effect on both blood viscosity and plasma viscosity in animals [18][19][20][21]. When the temperature decreases, blood flow slows down, blood viscosity increases, and red blood cell aggregation is enhanced [22][23][24].…”

Hibernation and hemostasis

“…As expected, blood pressure also drops from 140/100 mmHg to 60/30 mmHg, with values as low as 10 mmHg reported ( Lyman and O’brien 1960 ). Thus hibernation entails periods of prolonged immobility ( Carey et al, 2003 ; Utz et al, 2009 ) with low blood flow (stasis) in veins and atria ( Horwitz et al, 2013 ), increased blood viscosity ( Kirkebo, 1968 ; Halikas and Bowers, 1973 ; Arinell et al, 2018 ), cycles of hypoxia-reoxygenation, and cooling-rewarming with signs of endothelial activation ( Carey et al, 2003 ; Talaei et al, 2012 ). Additionally, at entrance of the hibernation season, hibernators are generally grossly overweight ( Martin, 2008 ).…”

Reversible thrombocytopenia during hibernation originates from storage and release of platelets in liver sinusoids

“…All hibernators are immobile during the torpor phase and some species even remain immobile during arousal phases until springtime (Carey et al 2003;Cooper et al 2016b;Utz et al 2009). At face value, hibernators would suffer an increased risk of thrombosis because of the presence of several risk factors for thrombosis, including obesity in the pre-hibernation phase (Martin 2008), and immobility (Carey et al 2003), reduced blood flow (Bullard and Funkhouser 1962) and increased blood viscosity during torpor (Halikas and Bowers 1973;Kirkebo 1968). Hibernation is associated with crucial changes in the hemostatic system during torpor consistent with a reduced risk of thrombosis, amongst others by reducing platelet count with more than 90% and reducing coagulation factors, such as factor VIII and IX, suppressing blood clotting (Cooper et al 2012;de Vrij et al 2014;Lechler and Penick 1963).…”

Effects of Age and Season on Blood Parameters of Captive Giant Pandas: A Pilot Study

“…Therefore, the main reason for increased whole blood viscosity may be due to red blood cell aggregation. Studies have shown that ambient temperature (climate) has an effect on both blood viscosity and plasma viscosity in animals [18][19][20][21]. When the temperature decreases, blood flow slows down, blood viscosity increases, and red blood cell aggregation is enhanced [22][23][24].…”

Hibernation and hemostasis

“…As expected, blood pressure also drops from 140/100 mmHg to 60/30 mmHg, with values as low as 10 mmHg reported ( Lyman and O’brien 1960 ). Thus hibernation entails periods of prolonged immobility ( Carey et al, 2003 ; Utz et al, 2009 ) with low blood flow (stasis) in veins and atria ( Horwitz et al, 2013 ), increased blood viscosity ( Kirkebo, 1968 ; Halikas and Bowers, 1973 ; Arinell et al, 2018 ), cycles of hypoxia-reoxygenation, and cooling-rewarming with signs of endothelial activation ( Carey et al, 2003 ; Talaei et al, 2012 ). Additionally, at entrance of the hibernation season, hibernators are generally grossly overweight ( Martin, 2008 ).…”

Reversible thrombocytopenia during hibernation originates from storage and release of platelets in liver sinusoids

“…All hibernators are immobile during the torpor phase and some species even remain immobile during arousal phases until springtime (Carey et al 2003;Cooper et al 2016b;Utz et al 2009). At face value, hibernators would suffer an increased risk of thrombosis because of the presence of several risk factors for thrombosis, including obesity in the pre-hibernation phase (Martin 2008), and immobility (Carey et al 2003), reduced blood flow (Bullard and Funkhouser 1962) and increased blood viscosity during torpor (Halikas and Bowers 1973;Kirkebo 1968). Hibernation is associated with crucial changes in the hemostatic system during torpor consistent with a reduced risk of thrombosis, amongst others by reducing platelet count with more than 90% and reducing coagulation factors, such as factor VIII and IX, suppressing blood clotting (Cooper et al 2012;de Vrij et al 2014;Lechler and Penick 1963).…”

Effects of Age and Season on Blood Parameters of Captive Giant Pandas: A Pilot Study

“…Therefore, the main reason for increased whole blood viscosity may be due to red blood cell aggregation. Studies have shown that ambient temperature (climate) has an effect on both blood viscosity and plasma viscosity in animals [18][19][20][21]. When the temperature decreases, blood flow slows down, blood viscosity increases, and red blood cell aggregation is enhanced [22][23][24].…”

Hibernation and hemostasis

“…As expected, blood pressure also drops from 140/100 mmHg to 60/30 mmHg, with values as low as 10 mmHg reported ( Lyman and O’brien 1960 ). Thus hibernation entails periods of prolonged immobility ( Carey et al, 2003 ; Utz et al, 2009 ) with low blood flow (stasis) in veins and atria ( Horwitz et al, 2013 ), increased blood viscosity ( Kirkebo, 1968 ; Halikas and Bowers, 1973 ; Arinell et al, 2018 ), cycles of hypoxia-reoxygenation, and cooling-rewarming with signs of endothelial activation ( Carey et al, 2003 ; Talaei et al, 2012 ). Additionally, at entrance of the hibernation season, hibernators are generally grossly overweight ( Martin, 2008 ).…”

Reversible thrombocytopenia during hibernation originates from storage and release of platelets in liver sinusoids

“…All hibernators are immobile during the torpor phase and some species even remain immobile during arousal phases until springtime (Carey et al 2003;Cooper et al 2016b;Utz et al 2009). At face value, hibernators would suffer an increased risk of thrombosis because of the presence of several risk factors for thrombosis, including obesity in the pre-hibernation phase (Martin 2008), and immobility (Carey et al 2003), reduced blood flow (Bullard and Funkhouser 1962) and increased blood viscosity during torpor (Halikas and Bowers 1973;Kirkebo 1968). Hibernation is associated with crucial changes in the hemostatic system during torpor consistent with a reduced risk of thrombosis, amongst others by reducing platelet count with more than 90% and reducing coagulation factors, such as factor VIII and IX, suppressing blood clotting (Cooper et al 2012;de Vrij et al 2014;Lechler and Penick 1963).…”