TY - JOUR

T1 - Tail vein transection bleeding model in fully anesthetized hemophilia A mice

AU - Illa, Ariadna Carol

AU - Baumgarten, Sarah

AU - Danielsen, Dennis

AU - Larsen, Karin

AU - Elm, Torben

AU - Johansen, Peter B.

AU - Knudsen, Tom

AU - Lauritzen, Brian

AU - Tranholm, Mikael

AU - Ley, Carsten D.

N1 - Publisher Copyright: © 2021 JoVE Journal of Visualized Experiments.

PY - 2021

Y1 - 2021

N2 - Tail bleeding models are important tools in hemophilia research, specifically for the assessment of procoagulant effects. The tail vein transection (TVT) survival model has been preferred in many settings due to sensitivity to clinically relevant doses of FVIII, whereas other established models, such as the tail clip model, require higher levels of procoagulant compounds. To avoid using survival as an endpoint, we developed a TVT model establishing blood loss and bleeding time as endpoints and full anesthesia during the entire experiment. Briefly, anesthetized mice are positioned with the tail submerged in temperate saline (37°C) and dosed with the test compound in the right lateral tail vein. After 5 min, the left lateral tail vein is transected using a template guide, the tail is returned to the saline, and all bleeding episodes are monitored and recorded for 40 min while collecting the blood. If no bleeding occurs at 10 min, 20 min, or 30 min post-injury, the clot is challenged gently by wiping the cut twice with a wet gauze swab. After 40 min, blood loss is quantified by the amount of hemoglobin bled into the saline. This fast and relatively simple procedure results in consistent and reproducible bleeds. Compared to the TVT survival model, it uses a more humane procedure without compromising sensitivity to pharmacological intervention. Furthermore, it is possible to use both genders, reducing the total number of animals that need to be bred, in adherence with the principles of 3R's. A potential limitation in bleeding models is the stochastic nature of hemostasis, which can reduce the reproducibility of the model. To counter this, manual clot disruption ensures that the clot is challenged during monitoring, preventing primary (platelet) hemostasis from stopping bleeding. This addition to the catalog of bleeding injury models provides an option to characterize procoagulant effects in a standardized and humane manner.

AB - Tail bleeding models are important tools in hemophilia research, specifically for the assessment of procoagulant effects. The tail vein transection (TVT) survival model has been preferred in many settings due to sensitivity to clinically relevant doses of FVIII, whereas other established models, such as the tail clip model, require higher levels of procoagulant compounds. To avoid using survival as an endpoint, we developed a TVT model establishing blood loss and bleeding time as endpoints and full anesthesia during the entire experiment. Briefly, anesthetized mice are positioned with the tail submerged in temperate saline (37°C) and dosed with the test compound in the right lateral tail vein. After 5 min, the left lateral tail vein is transected using a template guide, the tail is returned to the saline, and all bleeding episodes are monitored and recorded for 40 min while collecting the blood. If no bleeding occurs at 10 min, 20 min, or 30 min post-injury, the clot is challenged gently by wiping the cut twice with a wet gauze swab. After 40 min, blood loss is quantified by the amount of hemoglobin bled into the saline. This fast and relatively simple procedure results in consistent and reproducible bleeds. Compared to the TVT survival model, it uses a more humane procedure without compromising sensitivity to pharmacological intervention. Furthermore, it is possible to use both genders, reducing the total number of animals that need to be bred, in adherence with the principles of 3R's. A potential limitation in bleeding models is the stochastic nature of hemostasis, which can reduce the reproducibility of the model. To counter this, manual clot disruption ensures that the clot is challenged during monitoring, preventing primary (platelet) hemostasis from stopping bleeding. This addition to the catalog of bleeding injury models provides an option to characterize procoagulant effects in a standardized and humane manner.

U2 - 10.3791/62952

DO - 10.3791/62952

M3 - Journal article

C2 - 34661578

AN - SCOPUS:85118598880

VL - 175

JO - Journal of Visualized Experiments

JF - Journal of Visualized Experiments

SN - 1940-087X

M1 - e62952

ER -