College
Buchtel College of Arts and Sciences
Date of Last Revision
2025-06-04 12:48:33
Major
Biomedical Science
Honors Course
BIOL 499
Number of Credits
4
Degree Name
Bachelor of Science
Date of Expected Graduation
Spring 2025
Abstract
Factor XI (FXI) deficiency, also known as Hemophilia C, is characterized by mild to moderate bleeding symptoms. However, the factors that modify bleeding severity in FXI deficiency are not fully understood. In this study, we investigated whether components of the contact activation pathway can act as modifiers of bleeding in the context of FXI deficiency. Using a tail vein transection (TVT) model in rats, we assessed bleeding in four experimental groups: wild-type Sprague-Dawley rats, Prekallikrein knockout (PKK-/-) rats, rats treated with a FXI-inhibiting antibody, and PKK-/- rats treated with the FXI antibody.
Under anesthesia, each rat underwent a standardized incision on the lateral tail vein. The procedure lasted 30 minutes and consisted of three 10-minute intervals, initiated either by the incision or by mechanical agitation (wiping) of the wound. Bleeding time was recorded during each interval, and total blood loss was collected. Following red blood cell lysis, hemoglobin concentration was measured spectrophotometrically to quantify blood loss. Hemoglobin levels were also confirmed via terminal inferior vena cava (IVC) collection and analysis using a Hemavet.
Results showed that total bleeding time was modestly prolonged in PKK-/- rats, FXI-inhibited rats, and in those with both PKK-/- and FXI inhibition. Notably, the combination of PKK-/- and FXI inhibition led to a significant increase in hemoglobin loss compared to controls. These findings suggest that Prekallikrein may serve as an alternative activator of downstream coagulation factor IX, thereby modifying hemostatic function in the absence of FXI of coagulation function.
Research Sponsor
Brian Bagatto
First Reader
Joseph Palumbo
Second Reader
Rachel Olson
Honors Faculty Advisor
Brian Bagatto
Proprietary and/or Confidential Information
No
Recommended Citation
Han, Ivy R.; Rosenfeldt, Leah; Young, Courtney; Krishan, Bal PhD; Cantrell, Rachel PhD; Sprague, Cassie; Kharnaf, Mousa; Abplanalp, William; and Palumbo, Joseph MD, "Contact Pathway Factors as Potential Modifiers of Bleeding Related to Factor XI Deficiency" (2025). Williams Honors College, Honors Research Projects. 2050.
https://ideaexchange.uakron.edu/honors_research_projects/2050
Included in
Animals Commons, Hematology Commons, Laboratory Medicine Commons, Physiological Processes Commons, Surgery Commons