Effect of ageing on the murine venous circulation

Area of Science:

• Vascular biology
• Gerontology
• Hematology

Background:

• Aging affects vascular structures, including arteries and veins.
• Venous valves play a critical role in blood circulation and preventing backflow.
• Age-related changes in the vasculature can impact blood coagulation and inflammation.

Purpose of the Study:

• To investigate the effects of aging on the morphology of veins, venous valves, and arteries in mice.
• To analyze age-related changes in vascular structure and blood coagulation profiles.
• To understand the relationship between vascular changes and a procoagulant/inflammatory state in aging.

Main Methods:

• Utilized Microfil(®) injection to preserve vasculature morphology in young (10-week-old) and aged (24-month-old) male C57BL/6 mice.
• Performed morphological analysis of arterial and venous lumen area, wall thickness, and venous valve structure.
• Assessed endothelial protein expression (CD31, thrombomodulin, von Willebrand factor) and evaluated blood coagulation parameters (prothrombin time, coagulation factors, cell counts).

Main Results:

• Aged mice exhibited significantly greater arterial lumen area and wall thickness compared to young mice.
• Venous valves in aged mice showed reduced structural support from collagen fibers, indicating increased fragility.
• Aged mice displayed a procoagulant phenotype, characterized by shortened prothrombin time, elevated coagulation factors (FVII, FVIII, VWF), and increased neutrophil and platelet counts.

Conclusions:

• Aging in mice is associated with increased fragility of venous valves and mild vascular changes.
• A procoagulant and inflammatory blood phenotype accompanies aging, linked to vascular alterations.
• These findings highlight age-related vulnerabilities in the vascular and coagulation systems.