Vasoreactivity of the Mouse Aorta : Vessel Characterization through in-vitro Tube Inflation

Sammanfattning

Cardiovascular diseases remain a leading cause of mortality worldwide, and altered vascular mechanics play a central role in their development and progression. Arterial behavior results from the interaction between passive extracellular matrix components and active contraction of Vascular Smooth Muscle Cells (VSMCs). However, experimental investigations that clearly separate passive and active mechanical responses remain limited. The goal of this study is to redesign and implement an in-vitro experimental setup capable of assessing vasoreactivity of the mouse aorta under controlled biochemical and biomechanical conditions using a volume-controlled inflation protocol. The system integrates pressure measurement, synchronized video acquisition, image-based diameter tracking, and pharmacological modulation of vascular tone. Pressure-diameter and tension-stretch relationships were obtained for passive, normal tone, and maximally activated states. Smooth muscle activation induced a clear downward shift of the pressure-diameter relationship, resulting in a diameter reduction of approximately 17% within the physiological pressure range (10.7 to 16 kPa). The tension-stretch analysis showed a leftward shift under activated conditions, indicating additional active circumferential tension generated by VSMCs. Overall, the implemented setup successfully discriminates between passive and active vessel behavior and reproduces physiologically relevant vascular responses. These findings demonstrate the suitability of the system for further investigations of active arterial mechanics and constitutive modeling of vascular tissues.