Changes in Vascular Viscoelasticity Caused by Smooth Muscle Cell Tone and Pressurization Frequency

The cushioning and conduit functions of large arteries allow the body to efficiently circulate blood and perfuse organs. These functions can be characterized by quantifying the viscoelastic properties of arteries. In this study, we investigated the effects of smooth muscle cell (SMC) tone and pressurization frequency on vascular viscoelasticity using an isolated, perfused vessel test. We tested mouse carotid arteries in control, dilated (via sodium nitroprusside) and constricted (via the thromboxane receptor analogue U46619) states at 0.1, 1, 3, and 5 Hz with a pulse pressure from 90 to 120 mmHg. Dose response experiments were first performed in order to determine the optimal vasoconstrictor concentration to be used in frequency response experiments. Our results showed that energy dissipation was significantly higher and elasticity was significantly lower for vasoconstricted arteries. We also found that frequency significantly changed both energy dissipation and elasticity as the frequency was increased from 0.1 to 5 Hz. These results provide insights into the changes in vascular viscoelasticity caused by SMC tone and pressurization frequency, which have implications for vascular function in vivo.