Objectives: Studies in rats have shown that the blood pressure dependent characteristics of arterial stiffness, as measured by pulse wave velocity (PWV), are useful in elucidating arterial properties contributing to hypertension in different disease models. Transgenic mouse models are increasingly being used to investigate underlying pathophysiological mechanisms of arterial stiffness. We have developed techniques in the rat that have been successful in characterising pressure-dependent PWV in the murine aorta in vivo. Methods: Beat-to-beat aortic PWV was measured in isoflurane anesthetized adult mice (n=5) using two high fidelity pressure sensors; one placed in the aortic arch via the left carotid artery, and the second underneath the abdominal aorta, to record extravascular tonometric pressure . PWV was characterised across a range of physiological blood pressures by intravenous bolus injections of phenylephrine (3.0μg) and sodium nitroprusside (3.0μg), to increase and decrease blood pressure respectively. Results: PWV (m/s) increased with MAP (mmHg) across the MAP range of 40-125mmHg according to a relationship described by a second order polynomial: PWV = 0.0006.MAP2- 0.0564.MAP+3.9711 (R2 = 0.98). This indicates that the sensitivity of PWV to changes in MAP increases linearly with pressure. Conclusion: This study provides, for the first time, the pressure-dependent relationship of PWV in the murine aorta. It also lays the groundwork for future experiments in knockout mice which will enables investigations of both altered vascular responses in hypertension and pressure dependent and independent mechanisms of arterial stiffness. References:  Wang YX, Halks-Miller M, Vergona R, Sullivan ME, Fitch R, Mallari C, et al. Increased aortic stiffness assessed by pulse wave velocity in apolipoprotein E-deficient mice. American Journal of Physiology - Heart and Circulatory Physiology. 2000;278(2 47- 2):H428-H34.
|Number of pages||1|
|Journal||Journal of Hypertension|
|Issue number||e-Supplement 1|
|Publication status||Published - 2012|
|Event||24th Meeting of the International Society of Hypertension - Sydney, Australia|
Duration: 30 Sep 2012 → 4 Oct 2012