Assessment of vascular function and contractility, Ex Vivo

Abstract

In this chapter, I will describe two useful techniques utilised in the laboratory to assess vascular function and contractility. An important function of the vasculature is the regulation of blood pressure to ensure that blood perfusion into tissues is matched to demand. One essential factor controlling arterial blood pressure is peripheral resistance. The walls of blood vessels include a medial layer of smooth muscle cells, which through contraction and relaxation, are able to control vessel diameter, hence peripheral resistance. The inner endothelial layer, on the other hand, is an important modulator of these responses, through the release of vasoconstrictor and vasodilator substances, in response to both mechanical and pharmacological stimuli. It is possible to examine aspects of vessel function and to explore the role of endothelial derived mediators in modulating this function, by using an ex vivo system that enables the maintenance of isolated vessels in a viable state. A number of these exist. Here, I shall introduce you to the ‘Organ bath’ system, utilised for conduit and large size vessel studies, followed by ‘Pressure myography’, a state-of-the-art system that more closely mimics the physiological state, by enabling the maintenance of viable small size vessels (40–450 μm diameter) under pressure, flow, and temperature.