Methods for studying microvascular barrier function in ischemia-reperfusion injury

Ischemia-reperfusion (I/R) injury is accompanied by functional disturbances in the microcirculation that often translate into significant morbidity and mortality. We present an overview of methods to evaluate microvascular barrier properties and how these methods can be applied to the study of I/R injury. Included is a summary of techniques for measuring 1) fluid and macromolecule flux from the vascular compartment into the interstitial space of tissues and 2) the permeability parameters of microvascular wall. Several experimental models will be surveyed including whole animal, isolated organ, individually perfused microvessels and cultured endothelial cells using examples from our own studies and work of other investigators relating to I/R-induced endothelial injury. The strengths and weaknesses of these different approaches are discussed.