Dr. John J. Lemasters is a pioneer of techniques that allow scientists to see what happens inside an individual cell during reoxygenation—the restoration of oxygen to an organ following oxygen deprivation, which sometimes occurs following a heart attack or stroke. The process of redistributing oxygen to an organ can be stressful on tissue, leading to possible trauma and even cell death.
Dr. Lemasters specializes in a kind of microscopy that allows scientists to view slices of an individual cell, much like CAT or MRI scans complement the more traditional X-ray by allowing doctors to view the body in layers.
His research interests concern the cellular and molecular mechanisms underlying hypoxic and toxic injury to liver and heart cells and organs stored for transplantation surgery. In particular, his laboratory is applying new techniques of laser scanning confocal and multiphoton microscopy to characterize the physiology of single living cells, including the assessment of ion homeostasis, mitochondrial function, electrical potentials, oxygen and nitrogen free radical formation, membrane permeability, and other biochemical parameters during the pathogenesis of lethal cell injury.