Gasotransmitters

Gasotransmitters are a class of small endogenously produced gaseous signaling molecules. They are dissolved gases in blood and other body fluids, and play important roles in cellular homeostasis and impact physiological and pathophysiological conditions. Nitric oxide was the first gasotransmitter to be identified followed by carbon monoxide, while hydrogen sulfide was recently established as the third member of the gasotransmitter family. Although these gases gained historic notoriety for their toxicity and death, studies over the past few decades have shown that they have risen above their notorious tags and have now emerged as important intracellular mediators of cytoprotection in various pathological conditions such as ischemia-reperfusion injury in organ transplantation. This chapter introduces gasotransmitters as volatile intracellular messenger molecules, with complex interactions with one another in compensatory and reciprocal fashion when the level of one is depleted under pathological conditions. In addition, the chapter also summarizes various therapeutic properties of these gases such as antioxidant, anti-inflammatory, anti-apoptotic and vasodilatory properties, enabling them to mediate donor organ protection during pre-transplant, peri-operative and post-transplant periods, and ultimately contributing to improving organ graft quality and prolonging transplant recipient survival.