Adenosine is a purine nucleoside base which is the precursor of adenosine triphosphate or ATP and is utilized thoroughly throughout the entire body in general metabolism. Extracellular adenosine acts as a local modulator with a generally cytoprotective function in the body. Its effects on tissue protection and repair fall into four categories increasing the ratio of oxygen supply to demand protecting against ischaemic damage by cell conditioning triggering anti-inflammatory responses and the promotion of angiogenesis.