Renin-angiotensin system and its role in hyperoxic acute lung injury

Oxygen is essential to sustain life, but at a high partial pressure oxygen may cause toxicity to the human body. These injuries to the lung are known as hyperoxic acute lung injury [HALI]). To date, numerous studies have been conducted to investigate the pathogenesis of HALI, for which some hypotheses have been proposed. Accumulating evidence indicates that the renin-angiotensin system (RAS) plays an important role in the pathogenesis of some lung diseases, including acute lung injury (ALI), chronic obstructive pulmonary disease (COPD) and HALI. In this review, we briefly introduce the classic RAS, local (tissue) RAS and intracellular RAS, and we summarize findings on the relationship between local/classic RAS and HALI. The importance--and ambiguity--of the results of these studies indicate a need for further investigations of the RAS and its role in the patho- genesis of HALI.