The respiratory burst of neutrophils is an important response in inflammation. The alterations in extracellular pH per se is not a sufficient trigger to the respiratory burst in neutrophils. While neutrophils in respose to conventional agonists, the respiratory burst in neutrophils is affected by the alterations in extracellular pH, and there is a direct relationship between intracellular and extracellular pH. O-· 2 production in neutrophils is decreased while H 2O 2 production is increased at acidic pH. O-· 2 release in neutrophils is enhanced at weak alkaline pH. Na+/H+ exchanger plays an important role in the regulation of the respiratory burst of neutrophils.