EFFECTS OF OXYGEN-TENSION AND PH ON THE RESPIRATORY BURST OF HUMAN-NEUTROPHILS

  • 1 January 1979
    • journal article
    • research article
    • Vol. 53  (6) , 1133-1139
Abstract
The respiratory burst of human neutrophils was measured under conditions of hypoxia and low pH. O2- production by neutrophils activated with opsonized zymosan fell slowly as the O2 concentration declined to 1%, then dropped more sharply, reaching negligible levels at O2 concentrations less than 0.25%. Production was half maximal at an O2 concentration of 0.35% (equivalent to .apprx. 10-.mu.M dissolved O2). O2- production by the cell-free O2--forming system prepared from zymosan-activated neutrophils showed a similar dependence on O2 concentration. A drop in pH caused decreases in O2 consumption and O2- production by zymosan-treated neutrophils, values at pH 6.0 being 10%-20% of those obseved at pH 7.5. Experiments with the cell-free O2--forming system suggested that this decline in respiratory burst activity at low pH was due to inefficient activation of the O2--forming enzyme under acidic conditions.