Fig. 1.

Dependence of NADPH oxidase activity as a function of cholesterol concentration in the absence of arachidonic acid. Membrane fractions (2 nM Cyt b₅₅₈) with trimera 200 nM were incubated 4 min in presence of different concentrations of cholesterol. Control experiment representing 100% (68 mol O₂^•−/s/mol Cyt b₅₅₈) of the activity was realized in presence of 40 µM AA and in absence of cholesterol. The rates of superoxide production were measured as described in Materials and methods. The data are the average of 3 independent measurements±SEM.