Comparison of Methods used to Measure NADH-Dependent GSNO-R Activity.

Lungs were harvested from adult (10–12 w) C57Bl6/129SeEv mice. Lung homogenates were subjected to NADH-dependent GSNO-R activity. The assay was performed as described in Methods. The effect of altering the concentration of GSNO in the assay and the precipitation of protein prior to measurement were compared in the same samples (n = 4). Note that higher activity was obtained in the absence of protein precipitation for both GSNO concentrations. Highest GSNO-R activity was obtained in the presence of 100 µM GSNO. GSNO-R activity was found to be 2–3 fold higher in the lung homogenates from female animals regardless of the method used to measure activity.