BAL FLUID CONTAINS DETECTABLE SUPEROXIDE-DISMUTASE-1 ACTIVITY

Objective: This study determined which, if any, of the three superoxid e dismutase (SOD) enzyme activities were detectable in BAL fluid (BALF ). Background: The identity and concentrations of antioxidant molecule s in BALF have not been fully characterized. One important class of an tioxidants is that of the SOD enzymes. Methods: BALF from control nons mokers (n=9), smokers (n=7), and asthmatic subjects (n=12) were examin ed for SOD activity by a modified pyrogallol auto-oxidation method. Th e particular SOD enzyme or enzymes responsible for any activity were i dentified based on activity inhibition data and gel filtration column chromatography patterns. Results: SOD activity was detected in all sam ples. Unlike serum or some other fluids, in which the enzyme extracell ular SOD accounts for virtually all SOD activity, the enzyme SOD 1 acc ounted for virtually all SOD activity. BALF SOD activities were lower for smokers than for control or asthmatic subjects (p<0.05). Conclusio n: BALF SOD 1 activities can be measured as part of lung antioxidant s tudies. Data from a limited number of subjects suggested that smokers can have low BALF SOD values.