Contribution of secretory leukocyte proteinase inhibitor to the antiprotease defense system of the peripheral lung: effect of ozone-induced acute inflammation.
Secretory leukocyte protease inhibitor (SLPI) and elafin are structurally similar, low-molecular-weight antiproteases produced in the lung. We have developed a simple method for distinguishing the antiprotease activities of SLPI and elafin in lung lavage fluid from those of alpha 1-antitrypsin (alpha 1-AT) that is based on the resistance of the low-molecular-weight antiproteases to inactivation by cetyltrimethylammonium bromide. In a study of 23 healthy, nonsmoking volunteers, we found that the low-molecular-weight antiproteases accounted for 22 +/- 2% (mean +/- SEM, n = 23) of the total neutrophil elastase-inhibitory capacity of human bronchoalveolar lavage fluid (BALF). Elafin activity was below the limit of detection. SLPI activity (as measured by inhibition of alpha-chymotrypsin) accounted for 72 +/- 4% (mean +/- SEM, n = 23) of the low-molecular-weight antiprotease activity in BALF. Measurements of SLPI in the lavage fluid samples by enzyme-linked immunosorbent assay (ELISA) agreed closely with values obtained by measuring the activity of this inhibitor. The activity of the low-molecular-weight antiproteases decreased significantly (p < 0.05), from 9.0 +/- 0.8 to 7.0 +/- 0.6 pmol of neutrophil elastase inhibited per mL (mean +/- SEM, n = 23), following acute ozone exposure.
Nadziejko
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C
Institute of Environmental Medicine, New York University Medical Center, Tuxedo 10987, USA.
Finkelstein
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I
Balmes
J R
JR
D000208:Acute Disease; D000328:Adult; D001992:Bronchoalveolar Lavage Fluid / Q000737:chemistry; D001999:Bronchoscopy; D018592:Cross-Over Studies; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D008168:Lung / Q000187:drug effects / Q000201:enzymology*; D008297:Male; D008970:Molecular Weight; D010126:Ozone / Q000009:adverse effects*; D011014:Pneumonia / Q000139:chemically induced / Q000201:enzymology*; D053491:Proteinase Inhibitory Proteins, Secretory; D011506:Proteins / Q000032:analysis / Q000502:physiology*; D053481:Secretory Leukocyte Peptidase Inhibitor; D015842:Serine Proteinase Inhibitors / Q000032:analysis / Q000502:physiology*; D016037:Single-Blind Method
D053491:Proteinase Inhibitory Proteins, Secretory; D011506:Proteins; C506814:SLPI protein, human; D053481:Secretory Leukocyte Peptidase Inhibitor; D015842:Serine Proteinase Inhibitors; D010126:Ozone