Table 2.

Effect of HNE and inhibitors administered intratracheally on induction of hemorrhage at 2 h and airspace enlargement at 4 wk

Treatment	Red blood cell pellet, g	Mean linear intercept, μm
PBS	0 (3)	44.40 ± 6.50 (4)
HNE/PBS	0.053 ± 0.028 (4)	51.45 ± 5.78 (10)
X0/PBS	—	43.27 ± 3.82 (4)
X0/HNE	0.035 ± 0.006 (4)	53.27 ± 8.27 (8)
SP-B1-25-X2/PBS	—	40.94 ± 1.59 (8)
SP-B1-25-X2/HNE	0.007 ± 0.007 (3)	45.82 ± 3.30 (8)

Values are the mean ± SD (number of animals in parentheses). The red blood cell pellet was obtained by saline bronchoalveolar lavage of the lungs 2 h after treatment followed by centrifugation. The HNE/PBS and X0/HNE groups had larger red blood cell pellets than the PBS control, but the SP-B1-25-X2/HNE group did not. The mean linear intercept (MLI), a measure of mean alveolar size, was determined as described and increased as alveolar walls were destroyed. There were no significant differences by ANOVA among the three non-HNE controls (PBS, X0/PBS, SP-B1-25-X2/PBS), and the MLI values were combined. The combined control MLI data were compared with values of the three HNE groups. The MLI values of the HNE/PBS and X0/HNE groups were significantly different from the combined control data, but the data of the SP-B1-25-X2/HNE group were not different. Thus the inhibitor linked to the peptide prevents emphysema, but the free inhibitor does not.