Table 5.

Lung PMNs from LPS-treated WT and MMP-8^−/− mice have similar levels of intracellular active caspase-3.

Condition	Intracellular active caspase-3 (pg)
WT BAL PMN, IT LPSC	444.7 (50.7)E
MMP-8−/− BAL PMN, IT LPS	407.7 (58.6)
Human PMN, T= 0 hD	N.D.F
Human PMN, T=18 h	17,095 (1690)

^CPMNs were isolated from the lungs of WT and MMP-8^−/− mice, both in the C57BL/6 strain, by BAL 24 h after IT instillation of LPS (n=7 mice/group). Extracts of BAL PMNs were prepared at 5 × 10⁶/ml and assayed for levels of active caspase-3 using a fluorogenic substrate specific for caspase-3 and assay standards of purified active caspase-3.

^DAs controls, human PMNs were induced to undergo apoptosis by culturing them in serum-free medium for 18 h at 37°C (Human PMNs T= 18 h), and active caspase 3 levels were quantified in extracts of these PMNs versus extracts of freshly isolated human PMN (Human PMN, T= 0 h) prepared at 5 × 10⁶/ml.

^EData are mean ± SD.

^FN.D. = not detected.