TABLE 2.

Dose responses for murine neutrophils following N₂ exposures

Data show MPs production as particles/neutrophil/hour by cells first exposed to air + various additional pressure of N₂ for 30 minutes. iNOS indicates pmol of [³H] citrulline produced in 1 hour after cells were exposed to N₂ pressure. NOX indicates rate of O₂ consumption as μmol O₂ × 10–3/min/1 × 106 neutrophils studied after 30 minute exposures to N₂. Values were taken from the linear portion of consumption assays as shown in Figure 4.

Air + kPa N2	MPs/PMN/hr	iNOS	NOX
0	0.0003 ± 0.0002 (24)	0.19 ± 0.02 (21)	1.37 ± 0.14 (11)
186	0.08 ± 0.02 (4)*	0.47 ± 0.12 (3)*	1.95 ± 0.12 (4)*
228	0.72 ± 0.10 (4)*	0.73 ± 0.13 (7)*	2.42 ± 0.23 (4)*
345	1.14 ± 0.08 (8)*	0.83 ± 0.22 (6)*	3.57 ± 0.14 (4)*
455	2.08 ± 0.41 (4)*	1.45 ± 0.15 (3)*	4.09 ± 0.28 (4)*
690	3.84 ± 0.21 (8)*†	1.76 ± 0.08 (24)*†	5.00 ± 0.36 (10)*†

*p < 0.05 versus 0 kPa N₂ (air-exposed, control) in each column.

^†Significantly different from 186 and 228 kPa values by ANOVA.