Nitric Oxide Synthase Enzymes in the Airways of Mice Exposed to Ovalbumin: NOS2 Expression Is NOS3 Dependent

Figure 1

Total cells recovered by lung lavage from strains of mice exposed to filtered air (a), or 2 weeks of OVA aerosol, (b) and total eosinophils from mice exposed to 2 weeks of OVA aerosol (c). Of the filtered air-exposed mice (a), the NOS2${}^{-/-}$ mice had a greater number of cells present in their lavage ($8.65\pm 6.90\times {10}^4$ ($n=16$), $P<.01$) compared to the other genotypes of mice examined (NOS1${}^{-/-}\mathrm{\hspace{0.17em}\hspace{0.17em}}$$2.78\pm 1.71\times {10}^4$ ($n=12$), NOS3${}^{-/-}$$3.03\pm 1.68\times {10}^4$ ($n=11$), C57Bl/6 $3.85\pm 2.98\times {10}^4$ ($n=27$)). Of the OVA-exposed mice, the NOS2${}^{-/-}$ mice had $15.65\pm 9.93\times {10}^5$ ($P<.05\text{,}$$n=17$) cells (b), significantly more than either NOS1 ($6.20\pm 5.05\times {10}^5$ ($n=12$)), NOS3 ($6.7\pm 1.4\times {10}^5$ ($n=11$)), or C57BL/6 ($7.86\pm 8.02\times {10}^5$ ($n=21$)) mice. Eosinophils comprised a significant proportion of the cells present in the lavage of mice exposed to OVA. NOS2${}^{-/-}$ mice exposed to OVA had $11.9\pm 1.76\times {10}^5$ eosinophils (c) in lavage, which was significantly more than in NOS1 ($2.4\pm 0.6\times {10}^5$), NOS3 ($5.3\pm 0.45\times {10}^5$), or C57BL/6 ($2.9\pm 3.0\times {10}^5$) mice exposed to OVA. Data are presented as mean values ± SEM. ${}^{*}$ denotes $P<.05\text{;}$${}^{**}P<.01$ by ANOVA.

(a)

(b)

(c)