Influência do equilíbrio redox na resistência a fibrose pulmonar induzida por bleomicina em camundongos

Abstract

The development of bleomycin-induced pulmonary fibrosis (PF) has been associated with differences in genetic background and oxidative stress status. Our aim was to investigate the cross-talk between the redox profile, lung architecture and function in PF in different mouse strains. A single dose of either bleomycin (0.1 U/mouse) or saline (50 μL) was by intratracheal (i.t.) administration in C57BL/6, DBA/2 and BALB/c mice. Twenty-one days after bleomycin, the mortality rate was over 50% in C57BL/6 and 20% in DBA/2 mice and PF was not observed in BALB/c. There was an increase in Est (p<0.001), ΔP2 (p<0.05), ΔPtot (p<0.01) and ΔE (p<0.05) in C57BL/6 mice. Septa volume increase in C57BL/6 (p<0.05) and DBA/2 (p<0.001). The levels of INF-γ were reduced by in C57BL/6 mice (p <0.01). OH-proline levels were increased in C57BL/6 and DBA/2 mice (p<0.05). SOD activity and expression was reduced in C57BL/6 and DBA/2 mice (p<0.001 and p<0.001 respectively), whereas CAT was reduced in all strains 21 days following bleomycin when compared to saline groups (C57BL/6: p<0.05; DBA/2: p<0.01, BALB/c: p<0.01). GPx activity and GPx1/2 expression decreased in C57BL/6 (p<0.001). We conclude that the PF resistance may also be related to the activity and expression of SOD in BALB/c