The effect of inhaled budesonide on the expression of hydroxyproline and type I and III collagen mRNA in lung tissue of bleomycin-induced rat pulmonary fibrosis.

Objective To investigate the effect of inhaled budesonide on the expression of hydroxyproline and type Ⅰ/Ⅲ collagen mRNA in lung tissue of bleomycin-induced rat pulmonary fibrosis.Methods Forty-five adult female Wistar rats were randomly divided into 3 groups:both budesonide(Bud) group and bleomycin(BLM) group were intratracheally instilled with BLM,and normal solution(NS) group with 0.9% NaCl solution.Both NS group and BLM group were aerosolized with NS,while Bud group with budesonide every day at day 0～6 after rats were intratracheally administrated.Each group was again divided into 3 subgroups,which were sacrificed at day 7,14 and 28.Hydroxyproline content was detected;HE and Masson staining were performed to observe the extent of alveolitis and fibrosis;The mRNA levels of type Ⅰ/Ⅲ collagen in the lung tissue were measured by RT-PCR.Results The extent of alveolitis in Bud group at day 7 and 14 were lower than those of BLM group(P0.05).The extent of lung fibrosis and the expressions of hydroxyproline in Bud group at day 7,14 and 28 were significantly lower than those of BLM group(P0.05);The mRNA levels of type Ⅰ/Ⅲ collagen at day 7 and 14 in Bud group were significantly lower than those in BLM group(P0.05).Conclusion Inhaled budesonide could decrease the levels of hydroxyproline and type Ⅰ/Ⅲ collagen mRNA and ameliorate the formation of pulmonary fibrosis in bleomycin-induced rat pulmonary fibrosis.