Effects Of Valsartan On The Rat Model Of Pulmonary Fibrosis And The Expression Of HGF In Lung Tissue

Background and Objective Recent studies implicate ACE in fibrosis by transforming growth factor- β (TGF-β₁).Ferther study confirmed that ACEI and antagonist of ANG receptor AT1 can reduced the expressing of some cytokine deduced by Ang â… , so they can impact on organic fibrosis.At present, AT1 antagonist has been used to treat cardiovascular diseases and diabetic nephropathy, the effect on pulmonary fibrosis isn't been well understood, and we still need the experiment and clinic research on this subject.We investigate the expression and significence of hepatocyte growth factor (HGF) and TGF-β₁ in bleomycin-induced pulmonary fibrosis in rats, to study the effect of valsartan (VAL) and its possible mechanism.Materials and Methods Sixty Wastar rats were divided into three groups in random: control group, untreat model - I group, valsartan- treated- I group. On experimental day (day 0), the rats were intratracheally instilled with bleomycin (5mg/kg body weigh) or sterile saline, and then treated with VAL(16mg-1.kg-1.d-1 , intraperitoneally) or streile saline until they were killed. Five rats in each group were sacrificed 7, 14, 28, and 42 days after intratrachel instillation.Lung moduli were measured , the blood was collected for determination of HGF protein level by ELISA.The left lung tissues were observed by Hestain, Masson's trichrome stain to evaluated histological changes, the expression of TGF-β₁ protein and HGFmRNA in lung was assessed by immunohistochemical technique and in situ hybridization.The right lung tissue was used to test the concentration of hydroxyproline and HGFprotein.Another ten rats to have been instilled BLM were divided into two groups in random 14 days latter:untreated model- â…¡ group and VAL-treated- â…¡ group.On day 28 after treatment of VAL or sterile saline, their lungs were drawed for Hestain , Masson's trichrome stain, and protein expression of TGF- β₁ and HGF.Results The level of HGF in serum was elevated quikly after BLM instillation andpeaked on day 7(P<0.0\), then declined, but still it was higher than that of the control(P