右归饮对肺纤维化大鼠的疗效评价及作用机制

目的:探讨温补肾阳的代表方剂右归饮对博莱霉素致肺纤维化大鼠的药效作用和相关机制。方法:SPF级雄性SD大鼠25只,采用随机数字法,将SD大鼠分为正常组、模型组、右归饮高、中、低剂量组,每组各5只。气管内注射博莱霉素(5 mg·kg-1)建立实验性肺纤维化模型,并于造模后第15天开始灌胃高、中、低剂量(20,10,5 g·kg-1)右归饮,连续给14 d。用动物肺功能仪检测大鼠吸气阻力(Ri),呼气阻力(Re),肺顺应性(Cdyn),用力肺活量(FVC),0.4 s率(FEV0.4/FVC%),呼气峰值流速(PEF),最大呼气中期流速(MMF),计算质量FVC;称量脏器质量和大鼠体质量,计算脏器系数;用血气分析仪检测腹主动脉酸碱度(p H),氧分压(PO_2),二氧化碳分压(PCO_2),氧饱和度(SO_2);用酶联免疫吸附法(ELISA)检测血清中肾素,前列腺素E2(PGE2),基质金属蛋白酶-1(MMP-1)含量;取左肺进行马松(Masson)染色观察肺组织的病理变化。结果:与正常组比较,气管内注射5 mg·kg-1博莱霉素能够明显增加SD大鼠肺脏质量和肺脏系数(P0.05),降低Cydn,FVC和质量FVC(P0.05),增加Ri(P0.05),升高FEV0.4/FVC%(P0.05),升高腹主动脉血中PCO_2水平(P0.05),明显降低PO_2,SO_2水平(P0.05),升高血清中PGE2水平(P0.05),病理显示模型大鼠肺组织形成大量实变区,发生实变的肺组织以细胞异常增殖为主的非纤维化区和伴有大量细胞外基质沉积的纤维化区为主。与模型组相比,右归饮中剂量组肺脏质量明显回落(P0.05),Cydn,FVC和质量FVC回升(P0.05),Ri,FEV0.4/FVC%下降(P0.05),血清中PGE2水平下降(P0.05);右归饮高剂量组能够明显升高动脉血中PO_2,SO_2水平(P0.05)。病理显示右归饮中剂量组能够抑制肺组织实变区向非实变区的炎性浸润。结论:右归饮能够改善实验性肺纤维化SD大鼠的肺功能,与右归饮降低血清中PGE2水平,抑制炎性浸润区的扩散,延缓纤维化进程有关。

Efficacy Evaluation and Mechanisms of Youguiyin in Rats with Pulmonary Fibrosis

Objective: To investigate the efficacy and mechanism of Youguiyin, a representative decoction of tonifying kidney yang, in the rats with bleomycin induced pulmonary fibrosis. Method: A total of 25 SPF male rats were divided into five groups by the method of random number table, namely normal group, model group, as well as Youguiyin high, medium and low dose groups, with 5 rats in each group. Pulmonary fibrosis models were established by intratracheal injections of bleomycin(5 mg·kg^-1), and the rats were treated with high, medium and low doses (20, 10, 5 g·kg^-1) of Youguiyin for 14 days from day 15 after modeling. Then the inspiratory resistance (Ri), expiratory resistance (Re), lung compliance (Cdyn), forced vital capacity (FVC), 0.4 second rate (FEV_0.4/FVC%), peak expiratory flow rate (PEF), and maximum mid expiratory flow velocity (MMF) were tested by animal lung function instrument, and FVC/lung weight were calculated; the weights of organs were recorded and the organ coefficient was calculated. The pH values of abdominal aorta (pH), oxygen partial pressure (PO₂), carbon dioxide pressure (PCO₂), oxygen saturation (SO₂) were detected by blood gas analyzer. Renin, prostaglandin E₂ (PGE₂) and matrix metalloproteinase-1 (MMP-1) levels in serum were measured with enzyme linked immunosorbent assay (ELISA). Histopathological abnormalities in left lungs were evaluated by Masson''s trichrome stain. Result: As compared with the normal group, intratracheal injection of 5 mg·kg^-1 bleomycin can significantly increase the lung weight and lung coefficient (P< 0.05), decrease Cdyn, FVC and FVC/lung weight (P< 0.05), increase Ri (P< 0.05), increase FEV_0.4/FVC% (P< 0.05), increase PCO₂ in abdominal aortic blood (P< 0.05), decrease PO₂ and SO₂ significantly (P< 0.05), and increase PGE₂ levels in serum (P< 0.05) of SD rats. Pathological examination of lung tissues showed large area of consolidation in lung tissue of model rats, and those lung tissues with consolidation were mostly formed by the non-fibrosis area with abnormal cell proliferation and fibrosis area with a large number of extracellular matrix deposition. As compared with the model group, Youguiyin medium dose group decreased the lung weight significantly (P<0.05), increased Cydn, FVC and FVC/lung (P<0.05), decreased Ri and FEV_0.4/FVC% (P<0.05), decreased PGE₂ levels (P< 0.05); while PO₂ and SO₂ levels in arterial blood were significantly increased in high dose group (P<0.05). Pathological examination showed Youguiyin can inhibit chronic inflammatory infiltration from pulmonary consolidation to normally aerated lung parenchyma. Conclusion: Youguiyin could improve the pulmonary function of model rats, which may be associated with lowing PGE₂ in serum, inhibiting the diffusion of chronic inflammatory infiltration, and delaying pulmonary fibrosis.