曲尼司特减轻松木屑烟雾吸入性损伤大鼠肺组织胶原沉积的研究

Effect of tranilast on collagen deposition in lung tissue of rats with sawdust smoke pine inhalation injury

目的观察曲尼司特对松木屑烟雾致大鼠肺组织损伤后胶原蛋白合成的影响,为曲尼司特防治松木屑烟雾吸入性损伤致肺组织胶原沉积乃至纤维化提供可行性。方法将72只雄性SD大鼠按照随机数字表法分为正常组、对照组、治疗组、盐水组,每组18只。对照组、治疗组和盐水组大鼠吸入松木屑烟雾共15 min(每间隔5 min吸烟1次,每次5 min,共吸烟雾3次),对照组不给予任何治疗,治疗组和盐水组于吸入烟雾后6 h,分别每天经腹腔注射1次曲尼司特(200 mg·kg^(-1))和0.9%氯化钠溶液0.5 mL,正常组大鼠不予致伤、治疗。伤后7、14、28 d,各组取肺组织行苏木精-伊红、Masson染色,并行组织病理评分和计算胶原沉积率(CVF),碱水解法测定肺组织中羟脯氨酸(HYP)含量,对数据行单因素方差分析、t检验。结果(1)苏木精-伊红染色:松木屑烟致伤后7 d,对照组和盐水组大鼠肺组织中均可见不同程度炎性细胞浸润、充血、肺间质水肿,随着观察时间的延长,肺组织炎性细胞浸润增加、出血增多,肺间隔逐渐增宽。伤后7、14、28 d,治疗组肺组织病理评分[(2.60±0.63)、(4.05±0.20)、(3.80±0.23)分]分别低于对照组[(3.20±0.28)、(5.00±0.40)、(8.48±0.51)分]和盐水组[(3.20±0.16)、(5.20±0.33)、(8.20±0.52)分],差异均有统计学意义(t=-1.732、-1.837、-4.025、-5.745、-16.673、-15.556,P<0.05),除伤后7 d,治疗组与正常组[(2.20±0.23)分]比较差异无统计学意义(t=1.188,P>0.05),伤后14、28 d,治疗组均高于正常组,差异有统计学意义(t=12.438、9.798,P<0.05);(2)胶原沉积:伤后7 d,对照组和盐水组大鼠小气道周围胶原纤维沉积增加,随着观察时间的延长,肺间质逐渐出现大面积的胶原沉积。伤后7、14、28 d,治疗组的CVF[(5.22±0.26)%、(6.66±0.59)%、(4.86±0.44)%]均低于对照组[(6.21±0.31)%、(11.64±0.39)%、(36.17±2.24)%]和盐水组[(6.20±0.56)%、(11.11±1.01)%、(33.72±4.41)%],差异均有统计学意义(t=-4.893、-3.170、-8.476、-10.184、-27.491、-13.014,P<0.05),且除伤后28 d,治疗组CVF与正常组[(4.54±0.23)%]差异无统计学意义(t=3.860,P>0.05),伤后7、14 d的治疗组均高于正常组[(4.54±0.23)%、(4.54±0.23)%],差异均有统计学意义(t=1.275、6.646,P<0.05);(3)HYP表达:伤后7、14 d,治疗组[(0.77±0.01)、(0.97±0.01)μg/mL]、对照组[(0.93±0.01)、(1.27±0.18)μg/mL]和盐水组[(0.92±0.01)、(1.23±0.16)μg/mL]大鼠肺组织中HYP表达均高于正常组[(0.66±0.06)、(0.66±0.06)μg/mL],差异均有统计学意义(t=3.619、9.134、8.918、10.739、6.309、6.652,P<0.05),且伤后14、28 d治疗组[(0.97±0.01)、(0.83±0.02)μg/mL]显著低于对照组[(1.27±0.18)、(1.43±0.16)μg/mL]和盐水组[(1.23±0.16)、(1.42±0.15)μg/mL],差异均有统计学意义(t=-3.232、-3.230、-7.699、-7.913,P<0.05),伤后28 d,治疗组[(0.83±0.02)μg/mL]与正常组[(0.66±0.06)μg/mL]低于对照组[(1.43±0.16)μg/mL]和盐水组[(1.42±0.15)μg/mL],差异均有统计学意义(t=-7.699、-7.913、-9.326、-9.564,P<0.05),且治疗组与正常组间比较差异无统计学意义(t=5.720,P>0.05)。结论曲尼司特减轻了松木屑烟雾吸入性大鼠肺组织病理损伤程度,减少胶原沉积和HYP的表达。

Objective To observe the effect of tranilast on collagen synthesis in rats with lung injury induced by pine sawdust smoke,and to provide feasibility for prevention and treatment of smoke-induced pulmonary fibrosis.To provide feasibility for prevention and treatment of pulmonary fibrosis caused by smoking with tranilast.Method Seventy-two male SD rats were divided into normal group,control group,treatment group and saline group according to random number table method,with 18 rats in each group.Rats in control group,treatment group and saline group inhaled pine sawdust smoke for 15 minutes(smoking three times,each time for 5 minutes,once every 5 minutes).The control group received no treatment.Rats in the treatment group and the saline group respectively were injected intraperitoneally once a day with tranilast(200 mg·kg^(-1))and 0.5 mL 0.9%sodium chloride solution after 6 hours of smoke inhalation.Rats in normal group did not need injury and treatment.On the 7th,14th and 28th day after injury,the lung tissues of each group were stained by hematoxylin-eosin stain and Masson stain respectively,and the histopathological score and collagen volume fraction(CVF)were calculated,the content of hydroxyproline(HYP)in the lung tissues was determined by alkaline hydrolysis method,the data were analyzed by one-way analysis of variance and t test.Results(1)Hematoxylin-eosin stain:on the 7th day after injury,inflammatory cell infiltration,hyperemia and interstitial edema appeared in the lung tissues of both control group and saline group.With the extension of observation time,the inflammatory cell infiltration and bleeding in lung tissue increased,and pulmonary interval gradually widened.On the 7th,14th and 28th day after injury,the pathological scores of the treatment group[(2.60±0.63),(4.05±0.20),(3.80±0.23)points]were lower than those of the control group[(3.20±0.28),(5.00±0.40),(8.48±0.51)points]and the saline group[(3.20±0.16),(5.20±0.33),(8.20±0.52)points],the differences were statistically significant(t=-1.732,-1.837,-4.025,-5.745,-16.673,-15.556;P<0.05),except the 7th day,there was no statistically significant difference between the treatment group and the normal group[(2.20±0.23)points](t=1.188,P>0.05),on the 14th and 28th day after injury,the pathological scores of the treatment group were higher than those of the normal group,the differences were statistically significant(t=12.438,9.798;P<0.05).(2)Collagen deposition:on the 7th day after injury,collagen fiber deposition around the airway increased in control group and saline group.With the extension of observation time,large-scale collagen deposition appeared in the interstitial lung gradually.On the 7th,14th and 28th day after injury,CVF of treatment group[(5.22±0.26)%,(6.66±0.59)%,(4.86±0.44)%]were lower than those of control group[(6.21±0.31)%,(11.64±0.39)%,(36.17±2.24)%]and normal saline group[(6.20±0.56)%,(11.11±1.01)%,(33.72±4.41)%],the differences were statistically significant(t=-4.893,-3.170,-8.476,-10.184,-27.491,-13.014;P<0.05).Except the 28th day,there was no statistically significant difference between the treatment group and the normal group[(4.54±0.23)%](t=3.860,P>0.05).On the 7th,14th day after injury,CVF of the treatment group were higher than those of the normal group[(4.54±0.23)%,(4.54±0.23)%],the differences were statistically significant(t=1.275,6.646;P<0.05).(3)HYP expression:on the 7th and 14th day after injury,the expression of HYP in lung tissue of treatment group[(0.77±0.01),(0.97±0.01)μg/mL],control group[(0.93±0.01),(1.27±0.18)μg/mL]and saline group[(0.92±0.01),(1.23±0.16)μg/mL]were higher than those of normal group[(0.66±0.06),(0.66±0.06)μg/mL],the differences were statistically significant(t=3.619,9.134,8.918,10.739,6.309,6.652;P<0.05).Besides the 7th day,the treatment group[(0.97±0.01),(0.83±0.02)μg/mL]were lower than the control group[(1.27±0.18),(1.43±0.16)μg/mL]and saline group[(1.23±0.16),(1.42±0.15)μg/mL],the differences were statistically significant(t=-3.232,-3.230,-7.699,-7.913;P<0.05).On the 28th day after injury,the expression of HYP in treatment group[(0.83±0.02)μg/mL]and normal group[(0.66±0.06)μg/mL]were lower than that in control group[(1.43±0.16)μg/mL]and saline group[(1.42±0.15)μg/mL],the differences were statistically significant(t=-7.699,-7.913,-9.326,-9.564;P<0.05),and there was no statistically significant difference between the treatment group and the normal group(t=5.720,P>0.05).Conclusion Tranilast alleviates the pathological injury of lung tissue,collagen deposition and HYP expression in rats exposed to pine sawdust smoke.