血小板衍生生长因子和Ⅰ型胶原在饮水砷暴露小鼠肝组织中的表达

Expression of Platelet-derived growth factor and Collagen type I in hepatic tissue in oral drinking arsenic exposed mice

目的探讨血小板衍生生长因子（PDGF）和Ⅰ型胶原（Col～I）在饮水砷暴露小鼠肝组织中的表达及其意义。方法50只昆明种雄性小鼠被分成对照组、iAs^3＋组、iAs^5＋组，分别饮用自来水，亚砷酸钠溶液（NaAsO2，含砷离子300mg／L），砷酸钠溶液（Na2HAsO2·7H20，含砷离子300mg／L）。10个月后处死小鼠，使用全自动生化分析仪检查肝功能，包括血清丙氨酸转氨酶（ALT）、天冬氨酸转氨酶（AST）、球蛋白（GLB）；Masson染色肝组织，检测单位视场内的纤维面积；免疫组化（SABC）法检测肝组织中PDGF和Col—Ⅰ的表达。结果④对照组、iAs^3＋组、iAs^5＋组，血清ALT水平分别为（36．67±3．51）、（61．46±13．85）、（43．31±4．21）U／L，组间比较差异有统计学意义（F=6．56，P〈0．05），iAs^3＋组明显高于对照组（P〈0．05）；血清AST水平分别为（135．00±20．42）、（510．86±59．01）、（258．93±22．40）U／L，组间比较差异有统计学意义（F=83．33，P〈0．05），iAs^3＋、iAs^5＋组均明显高于对照组（P〈0．05），iAs^3＋组明显高于iAs^5＋组（P〈0．05）；血清GLB水平分别为（20．86±0．61）、（26．94±3．73）、（24．59±5．27）g／L，组间比较差异无统计学意义（F=2．80，P〉0．05）。②光镜下染砷组小鼠肝组织出现明显的细胞变性、坏死、再生，汇管区炎细胞浸润，纤维增生。对照组（0．069±0．013）、iAs^3＋组（0．192±0．108）和iAs^5＋组（0．143±0．122）单位视场内的纤维面积组间比较，差异有统计学意义（F=1．91，P〈0．05），iAs^3＋组明显高于对照组（P〈0．05）。③对照组、iAs^3＋组、iAs^5＋组PDGF、Col—Ⅰ光密度值分别为202．788±7．462、174．382±7．706、177．644±7．811，200．11±7．46、176．47±10．20、177．38±7．95，组间比较差异均有统计学意义（F值分别为102．91、78．51，P均〈0．05），与对照组比较，iAs^3＋、iAs^5＋组PDGF、Col—Ⅰ光密度值明显降低（P〈0．05），表明肝组织内PDGF、Col—Ⅰ表达明显增多，且PDGF在汇管区、间隔细胞、窦旁细胞内均有表达，而Col—Ⅰ表达广泛分布于血管及胆管周围，并自门管区向肝实质内延伸形成纤维间隔。结论长期饮水砷暴露，可导致慢性肝脏损伤、肝纤维化形成。PDGF、Col—Ⅰ在砷致小鼠肝纤维化形成中起重要作用。

Objective To study the expression and its significance of Platelet-derived growth factor（PDGF） and Collagen type Ⅰ （Col- Ⅰ ） mRNA in hepatic tissue in mice exposed to arsenic in drinking water. Methods Fifty mice were divided into control group, sodium arsenite group（iAs^3＋ group, 300 mg/L） and sodium arsenate group （iAs^5＋ group, 300mg/L） at random. The micewere sacrificed after 10 months for liver function test （ALT, AST and GLB examined by automatic biochemical analyzer） and pathologic examinations. Masson staining and immunohistochemical SABC methods were used. Through the result of Masson staining fibrosis semi-quantitative analysis of the fibrosis number was carried out in the per unit area. Using immuonhistochemical SABC methods, the expression of PDGF and Col- Ⅰ was detected. Results （1）Serum ALT was statistically significant among control group[ （36.67 ± 3.51 ） U/L], iAs^3＋ group[ （61.46 ± 13.85） U/L] and iAs^5＋ group[ （43.31 ± 4.21 ） U/L, F=6.56, P 〈 0.05], especially between the control and iAs^3＋ group （P 〈 0.05 ） ; Serum AST had a statistical significance among control group [ （135.00 ± 20.42）U/L], iAs^3＋ group [ （510.86 ± 59.01 ）U/L] and iAs^5＋ group[ （258.93 ± 22.40） U/L, F = 83.36, P 〈 0.05] ; Serum GLB had no statistical significance among control group[ （20.86 ± 0.61 ）g/L], iAs^3＋ group[ （26.94 ± 3.73）g/L] and iAs^5＋ group [ （24.59 ± 5.27）g/L, F = 2.80, P 〈 0.05 ]. （2）Masson staining revealed notable liver cell necrosis, regeneration, infiltration of inflammatory cells in portal area. Masson staining Semi-quantitative results showed significantly increasing size of fibrosis in model group. Compared with control group（0.069 ± 0.013） and iAs^5＋ group（0.143 ± 0.122）, fiber hyperplasia of iAs^3＋ group（0.192 ± 0.108） had statistical significance （F = 1.91, P 〈 0.05）. （3）Immunohistochemistry results showed higher expression of PDGF in the portal area, sepetal and preisinus cells in model group. The heavy expression of Col- Ⅰ distributed in the surrounding of blood vessels and bile duct and along portal wall extensting to the liver in model group. Semi-quantitative results showed that PDGF among control group（202.79 ± 7.46）, iAs^3＋ group（174.38 ± 7.71 ） and iAs^5＋ group（177.64 ± 7.81 ） had a statistical signifieanee（F= 102.91, P〈 0.05）; Col-Ⅰ had a statistical signifieanee among eontrol group（200.11 ± 7.46）, iAs^3＋ group （ 176.47 ± 10.20） and iAs^5＋ group （ 177.378 ± 7.948, F = 78.51, P 〈 0.05）. Conclusions Exposed in oral drinking arsenic, mice can develop hepatic injury and hepatic fibrosis. The PDGF and Col-Ⅰ play significant effects on the process of hepatic fibrosis caused by oral drinking arsenic exposed mice.