脂联素对大鼠慢性间歇性低氧所致心肌重塑的影响

目的：探讨慢性间歇性低氧（chronic intermittent hypoxia，CIH）对心肌重塑的影响及脂联素（adiponectin， Ad）的干预作用。方法将45只Wistar大鼠随机分为3组：正常对照组（NC），CIH组和CIH＋Ad组。CIH 35d后，使用马松染色分析方法检测左室纤维化程度及使用Western blot方法来衡量Ⅰ型胶原蛋白、Ⅲ型胶原蛋白和TGF-β/smad2/3通路蛋白的表达。通过RT-PCR方法来研究基质金属蛋白酶-2（MMP2）/基质金属蛋白酶的组织抑制剂-2（TIMP-2）的mRNA表达比值情况。结果慢性间歇性低氧处理后，CIH组左心室的纤维化程度显著高于NC组和CIH＋Ad组（P＜0.05），但NC组和CIH＋Ad组之间差异具有统计学意义（P＜0.05）。CIH组Ⅰ型胶原蛋白和Ⅲ型胶原蛋白和MMP2/TIMP-2的mRNA比值表达最高，NC组表达最低，CIH＋Ad组居中，3组之间均差异具有统计学意义（P＜0.05）。TGF-β/smad通路蛋白在CIH组中表达显著高于NC组和CIH组（P＜0.05），且NC组和CIH＋Ad组差异具有统计学意义（P＜0.05）。结论慢性间歇性低氧可引起左室重构，而Ad可能通过抑制TGF-β/smad2/3通路改善此损害。

Effects of adiponectin on myocardiac remodeling induced by chronic intermittent hypoxia in Wistar rats

ObjectiveTo investigate the effects of chronic intermittent hypoxia （CIH） on myocardiac remodeling and intervention role of adiponectin（Ad） in the process.Methods A total of 45 Wistarrats were randomly divided into3 groups： normal control （NC） group, CIH group and CIH＋Ad group （10μg Ad injection through caudal vein twice per week, for 5 weeks）. After 35 days’ CIH exposure （in a chamber with 60 s nitrogen infusion to reduce theoxygen concentration to 5% followed by another 60 s oxygen infusion to increase theconcentration to 20% for totally 8 h of each day）,Masson analysis was used to detect the left ventricular fibrosis, and Western blot was used to measure the protein expression of collagenⅠ, collagenⅢ and pathway proteins TGF-β/smad2/3. RT-PCR was used to study the expression of matrix metalloproteinase-2 （MMP-2） and tissue inhibitor of metalloproteinase-2 （TIMP-2）.Results After CIH exposure, the left ventricular fibrosis was significantly more severe in CIH group than in NC groupand CIH＋Ad group （P〈0.05）, and there was statistical difference between the 2 latter groups （P〈0.05）. In addition, the protein expression of collagenⅠ and collagenⅢ and the mRNA expression of MMP-2 and TIMP-2 were the highest in CIH group, the lowest in NC group, and CIH＋Ad group in the middle. There was a significant difference among 3 groups （all P〈0.05）. The pathway proteins TGF-β/smad2/3 were most significantly expressed in CIH group （P〈0.05） , but there was still significant difference in their expression between NC group and CIH＋Ad group （P〈0.05）.Conclusion CIHmay cause may left ventricular remodeling, while Ad supplementmay ameliorate the impairmentvia inhibiting TGF-β/smad2/3 pathway.