心脏Telocytes在年老大鼠心脏的分布

Distribution of cardiac telocytes in the aged rat heart

目的探讨心脏Telocytes(CTs)在年老大鼠心脏的形态、分布及与年青心脏比较的异同。方法使用透射电子显微镜、生物测量、免疫荧光染色等技术,对24月龄年老大鼠心脏的心房部分、心室中间部分及心尖部分的代表性横切面中,CTs的形态、分布与细胞密度进行半定量分析。结果年老心脏3个代表性横切面的心肌细胞间隙和微血管周边均存在许多CTs,上述3个不同部位的CTs的形态指标的半定量分析值十分接近,差异没有统计学意义。经分离的年老心脏CTs与年青心脏一样表达c-Kit和CD34。对3个代表性横切面CTs细胞密度的半定量分析结果显示,年老大鼠心房部分的CTs密度[(47.65±4.01)个/mm^2]显著高于心尖部分[(33.68±2.53)个/mm2]和中间部分[(26.49±2.11)个/mm^2](P<0.05)。年老心脏CTs在上述区域分布的差异,与我们前期所观察到的年青大鼠心脏相应区域CTs的分布规律相一致[7],但年老心脏上述3个区域CTs的密度均显著性高于年青心脏对应区域(P<0.05)。结论年老心脏存在CTs,其心房部分的CTs密度显著高于心尖部分和心室中间部分,该分布规律与年青大鼠相一致,但年老心脏上述区域CTs的密度显著高于年青心脏。

Objective To observe the morphology and distribution of cardiac Telocytes（ CTs） in the aged rat heart and the difference compared with young rat heart. Methods The transmission electron microscopy combining bio-image analysis and immunofluorescence staining were applied to analyze the morphology and distribution of CTs in the atrium,medium and apex part of 24-month-old rat heart semiquantitatively. Results A lot of cells with unique morphology of CTs were found in interstitial tissue of cardiac myoctyes and microvessels in the atrium,medium and apex part. The morphology parameters of CTs were similar in the three representative dimensions of heart. The difference is not statistic significance.The immunofluorence staining documented that aged CTs as well as young CTs expressed c-Kit and CD34. In aged heart,the CT density in the atrium part（ 47. 65 ± 4. 01 cells / mm^2） was significantly higher than that of the apex part（ 33. 68 ±2. 53 cells / mm^2） and the medium part（ 26. 49 ± 2. 11 cells/mm2）（ P 〈 0. 05）. In addition,it was found that the distributional pattern of CTs in the three representative dimensions of aged heart was similar to that of young heart[7].However,the CT density in the three representative dimensions of aged heart is significantly higher than that of the parallel areas of young heart（ P 〈 0. 05）. Conclusion CTs are found in the aged rat heart. The CTs density of the atrium part is significantly higher than that of the apex part and the medium part in aged heart. In addition,the distributional pattern of CTs in aged heart is similar to young heart. However,the CTs density of aged heart in atrium,medium and apex part is significantly larger than that of parallel areas of young heart respectively.