大鼠心肌组织中网状纤维组织学构筑及增龄变化

Histological architecture of reticular fibers and age-related changes of myocardial tissue in rats

目的观察大鼠心肌组织发育过程中网状纤维的组织学构筑特点和增龄变化，为探讨心肌组织重构特点奠定基础。方法利用石蜡切片、Gomori银染，光镜下观察胎鼠（孕约19d）、新生（9d）、青年（8个月）、老年（14个月）sD大鼠心肌组织网状纤维的组织学构筑特点，Westernblotting检测Ⅲ型胶原蛋白随年龄变化的表达差异。利用图像分析系统对心室肌组织内网状纤维进行定量分析。结果网状纤维分为粗、细纤维，围绕在心肌细胞周围。胎鼠心肌细胞周围网状纤维呈细小线状或缺如，新生鼠的心肌细胞周围网状纤维逐渐增多，形成连续的网状纤维膜，相邻肌细胞之间出现间隙，随年龄而增宽，网状纤维近平行分支填充于间隙内。网状纤维所占面积百分比随年龄增加发生改变。Ⅲ型胶原（网状纤维）表达量随年龄增加发生改变，新生鼠到青年鼠是急剧增加阶段。结论大鼠心肌组织中网状纤维构成肌细胞周围的粗、细纤维鞘成分，并发出分支充填于心肌细胞之间和心肌细胞与间质之间的间隙内，Ⅲ型胶原蛋白量随年龄的变化发生改变。

Objective To observe the histological architecture of reticular fibers and age-related changes during development of rats, in order to establish abase for probing myocardial tissue remodeling characteristics. Methods Using technique of paraffin section, Gomori silver staining, the myocardial tissue of fetal rat （pregnant about 19d）, newborn rat （9d）, young rat （8m） and old rat （14m） were observed with light microscopy. The expression differences of Ⅲ type collagen were detected by Western blotting. The reticular fibers was quantitated with image analysis system, and the data were processed with SPSS statistical software. Results The reticular fiber could be divided to thin and thick fibers that encircled myoeytes. The reticular fibers around myoeyte showed thin string or absence in fetal rat. As for the newborn rat, the reticular fibers around myocytes gradually increased and formed continuous membranes, and some spaces that were full of branch of reticular fibers appeared between myoeytes. The area percentage of reticular fibers was gradually changed, l][ type collagen （reticular fiber） expression changed with aging, and sharply increased from newborn to young rat. Conclusion The reticular fibers are composed of thick or thin fihra sheaths around myocytes, and the branchs of reticular fibers are full of the space between myocytes or between myocytes and interstitium, and the expression of Ⅲ type collagen changes with aging.