目的 探索细胞外基质相关蛋白在高原地区藏绵羊与小尾寒羊睾丸的分布及组织化学特征。方法 应用组织化学方法、Image-Pro Plus (IPP)图像分析技术及电子显微镜，观察比较藏绵羊（4只）与小尾寒羊（5只）睾丸组织化学特点及层黏连蛋白（LN）、Ⅳ型胶原（Col Ⅳ）和硫酸乙酰肝素糖蛋白（HSPG）的分布特征。结果 与小尾寒羊睾丸相比，藏绵羊生精小管基膜及间质组织内胶原纤维及网状纤维丰富；过碘酸-雪夫（PAS）及阿利新蓝-过碘酸-雪夫（AB-PAS）染色显示，藏绵羊睾丸间质血管及生精小管固有膜阳性反应更为丰富。免疫组织化学显示，Col Ⅳ在藏绵羊及小尾寒羊生精小管上皮均呈阳性表达，LN在藏绵羊Sertoli细胞及管周肌样细胞呈弱阳性表达，而在小尾寒羊Sertoli细胞、Leydig细胞及管周肌样细胞为中等阳性表达；HSPG在藏绵羊及小尾寒羊肌样细胞均呈强阳性表达，而在Sertoli细胞及Leydig细胞均为弱表达。免疫组织化学图像分析结果显示，藏绵羊睾丸组织中Col Ⅳ和LN的分布显著低于小尾寒羊睾丸组织（P<0.01），HSPG检测结果则显著高于小尾寒羊睾丸组织（P<0.01）。电子显微镜下观察，藏绵羊及小尾寒羊生精小管固有膜可见发育良好的生殖上皮基膜以及1层明显的Ⅰ型胶原纤维，藏绵羊固有膜胶原纤维层丰富且Leydig细胞内脂滴明显。 结论 高原环境下藏绵羊睾丸固有膜及间质结缔组织较为丰富，在一定程度上影响了生精上皮发育；藏绵羊睾丸间质血管壁及生精小管固有膜AB-PAS阳性反应增强与Leydig细胞分泌功能相关，小尾寒羊睾丸组织LN表达显著增加及HSPG显著降低与生精上皮发育程度关系密切。

Objective To compare the distribution and histochemical characteristics of extracellular matrix components in the testis between 4 Tibetan sheep and 5 small-tail Han sheep from plateau at the same age. Methods Histochemistry and transmission electron method were used to characterize the microstructure and ultrastructure of the two kinds sheep testis. Image-Pro Plus(IPP) statistics methods were used to identify the integrated absorbance for laminin(LN), type Ⅳ collagen(ColⅣ) and heparan sulfate proteoglycans(HSPG) distribution investigation by immunohistochemistry. Results The light microscopy observation showed that compared with the testis of the small-tail Han sheep from plateau, the collagen and reticular fibers were richer in interstitial of the Tibetan plateau sheep. The periodic acid-schiff(PAS) and Alcian blue-periodic acid schiff(AB-PAS) staining positive reactions were more obvious in interstitial basement and blood capillary of the Tibetan plateau sheep testis. Immunostaining analysis showed that the Col Ⅳ was present strongly in the seminiferous epithelium of both the Tibetan plateau sheep and the small-tail Han sheep. The expression of LN in the Sertoli cells and peritubular myoid cells of the Tibetan plateau sheep testis was weak but moderately positive in the Sertoli cells, the Leydig cells and peritubular myoid cells of the small-tail Han sheep testis. In the both kinds of sheep testis, the expression of HSPG was especially strong in the peritubular myoid cells but weak in the Sertoli cells and Leydig cells. The integrated absorbance of Col Ⅳ and LN expression was significantly lower in testis of the Tibetan sheep than the smalltail Han sheep (P<0.01）, but the average absorbance of HSPG expression was markedly higher than it (P<0.01). Electron micrographs of portion of the seminiferous tubule in the both of the testis showed elaborately developed tunicae propria with a well defined epithelial basal lamina and a distinct layer of typeⅠcollagen fibrils. The collagen fibrils were found around the interstitial blood capillaries and the abundant Lipid droplets in the Leydig cells of the small-tail Han sheep testis from plateau. Conclusion In plateau environment, the connective tissue in the tunicae propria and interstitial tissue of the Tibetan sheep testis is more abundant, and partly affect the development of the seminiferous epithelium. The AB-PAS positive reaction in interstitial basement and the wall of blood capillary in the Tibetan plateau sheep testis are closely related to the secretory function of the Leydig cells. The integrated absorbance of LN expression is significantly higher and HSPG is lower markedly in testis of the smalltail Han sheep testis, which is very important to the development degree of seminiferous epithelium.