Abstract: Objective To study the architecture of the testis lobule micrangium and its functional relationship in 30 adult Tibetan plateau sheep. Methods The ABS vascular proplasm, ink-gelatinum paraffin section and replica scanning electron microscopic methods were used.[WTHZ]Results The small arteries from the centripetal or centrifugal artery walked through the polygonal tissue space，and so as the distribution of the small veins. The interstitial capillary also went along the longitudinal wall of the seminiferous tubule and formed ladder-like capillary network, and give branches interconnected each other to form peritubular capillaries. The peritubular capillaries also formed interstitial capillary plexus around the Leydig cells; Moreover, the broad and different level communications were found in microvasculature around the seminiferous tubules of the testis lobule. There were obvious imprints of the smooth muscles on the surface of the casts of the intralobular small arteries, the interstitial arteriole and the precapillary arteriole. On the surface of the casts of the interstitial arteriole and the precapillary arteriole, there were obvious imprints of the endothelial nuclei as well.[WTHZ]Conclusion Several testis lobule micrangium structural features are abserved in Tibetan plateau sheep. It could be the result of their living in lower-oxygen on Tibetan plateau from generation to generation.

Key words: Testicular lobule, Capillary vessel, Ink-gelatinum paraffin section, Scanning electron microscopy, Tibetan plateau sheep