不同生态环境不同品种绵羊卵巢微动脉解剖学特征

Comparison of anatomical characteristics of ovarian arterioles among sheep breeds in different ecological environments

从青海西宁、内蒙古赤峰、浙江桐乡和山东菏泽分别采集高原型藏羊、敖汉细毛羊、湖羊和小尾寒羊卵巢各20枚,利用微血管立体构筑和扫描电镜(SEM)技术相结合的方法,研究不同品种绵羊卵巢微动脉的构筑及超微结构特征。结果显示,绵羊卵巢微动脉呈迂曲盘旋的螺旋状,卵巢门动脉经3~4次分支后发出毛细血管;在卵巢微动脉的Ⅱ~Ⅳ级分支表面均有梭形凹痕,呈典型的"树皮样"或"波浪状";在毛细血管前微动脉处有多个与微动脉横轴平行或呈一定夹角的环行缩窄。比较发现,高原型藏羊的卵巢微动脉螺旋程度更高,且各级微动脉的管径均较粗,"树皮样"压痕和环形缩窄较深且密;小尾寒羊卵巢微血管网更密集、分支更多。研究认为,高原型藏羊卵巢微动脉的解剖学特征,有利于增加卵巢内各部分的氧供,调节和分配血液供应以适应高原环境,而小尾寒羊卵巢更密集的微血管网可能是其排卵数高的生理学基础之一。

Twenty ovary samples of Tibetan sheep, Aohan fine wool sheep, Hu sheep and small-tailed Han sheep were collected in their original areas including Xining Qinghai, Chifeng Inner Mongolia,Tongxiang Zhejiang and Heze Shandong, respectively.The microvascular casting tech-nology and scanning electron microscopic (SEM) method were used to research the three-dimen-sional construction and ultrastructural features of sheep ovarian arterioles in different breeds.The results demonstrated that the ovarian arterioles of sheep were twisted and spiraled. In general ar-teries at ovarian hilum could emit capillaries through 3-4 branches. Ovary Ⅱ-Ⅳ level branch of ar-terioles surface had spindle dent,appearing as a typical “bark” or “wave” structure,sometimes some “long” or “flat oval” indentation of the nucleus can be seen. At the precapillay arterioles, there had some ringed constrictions that were parallel or angled to the transverse axis of the arteri-oles.The comparison found that the ovarian arterioles of Tibetan sheep had a higher degree of spi-ral, and the diameter of all level arterioles was thicker,the "bark-like", indentation and ringed con- strictions were deeper and denser;the ovarian microvascular network of small-tailed Han sheep was more dense and more branches.The study demonstrated that the anatomical characteristics of ovarian arterioles in Tibetan sheep were favorable for adapting to the plateau environment with in-creasing the oxygen supply ,regulating and distributing the blood supply to all parts of the ovary. The denser ovarian microvascular network in small-tailed Han sheep might be one of the physio-logical basis of high ovulation number.