不同日龄滩羊皮肤组织化学特征比较

为比较2、35日龄滩羊皮肤毛囊的发育特点与血管内皮生长因子（vascular endothelial growth factor，VEGF）和血管内皮生长因子受体2（vascular endothelial growth factor receptor 2，VEGFR2）的分布特征，探究出生后滩羊被毛生长发育的变化特点，试验应用常规HE染色及改良Masson胶原纤维染色、Gomori银氨法染色、磷钨酸染色等特殊染色观察2与35日龄滩羊皮肤组织结构特点；应用免疫组织化学法结合免疫荧光染色法观察VEGF及VEGFR2在2与35日龄滩羊皮肤组织中的分布定位，并用IPP图像分析软件进行定量分析。结果显示：与2日龄滩羊皮肤组织比较，35日龄滩羊表皮与真皮间界限更加清晰，毛囊结构发育完整；毛囊密度显著降低（P<0.05）；胶原纤维与弹性纤维含量增加，形成网格状分布。免疫组化及免疫荧光结果显示，VEGF及VEGFR2在滩羊皮肤表皮及毛囊外根鞘、皮脂腺上均有表达。统计表明，VEGF及VEGFR2在2日龄滩羊皮肤组织中的表达量均显著高于35日龄（P<0.05）。综合上述结果，滩羊毛囊发育过程中，胶原纤维和弹性纤维增加明显；VEGF与VEGFR2通路在毛囊角质形成中起直接调节作用。

Comparison of Skin Histochemical Characteristics in Tan Sheep at Different Ages

This study aimed to investigate developmental characteristics of hair follicles and the distribution of vascular endothelial growth factor (VEGF) and vascular endothelial growth factor receptor 2 (VEGFR2) in 2-day-old and 35-day-old Tan sheep's skin.The cytochemical characteristics of the skin were observed under the microscopy by HE, modified Masson, Gomori and PATH staining, while the expression of VEGF and VEGFR2 were investigated by histochemical analyses using immunohistochemical and immunofluorescence, IPP image analysis software was used for quantitative analysis.The results showed that compared with 2-day-old Tan sheep, the hair follicle of 35 days was developed well, the boundary between epidermis and dermis was clearer, and the collagen and elastic fibers increased and forming a grid-like distribution, and the density of hair follicles was decreased (P<0.05).The expression of VEGF and VEGFR2 were strong in epidermis, outer root sheath and sebaceous glands of the skin.The average optical of VEGF and VEGFR2 was higher in 2-day-old than in 35-day-old Tan sheep skin tissues(P<0.05).Therefore, the collagen and elastic fibers increased obviously during the development of Tan sheep hair follicle;The pathway of VEGF and VEGFR2 played a direct regulatory role in hair follicle keratinization.