鸭胸腺内Ghrelin免疫组织化学的定位分布及发育性变化

Immunohistochemical localization and developmental changes of ghrelin in the duck thymus

【目的】研究Ghrelin在鸭胸腺发育过程中的定位分布及变化规律，以期为进一步探讨Ghrelin对胸腺生理功能的影响提供形态学资料。【方法】选用不同发育阶段的天府肉鸭，胚胎期分7个组，即：14、16、18、20、22、24和26 d胚龄组；胚后期分12个组，即：新生雏、1、3、5、8、11、14、17、20、26、29和32周龄组。运用免疫组织化学技术及形态计量方法研究Ghrelin在鸭胸腺发育过程中的定位分布及变化规律。【结果和结论】Ghrelin免疫阳性细胞弥散分布于20 d胚龄至胚后32周龄的胸腺小叶皮质和髓质；阳性细胞呈圆形、卵圆形、星形或不规则形，主要为胸腺上皮细胞和巨噬细胞。阳性细胞数量在胚胎期无明显差异，在胚后胸腺继续发育期（新生雏～8周龄）和成熟期（11～17周龄）呈波浪状变化，在退化期（20～32周龄）呈下降趋势。说明在天府肉鸭胸腺个体发育中存在Ghrelin免疫阳性细胞，其数量表现出明显增龄变化特性，与胸腺退化密切相关。

[Objective] The immunohistochemical localization and developmental changes of ghrelin in the duck thymus were studied to provide the morphological effect of ghrelin on the physiological function of thymus.[Method] Tianfu ducks were divided into 19 groups as follows：7 groups in the embryonic peri-od （14, 16, 18, 20, 22, 24 and 26 days at embryonic stage ）, 12 groups after hatching （ at neonatal stage, 1, 3, 5, 8, 11, 14, 17, 20, 26, 29 and 32 weeks）.The immunohistochemical method associat-ed with morphometric analysis was used .[Result and conclusion] The ghrelin immunoreactivity （-ir） cells with round, ovoid, stellate and irregular aspects were maily thymic epitheilial cells and macropha-ges, and diffusely distributed in the thymic cortex and medulla from embryonic 20 days to 32 weeks after hatching .The number of ghrelin-ir cells in the thymic cortex and medulla was unchanged during the em-bryonic development , presenting a wave-changed pattern during the continuous development （ from neo-natal stage to 8 weeks after hatching ） and matured periods （ from 11 to 17 weeks after hatching ） , which decreased during the involution stage （ from 20 to 32 weeks after hatching ） .These results suggested that ghrelin-ir cells existed in the duck thymus and their numbers exhibited obvious age -related changes ,which can be closely related to the involution of the duck thymus .