天府肉鸭胸腺淋巴细胞增殖与凋亡的增龄变化

Age-related Changes in the Lymphocyte Proliferation and Apoptosis of the Tianfu Duck Thymus

将65只天府肉鸭分为13个组,即22、24、26天胚龄,胚后0(新生雏)、3、5、8、14、17、20、26、29、32周龄;采用增殖细胞核抗原(PCNA)和半胱天冬酶-3(Caspase-3)免疫组织化学方法及光镜和电镜技术研究其胸腺胚胎及胚后发育期淋巴细胞增殖与凋亡的增龄变化规律。结果可见,各组胸腺中均可见PCNA和Caspase-3阳性反应淋巴细胞。胸腺小叶皮质和髓质淋巴细胞增殖率在22~26天胚龄逐渐下降,在胚后0~3,8~17,26~32周龄无明显变化,在5、8、20和26周龄显著下降;各组皮质淋巴细胞增殖率均明显高于髓质。胸腺小叶皮质和髓质淋巴细胞凋亡率在22~26天胚龄无明显变化,0~8周龄逐渐升高,8~17周龄恒定,20~32周龄呈上升趋势;各组皮质淋巴细胞凋亡率均明显高于髓质。凋亡淋巴细胞核呈多种形态,线粒体肿胀,嵴断裂;可见巨噬细胞吞噬凋亡小体的现象。淋巴细胞增殖与凋亡在天府肉鸭胸腺胚胎及胚后发育过程中普遍存在,具有明显增龄变化特性,协同参与胸腺发育和退化过程。

This experiment was conducted to study the age-related changes in the lymphocyte proliferation and apoptosis during the embryonic and post embryonic development of the Tianfu duck thymus.Sixty five Tianfu ducks were divided into 13groups as follows:22,24and 26days embryonic stage,and 0(neonatal stage),3,5,8,14,17,20,26,29and 32weeks after hatching.Proliferating cell nuclear antigen(PCNA)and Caspase-3immunohistochemisty and light,electron microscopy techniques were used in this study.The results showed that PCNA and Caspase-3positive lymphocytes were distributed in the thymus.The proliferative rates of thymic lymphocytes in the cortex and medulla decreased significantly from 22-26days embryonic stage,and kept stable from 0-3,8-17and 26-32weeks after hatching,but markedly decreased on 5,8,20and 26weeks after hatching.In the same age group,the proliferative rate of lymphocyte in the cortex was higher than that in the medulla.The apoptosis rates of thymic lymphocytes in the cortex and medulla kept unchanged from 22-26days embryonic stage,then increased from 0-8weeks after hatching, and kept stable from 8-17weeks,but rose continually from 20-32weeks.In the same age group, the apoptosis rate of lymphocytes in the cortex was higher than that in the medulla.The nuclei of apoptotic lymphocytes with swollen mitochondria and broken cristae mitochondriales presented different features.The apoptotic bodies were phagocytized by the macrophages.The proliferationand apoptosis of lymphocytes exist universally during the normal embryonic and post embryonic development of the Tianfu duck thymus which undergoes obvious age-related changes,and then supervises and controls the development and regression of this organ cooperatively.