鲑鱼鱼白DNA对老龄小鼠胸腺淋巴细胞构成的影响

目的：探讨外源性核酸对自然衰老小鼠CD3^ 、CD3^ CD4^ 和CD3^ CD8^ 胸腺淋巴细胞构成的影响。方法：10月龄雌性Balb/c小鼠按体质量随机分为高剂量组、低剂量组和对照组。5周后，测定胸腺脏器指数；胸腺组织切片后以Image-pro Plus专业图像分析系统（4.0版）计数胸腺细胞；采用直接免疫荧光流式细胞术检测老龄小鼠胸腺细胞CD3^ 、CD3^ CD4^ 和CD3^ CD8^ 的表达情况。结果：鲑鱼鱼白DNA提取物对小鼠的体质量、胸腺质量和胸腺指数均没有影响，但可增加小鼠的胸腺皮质和髓质细胞数量，并提高CD3^ 、CD3^ CD4^ 和CD3^ CD8^ 淋巴细胞的比例，而对CD3^ CD4^ 和CD3^ CD8^ 淋巴细胞的比值没有影响。结论：补充鲑鱼鱼白DNA可能改变自然衰老Balb/c小鼠胸腺细胞的构成，使胸腺有效细胞数量增加，从而可能延缓胸腺的退化萎缩。

Effect of Salmon milt DNA on constitution of thymus lymphocytes in aged mice

Objective To study the effect of exogenous nucleic acid e xtract on the constitution of thymus lymphocytes including CD3 +, CD3 +CD4 + and CD3 +CD8 + lymphocytes in natural aging mice.Methods Fema le Balb/c mice aged 10 months were divided rando mly into three groups acco rding to their weights. They were high dosage group, low dosage group and control grou p. After five weeks, their thymus indices were measured and the lymphocytes were counted using Image Pro Plus (version 4.0) software in the thymus section. The expression of CD3 +, CD3 +CD4 + and CD3 +CD8 + thymocytes in aged mice wer e determined by direct immunofluorescence flow cytometry.Results There were no differences with the body weight, thymus weight and thymus indic es among the groups. Salmon milt DNA extract increased the cortical cells and me dullar cells in the thymus. The proportion of CD3 +, CD3 +CD4 + and CD3 +CD8 + phenotype thymocytes were also increased due to Salmon milt DNA extract. But the ratios of CD3 +CD4 + and CD3 +CD8 + lymphocytes showed no significant d ifference among the groups.Conclusion Our results suggested tha t supplementation of Salmon milt DNA may postpone the age related involution in thymus through changing the constitution of lymphocytes and increasing effectiv e lymphocytes.