重组人胸腺素α原对衰老和缺锌时免疫功能的影响

EFFECT OF HUMAN RECOMBINANT PROTHYMOSIN α ONTHE IMMUNE FUNCTION IN AGING AND ZINC DEFICIENCY

观察重组人胸腺素α原对衰老和缺锌所致的免疫功能低下的调节作用，并初步了解胸腺素α原在神经内分泌免疫网络中的作用和地位。方法：以自然衰老至１５月龄昆明小鼠为模型，随机分为两组，实验组每只鼠日腹腔注射胸腺素α原３００ｎｇ，对照组注射等量生理盐水，连续３周。取血测定溶血素和甲状腺激素水平，取胸腺和脾脏称重计算相应指数。另选４８只８０～９０ｇＷｉｓｔａｒ大鼠，随机分为：正常对喂、缺锌、缺锌补锌、缺锌补锌补α原四组。缺锌组饲以缺锌饲料，三周后，补锌组换饲正常对喂组饲料，两周后，取血测定血浆锌和皮质醇含量，取胸腺和脾脏称重，并制备脾脏细胞，测定ＣＤ４＋和ＣＤ８＋的比率。结果：胸腺素α原可以明显提高衰老小鼠胸腺的重量和指数，也可提高脾脏的重量和指数。同时显著升高特异性抗体溶血素的水平。胸腺素α原可明显提高血浆甲状腺激素Ｔ３和Ｔ４的水平。缺锌大鼠，食欲减退，生长发育迟缓。胸腺明显萎缩，同时血浆皮质醇的水平明显升高。缺锌后补充锌，与缺锌对照比较，胸腺重量和指数明显增加，但仍明显低于正常对喂组；锌补充不能降低血皮质醇水平。腹腔注射胸腺素α原后，不仅明显升高胸腺重量和指数，降低脾脏细胞中ＣＤ８＋的比例，而且也可调节因缺锌而升高的?

Abstract Objects: This study is designed to observe the effect of recombinant human prothymosin α on immune responses in 15monthold mice and Zndeficient rats． Methods: The 15monthold mice were divided randomly into normal and experimental groups． Three hundred nanograms prothymosin α were administered intraperitoneally for each mouse per day for three weeks in the experimental group． Saline was given for the control group．All mice were killed to assay the changes of weights of immune organs and hemolysin and thyroid hormones T3 and T4 in plasma three weeks later． Wistar rats were divided into pairfed control， Zndeficient control，Zndeficient＋Zn and Zndeficient＋Zn＋prothymosin α groups． One microgram prothymosin α was given intraperitoneally to each rat in the last group． Results: Compared with the control group in aging mice， the weight and index of thymus and spleen increased significantly after administering prothymosin α． Meanwhile， the plasma level of hemolysin was also increased markedly in the experimental group． It was unexpected that prothymosin α influenced the secretion of thyroid hormones like T3 and T4 In Zndeficient rats， thymus atrophied and cellular immune response decreased． After supplementation of Zn，the weight and index of thymus and spleen were enhanced． But the plasma cortisol resulted from Zn deficiency still remained high． Prothymosin α could not only increase the weight and index of thymus， but also decrease CD8＋ in spleen． The cortisol in plasma restored to nearly normal after administration of prothmosin α． Conclusion: Prothymosin α not only modulates the immune functions in aging and zincdeficient animals， but also regulates their endocrine status． It suggests that prothymosin α may play an important role in the neuroendocrineimmunological network． Key words: prothymosin α zinc deficiency aging immune function