巴西红耳龟血液系统特殊的抗缺氧机理研究

There are increasing studies showing that the biological aging are mainly induced by a variety of irreparable damages of biochemical stresses in relevance to energy metabolism. This project suggests for the first time to study the anti-aging as well as anti-stress advantages of the turtle-related animals for improving the bionic health for human. The specific physiological structure and metabolic pattern of turtles let them suvive under severe enviromental stresses such as low temperature, anoxic condition and stavation. Current explanation referring to such characteristics of turtles are 1) to reduce basal metabolism; 2) to use anoxic breath (glycolysis), for anaerobic suvive. In our early studies, an extremly high creatine kinase activity and other odd phenomenons were found in turtles' blood system. Thus a "microbe-like energy-producing erythrocyte hypothesis" was proposed. This project, based on our early biochemical-aging mechanism studies, is planning to search for direct energy-producing evidence of erythrocytes of red-eared slider (Trachemys scripta), to apply proteomic and bio-informatic techniques to identify energy-manufacturing machinary, proteins or enzymes, on the erytherocyte plasma membrane of turtles, and to measure physicochemical indexes related to anoxia-tolerance and energy supply metabolism in turtle's tissue as well as blood system. We hope that this study, in relevance with anti-fatigue, anti-subhealth, improving sport capability and anti-aging, to investigate turtles' anti-reperfusion- and hibernation-related physiology, may obtain valuable data for humans life and health.

大量研究表明，与能量代谢相关的种种生化应激损伤及其失修性累积是生物体衰老的关键起因。本项目拟通过对龟类等长寿动物特殊的抗缺氧、抗应激供能机制的研究，展开针对健康长寿问题的仿生学探索。龟类独特的生理结构和代谢方式使其能在低温、缺氧、禁食等严酷的外部环境条件下得以长期生存。现有的研究认为，龟类主要是靠1）降低基础代谢；2）采用缺氧呼吸(糖酵解)；来实现缺氧甚至无氧生存。本室的前期研究发现了龟血中极高的肌酸激酶活性等异象，进而提出龟类的"微生物样红细胞产能假说"。本项目拟在本室以往关于衰老生化机理研究的基础上：探索巴西红耳龟红细胞产能的直接证据；以蛋白质组学和生物信息学技术研究鉴定其质膜上的产能蛋白；通过检测相关的理化指标研究其特殊的抗缺氧生理生化，及其供能机制。希望通过探索龟类与冬眠相关的抗缺氧（血）再灌注机理，对人类的抗疲劳、抗亚健康、提高运动成绩以至抗衰老研究提供有价值的科学信息。

本项目的核心部分基本按原计划进行。获得了一批宝贵的与龟血冬眠缺氧应激相关的生物医学信息和原创成果，也积累一些与龟类抗缺氧供能研究相关的经验教训。研究发现了龟类血液中与缺氧相关的能量代谢关键酶乳酸脱氢酶和肌酸激酶的活性特别高，是人体血液酶活的几十倍甚至更高。意味着缺氧冬眠或其它恶劣条件下龟类可能具有产能供能的特殊生理生化机制。研究发现巴西红耳龟的有核红细胞有表达产能蛋白质的特质，在其红细胞膜上存在着ATP合成酶亚单位、细胞色素C1和ND4L。研究证明龟血红细胞膜能够直接产能，并与其红细胞膜内外的氢离子梯度的变化相匹配。研究表明龟类冬眠缺氧可依靠“长距离-穿透-输送”能力极强的肌酸磷酸实现大脑与心脏的局部供能，从而有效保护身体的重要器官。该机理可以为人类的手术医疗、增强健康、驱除疲劳、以至延年益寿、太空冬眠旅行提供重要的启示和开辟广阔的应用前景。. 总体来说，在本课题经费的支持下实验做了很多，数据也积累了不少，但与原计划直接对号入座的研究并不太理想，例如动物体内肌酸含量的准确测定是本研究预先没有想到的瓶颈，因此拖慢了实验进度和对乌龟抗缺氧供能机理关键信息的探究。