Aging or senescence is a process in which individuals undergo an exponential decline in vitality, leading to death. Recent years,much progress on the molecular mechanisms underlying senescence have been made. (1) Some...Aging or senescence is a process in which individuals undergo an exponential decline in vitality, leading to death. Recent years,much progress on the molecular mechanisms underlying senescence have been made. (1) Some senescence-related gene such as SEN6A,hic-5,din1 and MORF 4 have been clarified; (2) In 1997, through a set of experiments sponsered by scientists of Department of Biology Massachusetts Institute of Technology, it was found that the accommulation of extrachromosomal rDNA circles (ERC) in budding yeasts nucleolus is responsible for cell-senescence and the researchers propose that when enough of these circles accumulate, they clog the nucleus and prevent the cell from reading or replicating its genome, causing it to stop dividing and ultimately to die; (3) In another work finished by National Institute on Aging and the Geron biotech company of Melo, it was proved that a cells biological clock,which tells the cell how and how many times to divide, lies in its telomeres, little bits of DNA that coat the tips of the chromosome and it was clarified that a powerful enzyme,telomerase, with the potential to rejuvenate the human bodys aging tissues could effectively extend the shortened telomere . Although there is a long way to go, scientists still believe that it will be made reality in the future to greatly extend the life-span of human.展开更多
一氧化氮(nitric oxide,NO)是一种新型的细胞信使分子,它在调节心血管系统、神经系统和免疫功能方面起着重要的作用.测定组织细胞 NO 的含量对于探讨NO 的生理功能具有重要的意义.该文简要介绍了应用化学发光法、微盘测定法、放射强度...一氧化氮(nitric oxide,NO)是一种新型的细胞信使分子,它在调节心血管系统、神经系统和免疫功能方面起着重要的作用.测定组织细胞 NO 的含量对于探讨NO 的生理功能具有重要的意义.该文简要介绍了应用化学发光法、微盘测定法、放射强度测定法和分光光度法检测组织细胞 NO 的含量.展开更多
Urotensin-Ⅱ is a vasoactive ’somatestatin-like’ cyclic peptide. Recently, human urotensin-Ⅱ has been cloned and demonstrated to be the most potent vasoconstrictor identified so far. The receptor of urotensin-Ⅱ ha...Urotensin-Ⅱ is a vasoactive ’somatestatin-like’ cyclic peptide. Recently, human urotensin-Ⅱ has been cloned and demonstrated to be the most potent vasoconstrictor identified so far. The receptor of urotensin-Ⅱ has now been identified as the orphan receptor GPR 14 . This peptide may influence cardiovarscular homeostasis, pathology and also influence respiratory system, central nervous system and endocrine function.展开更多
文摘Aging or senescence is a process in which individuals undergo an exponential decline in vitality, leading to death. Recent years,much progress on the molecular mechanisms underlying senescence have been made. (1) Some senescence-related gene such as SEN6A,hic-5,din1 and MORF 4 have been clarified; (2) In 1997, through a set of experiments sponsered by scientists of Department of Biology Massachusetts Institute of Technology, it was found that the accommulation of extrachromosomal rDNA circles (ERC) in budding yeasts nucleolus is responsible for cell-senescence and the researchers propose that when enough of these circles accumulate, they clog the nucleus and prevent the cell from reading or replicating its genome, causing it to stop dividing and ultimately to die; (3) In another work finished by National Institute on Aging and the Geron biotech company of Melo, it was proved that a cells biological clock,which tells the cell how and how many times to divide, lies in its telomeres, little bits of DNA that coat the tips of the chromosome and it was clarified that a powerful enzyme,telomerase, with the potential to rejuvenate the human bodys aging tissues could effectively extend the shortened telomere . Although there is a long way to go, scientists still believe that it will be made reality in the future to greatly extend the life-span of human.
基金国家自然科学基金资助项目 (No .39870 359)广东省自然科学基金资助项目 (No.990 958)教育部留学回国人员科研基金资助项目 (No.1 998679)
文摘Urotensin-Ⅱ is a vasoactive ’somatestatin-like’ cyclic peptide. Recently, human urotensin-Ⅱ has been cloned and demonstrated to be the most potent vasoconstrictor identified so far. The receptor of urotensin-Ⅱ has now been identified as the orphan receptor GPR 14 . This peptide may influence cardiovarscular homeostasis, pathology and also influence respiratory system, central nervous system and endocrine function.
