【作者】 刘芳；

【导师】 罗琼； 李世敏；

【作者基本信息】 武汉大学 ， 劳动卫生与环境卫生学， 2005， 硕士

【摘要】 研究表明,蛋白质分子中隐含着活性片段,它们对人体具有多种特殊的生理调节作用。这些生物活性肽进入人体内后,可产生类似激素活性物质的作用。目前从天然蛋白质中获得各种功能性肽(Functional Peptides):如促钙吸收肽、降血压肽、免疫调节肽等。其中,降血压肽(Anti-hypertension Peptides,ACEIP)是一类能够降低高血压病人血压的多肽总称。它是血管紧张素转化酶(angiotensin-converting enzyme,简称ACE)的抑制剂,可通过抑制人体血管紧张素Ⅱ的生成而达到降低血压目的。血管内皮细胞(vascular endothelial eells,VEC)能分泌多种调节血管功能的活性物质,它们与心血管疾病有密切关系。近年来的研究表明:原发性高血压的早期就已出现血管内皮功能的障碍,从而导致某些舒血管物质,如一氧化氮(Nitric oxide,简称NO)释放减少,某些缩血管物质,如内皮素(Endothelin,简称ET)释放量增加。本研究拟观察降血压肽对脐静脉内皮细胞某些功能的影响,探讨其降血压作用机理,为进一步开发降血压保健食品提供的理论依据。本课题使用的降血压肽是采用酶解法制备而成,经过鉴定,它是一种分子量不到2000的小分子多肽。本研究选择人脐静脉内皮细胞作为实验对象,观察降血压肽对内皮细胞释放ET、NO的影响:观察降血压肽对内皮细胞表达ET、内皮型一氧化氮合酶(eNOS)、诱导型一氧化氮合酶(iNOS)的影响,分别从细胞、分子和基因水平对降血压肽的作用机理进行研究。不同剂量的降血压肽作用于人脐静脉内皮细胞后,进行细胞生长试验及细胞培养液中NO、ET含量的检测。与空白对照组比较,不同剂量的降血压肽可升高培养液中NO含量,降低ET含量;此外去甲肾上腺素的促进脐静脉内皮细胞的生长以及促进脐静脉内皮细胞分泌ET、降低培养液中NO含量的作用可被降血压肽所对抗。这提示降血压肽对血管内皮细胞功能具有保护作用。为了进一步了解降血压肽的作用机制,本实验采用RT-PCR、免疫细胞化学技术研究降血压肽对人脐静脉内皮细胞ET、eNOS、更多还原

【Abstract】 According to many researches,there are active fragments in many protein molecules which have many special physiological functions and can act as some kind of hormone substances in human body.Now,many functional peptides have been acquired from natural protein:Ca-absorption peptides,anti-hypertension peptides, immunity-regulation peptides,et al. Among those, Anti-hypertension peptides are the name of a kind of peptides that can lower the blood pressure of human body. the inhibitor of angiotensin-converting enzyme(ACE), can lower blood pressure by reducing the formation of angiotensin Ⅱ.Vascular endothelial cells(VEC) can secrete many substances that can adjust the blood vessel function and have important relationship with cardiovascular diseases.It is proved by recent researches that VEC disfunction exist as early as in the forepart of hyperpietic disease ; the VEC disfunction can deduce the secretion of NO and induce the secretion of ET. So the objective of this experiment is to explore part mechanism of Anti-hypertension peptides as well as to provide theory support of making and using of this kind of health care food by the means of the influence of Anti-hypertension peptides on the function of VEC.Presently, the research of Anti-hypertension peptides and the relative report in China are rare.The Anti-hypertension peptides used in this experiment is made from corn protein by the means of proteolytic method.It is a kind of small peptides whose molecular weight is smaller than 2000.In the experiment,by investigating the influence of Anti-hypertension peptides on the secretion of ET, NO in VEC and the expression ET,eNOS,iNOS in VEC,to study the influence of Anti-hypertension peptides on the function of VEC and then explore the probable mechanism of Anti-hypertension peptides.Different doses of Anti-hypertension peptides were acted on the vascular endothelial cells and then carry out the growth experiment of cells and measure the amount of NO and ET in the culture media. Campared with the control,the amount of NO in the culture media of different Anti-hypertension peptides groups is higher and the amount of ET islower.Additionaly,the function of noradrenalin that noradrenalin can promote the amount of ET in culture media and reduce the amount of NO can be countermined by the Anti-hypertension peptides. All these indicate that Anti-hypertension peptides have the function of protecting the vascular endothelium cells.In order to study the mechanism of Anti-hypertension peptides deeply,the immunocytochemical staining technique and the semi-quantitative reverse transcription-polymerase chain reaction(RT-PCR) method was used to study the influence of Anti-hypertension peptides on the expression of ETn eNOS^ iNOS in cultured human umbilical vascular endothelial cells and then investigate the antihypertensive mechanism of Anti-hypertension peptides. Anti-hypertension peptides have the function of protecting the vascular endothelium cells. The result revealed that,campared with the control,the expression of ET and iNOS is lower and the expression of eNOS is higer in different Anti-hypertension peptides groups. The result indicate that the antihyertensive function of Anti-hypertension peptides is partly depended on the its effect that it can lessen the expression of ET^ iNOS and induce the expression of eNOS in cultured human umbilical vascular endothelial cells.更多还原