Experimental Study On Traditional Chinese Medicine Of Tonifying Qi And Activating Blood Delaying The Reaction Of Nonenzymatic Glycosylation Of Senescent Rats

To future explore the effects of nonenzymatic glycosylation in the process of aging, we built the senescent rats as model, and tested the content of AGEs in thoracic aorta, heart and kidney, and discuss the relationship between other indexes of organic aging. We also give traditional Chinese medicine of tonifying Qi and activating blood to rats, discuss the mechanism of TCM in inhibiting the reaction of nonenzymatic glycosylation and delaying organic senesence.This study can be devived into two parts, including literature review and basic research.1. Literature reviewBasing on the theory of aging: nonenzymatic glycosylation,we reviewed the articles about how the reaction of nonenzymatic glycosylation makes effect on blood vessels, causing vascular injury both under physiological and pathological conditions. These works confirm that the process of nonenzymatic glycosylation becomes more serious with increase of age, which can damage blood vessels through many complicated ways and lead to vascular age related changes in range of form and function. This article tries to discuss the relationship between nonenzymatic glycosylation and vascular aging, aiming to provide the theoretical basis for future research of delaying vascular aging.2. Basic research:This part includes two basic experiments.Experiment I:Experimental Study on Traditional Chinese Medicine of Tonifying Qi and Activating Blood Delaying the Reaction of Nonenzymatic Glycosylation of Senescent Rat.Objects:To explore the structural and functional changes of important organs like thoracic aorta, heart and kidney in senescent rat, emphasize the import role of the reaction of nonenzymatic glycosylation, and discuss the therapeutic effect of traditional Chinese medicine(extacts from Radix Ginsen, Radix Notoginseng and Rhizoma Chanxiong).Methods: To build the models of natural aging, they were all divided into five groups including aging-model group, Chinese medicine high-dose group, medium-dose group, low-dose group, and Losartan control group, except for that, build a youth control group. After15-week intervention the following indexes were observed with corresponding methods:morphological changes of thoracic aorta, heart and kidney by HE, morphological changes of collagen fibers in thoracic aorta by picrosirius red stainings, the content of AGEs of different organs with enzyme linked immunosorbent assay (E1ISA) and immunohistochemistry (IHC), the content of Ang II of different organs by radio immunoassay and IHC, the content of TGF-P of kidney by IHC, the content of MDA of heart with thiobarbituric acid(TBA), and the content of creatinine (Cr) by biochemical techniques.Results:Compared with young group, the aging models showed characterstics as following: in thoracic aorta tissue, increasd thickness of vascular wall, migration of smooth muscle cells, abnormality of collagen, fragmentation and thinning of elastic lamellae, increased content of AGEs and Ang II. In heart tissue, decreased number of myocardial cells, hypertophy and irregular arrangement of myocardial cells, increased content of AGEs, Ang II and MDA. In kidney tissue, decreased number of glomerulus, hyperplasia of mesangial, atrophy of renal tubular, interstitial fibrosis, increased content of AGEs, Ang II and TGF-βin kidney and increased content of Cr in serum. The traditional medicine could decrease the content of AGEs, Ang II, MDA, TGF-βand Cr in different tissues, improve the characters of structure and function of organs. The correlation analysis turns out that there are positive correlation relationship between the content of AGEs and MDA in heart tissue, AGEs and TGF-β in kidney tissue, AGEs and Ang II in heart, kidney and thoracic aorta tissue, AGEs in thoracic aorta and AGEs in heart, AGEs in thoracic aorta and AGEs in kidney, Ang II in thoracic aorta and Ang II in heart, Ang II in thoracic aorta and Ang II in kidney.Conclusion:1.The reaction of nonenzymatic glycosylation is increased with age, the content of AGEs accumulate in thoracic aorta, heart and kidney. Increased AGEs could induce the reaction of oxidative stress and frbrosis.2. The content of AGEs and Ang II are increased with age in thoracic aorta, heart and kidney, and there are positive correlation relationship between AGEs and Ang II, Losartan could decrease the content of AGEs and Ang II, it illustrate that the activation of RAS with age may induce the process of nonenzymatic glycosylation, finally leading to senescence of organs.3. Chinese medicine may have the function like Losartan, it can inhibit the activation of RAS system, delay nonenzymatic glycosylation reaction, thus future delay oxidative stress, fibrosis progress, to the purpose of delaying senescence of organs.4. There are close relationship between vascular aging and organic aging, vascular aging may induce organic aging through blood pressure, endocrine system, and nutrient substance exchange regulation.Experiment II:Application of Abrio imaging system in observing the structure of fibers in thoracic aorta of rats.Objects: In this study, we chose the thoracic aorta of rats to explore the imaging features and application fields of Abrio imaging system.Methods: It is the first time of using Abrio imaging system to observe the structure of fibers in thoracic aorta of yuang and old rats without dyeing. Then we stained the collagen fibers in aortic alices with picric-sirius red to compared the difference between Abrio and traditional polarized imaging techniques.Results: Abrio imaging system clearly displayed the structure of fibers in thoracic aorta of rats without dyeing. Comparing with young rats, the birefringence of fibers in aortic adventitia of old rats are stronger while the birefringence of fibers in media being weaker and the structure of elastic membrane becoming unclear. To quantify the azimuth of birefringence signals of fibers,we got the result that the variability of azimuth was greater in thoracic aorta of old rats than that of young rats (P<0.01), this result consistented with the physiological and pathological changes of vascular aging. After picric-sirius red staining, Abrio could got the images without the limitations of fiber orientation and artificial factors, the results are more complete and objective compared to the traditional polarized light technology. The retardance of of collagen fibers was greater in thoracic aorta of old rats than young rats (P<0.01)Conclusion: Abrio imaging system can be used to analyze the magnitude and orientation of a sample’s birefringence qualitatively and quantitatively, it can reveal the microstuctructure without dyeing and get images independent of the sample orientation, but it can not distinguish between type I and type III collagen.