Effects of matrix metalloproteinases on ventricular remodelingfollowing myocardial ischemia in the rat     

ZHANG En-guang  ZHANG Huai-qin  LIN Jie  HUANG Wei-jian  LI Shang-gong  XU Li-xin 《园艺学报》2003,19(5):653-656

AIM:To examine the relationship between the activity of matrix metallproteinases(MMPs) and ventricular remodeling following myocardial ischemia in the rat.METHODS:The model of myocardial ischemia(MI) in the rat was established by isoprenaline(ISP). The activity of MMPs was measured by zymography and collagen concentration was assessed by the method of chloramine T, so did I/III collagen ratio by immunohistochemical staining. The microstructure of myocardium was also observed by electron microscope.RESULTS:The activity of MMP-2 in myocardial ischemia group (group M) increased by 5.8 folds at 1 st week(P＜0.01), 2.3 folds at 2 nd week(P＜0.01) and 1.7 flods at 4 th week(P＜0.05) compared with control group (group C) and MMP-9's activity in group M increased by 4.9 folds (P＜0.01), 1.9 flods(P＜0.01) and 1.4 folds(P＜0.05), respectively. Collagen amount and I/III collagen ratio in group M increased compared with that in group C at 2 nd week and 4 th week. It showed that cardiac myocytes in group M were necrosed and collagen grew abundantly in interstitium under electron microscope.CONCLUSION:The activity of MMPs in the myocardial interstitium increased following myocardial ischemia, then collagen amount and I/III collagen ratio increased, which may be the major causes of ventricular remodeling.  相似文献   

Oxidized low density lipoprotein increases the expression of matrix metalloproteinase-2 in vascular endothelial cells     

HAO Feng  YU Jin-de 《园艺学报》2003,19(6):733-736

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Role of vascular remolding induced by nitric oxide and matrix metalloproteinase in aneurysm     

LIAO Ming-fang  JING Zai-ping  ZHAO Jun 《园艺学报》2004,20(7):1326-1328

Nitric oxide (NO) and matrix metalloproteinases (MMPs) are important in vascular remolding, especially in abdominal aortic aneurysm. NO may be associated with aneurysms by modulating MMPs expression and activity.  相似文献   

自卸车举升机构矩阵变换算法统一格式的研究   总被引：1，自引：1，他引：1  

张毅  马力  王元良  满开美  李鹏飞 《拖拉机与农用运输车》2005,(1):21-23

针对自卸车各种举升机构提出了矩阵变换算法的统一格式,推导出统一格式下各举升机构的变换矩阵,并开发了通用设计系统。该系统可计算任一举升时刻举升机构各铰接点位置和油缸推力。  相似文献   

Demography,population dynamics and sustainability of the Patagonian sheep flocks     

Marcos Texeira  Jose M. Paruelo 《Agricultural Systems》2006

Sheep production is the main agricultural activity in Patagonia. Since the middle of the 20th century, sheep numbers have declined steadly. We used historical records of stock numbers in four ranches to analyze the importance of regional factors so as to explain the decline of the Patagonian sheep flocks. We found that the stocks of all the four ranches declined with a similar trend but fluctuated independently, thus reflecting a complex interaction between regional and local factors. Aboveground net primary production (ANPP) and vegetation physiognomy explained most of the differences in the flocks declining rates. We estimated demographic parameters for two ranches differing in their average annual growth rates. From these demographic parameters, we constructed deterministic and stochastic matrix models to establish the relative contribution of demographic processes to the observed decline. Matrix models projected a faster decline than that observed in the ranch used to calibrate the model. This suggests that the recorded demographic parameters could drive most stocks to extinction in less than 100 years. We concluded that the observed dynamics would be generated by demographic processes, but extinction is delayed or avoided by a continuous intake of animals. Ewe survival was the most important parameter in controlling the growth rate of the flocks. The environmental stochastic model showed that the growth of the stocks was highly sensitive to increases in the frequency of good years (those that produce a positive growth) and in the transition from normal years to bad years. All these evidences point out the existence of biological constraints to sheep production in Patagonia: ANPP and vegetation structure would control flock population dynamics throughout its effects on key demographic parameters, ewe survival and marking rate (a recruitment measure). Our model results suggest that the decline in sheep numbers, and hence the sustainability of the activity, is driven, to a large extent, by the demographic characteristics of the flocks.  相似文献   

重庆地区水稻土胶膜及基质的研究     

WANGLin-xue  YANGYi  YANGJian-hong 《土壤通报》2008,(6)

对重庆地区水稻土胶膜及基质土壤中某些元素含量情况及相互之间的关系进行了研究。结果表明:胶膜的pH值、有机质含量均明显高于基质土壤,且有机质含量差异极显著(P<0.01);胶膜中全氮、全磷含量高于其基质土壤且差异均达到极显著水平(P<0.01),全钾在胶膜与基质土壤中含量无明显变化,胶膜中铜、锌含量总体上高于其基质土壤,二者间锌含量差异达到显著水平(P<0.05);供试胶膜中全铁含量极显著高于基质土壤(P<0.01),全锰含量无一致性规律,胶膜中全锰含量总体上较基质土壤高,但二者差异不显著(P>0.05);供试胶膜中全磷与全铁含量显著相关(r=0.606*,n=12),具有较好的伴生关系,胶膜中铜与铁、锰含量均极显著相关(r铜铁=0.792**,r铜锰=0.737**;n=12),但铜与锰伴生关系较好,而锌与铁的伴生关系较好。  相似文献   

Effects of swimming on experimental endometriosis in rats     

JING Yan-lin  YANG Xiu-zhao  BAI Zhen-jun  HE Qian-li 《园艺学报》2000,36(10):1892-1896

AIM To evaluate the effect of swimming on experimental endometriosis in rats. METHODS 80 female SD rats were divided into 8 groups, including control group, model group and animals performed light exercise （swimming once a week）, moderate exercise （swimming 3 times a week）, and intense exercise （swimming 5 times a week） before or after endometriosis induction,10 rats in each group. The mRNA and protein expressions of fatty acid synthase （FAS）, matrix metalloproteinase 9 （MMP9） and proliferating cell nuclear antigen （PCNA） in endometrium of rats were detected. RESULTS The swimming before the induction of the edometriosis lesions did not prove to have aprophylactic role against endometriosis, whereas the swimming after induction of the lesions had a beneficial effect regardless of frequency, with a greater reduction in the groups practicing moderate and intense activity （P<0.05）, an increase in FAS levels and a decrease in MMP9 and PCNA levels were also observed （P<0.05）. CONCLUSION Swimming after induction of the edometriosis is beneficial for the treatment of endometriosis, the mechanism may be related to the expression of FAS, MMP9 and PCNA protein.  相似文献   

Down-regulated TCF3 expression inhibits growth and migratory abilities of non-small cell lung cancer cells     

WANG Shi-meng 《园艺学报》2017,33(2):289-296

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All-trans retinoic acid attenuates blood-brain barrier injury induced by cerebral ischemia-reperfusion in rats through JNK/P38 MAPK signaling pathway     

LI Ming-hang  TIAN Xiao-cui  AN Rui-di  ZHANG Qian  YANG Mei  XIANG Fei  WANG Yu-chun  XU Lu  DONG Zhi 《园艺学报》2019,35(1):112-118

AIM: To investigate the effect of all-trans retinoic acid (ATRA) on blood-brain barrier after cerebral ischemia-reperfusion (CIR) injury in rats and its possible role mechanism.METHODS: Male SD rats were randomly divided into sham group, model (CIR) group and CIR+ATRA (10, 30 and 90 mg/kg) groups. The rat model of CIR injury was established by MCAO thread occlusion method. After ischemia for 1.5 h and reperfusion for 24 h, the neurological functional behavioral score, cerebral infarction volume, brain water content and Evans blue content were determined. The activity of matrix metalloprotein-9 (MMP-9) was measured by gelatin zymography. The protein levels of claudin-5, occludin, ZO-1, JNK, p-JNK, P38, p-P38 and MMP-9 in the brain tissues were determined by Western blot.RESULTS: Compared with CIR model group, ATRA at 30 mg/kg significantly improved neurological function, and decreased cerebral infarction volume, brain water content, Evans blue content and the degradation of tight junction proteins in ischemic area (P<0.01). The activity and protein expression of MMP-9 in ischemic brain tissue were decreased (P<0.01). The phosphorylation of JNK and P38 was inhibited and the protein levels of p-JNK and p-P38 were decreased (P<0.01).CONCLUSION: ATRA reduces the damage of brain tissue and the destruction of blood-brain barrier induced by CIR in rats. The protective effect may be related to inhibiting the activation of JNK/P38 MAPK signaling pathway and MMP-9.  相似文献   

不同基质对红颊草莓生长发育及果实品质的影响     

孟令春  李曼  渠慎春 《中国果业信息》2015,44(6)

本研究以红颊草莓为试验材料,在温室立体阶梯式高架栽培模式下,通过对比国外专用基质和国内基质对“红颊”草莓的生长和果实品质的影响,从而筛选出适合“红颊”草莓的基质。结果表明上层国外专用基质红颊草莓在营养生长阶段比国内基质上层生长健壮;中层和下层国外专用基质和自己配制基质处理对草莓营养生长发育没有显著性差异;果实品质方面无论是上层、中层或下层,国外专用基质和国内基质处理也没有显著性差异。同一基质上、中、下三层之间果实品质也没有差异。综合这两种基质对草莓植株生长和果实品质等指标的影响,两种基质对草莓的生长发育差异不显著,国内基质完全可以代替国外专用基质使用。  相似文献