Age changes of antyoxidant system and free-radical processes in rats at formation of postinfarction cardiosclerosis

Estimation of age dependent changes of the lipid peroxidation (LPO) intensity, content of stable metabolites of nitrogen oxides (NO) and antioxidant enzyme activities in rat blood serum in conditions of experimental postinfarction cardiosclerosis (PICS) is carried out. Initiation of the postinfarction remodeling of animals has been carried out with coronary occlusion, definition of LPO and NO metabolites indices has been performed after 45 days. Investigations have been carried out on 40 four and twelve-month-old male Wistar rats with mass 200-250 gand 400 -450 g, accordingly. Statistical analysis of the results was performed using the Mann-Whitney-Wilcoxone criterion. It has been found that already intact animals have age specificity of indices under consideration. The expressed activity of LPO processes on the background of reduction of endogenous fermentative antioxidant (SOD and catalase) activity as well as nitrite concentration in blood serum is characteristic for PICS of 4-month-old animals. PICS of 12 month-old rats is accompanied with suppression of the LPO processes on the back- ground of reduction of the antioxidant enzyme intensity and increase of NO metabolites production. The following conclusions have been drawn. Process of ontogenesis is characterized by imbalance between pro-and antioxidant processes in rat blood. Increase in catalase activity and concentration of the TBC-active products at simultaneous decrease of SOD activity and content of diene conjugates has been noted. The organism of young animals responds with persistent increase of LPO processes and decrease of SOD and catalase activity on formation of postinfartion cardioslerosis. The less expressed increase of lipid peroxidation activation and decrease of catalase activity has been noted in the organism of old animals within 45 day after PICS formation.

Tissue expression and immunolocalization of cellular repressor of E1A-stimulated gene in postinfarction dysfunctional myocardium

Background Cellular Repressor of E1A-stimu-lated gene(CREG) is widely expressed in adult tissues such as the brain,heart,lung,liver,intestine and kidney in mice.It is not known whether tissue CREG is decreased in the common setting of myocardial infarction which may lead to heart failure.We studied the expression and protein localization of CREG and its main receptor(IFR2R) in a mouse model of myocardial infarction.Methods Male mice were randomized to proximal left anterior descending ligation.The animals were killed on day 1,3,7,14,and 28 after ligation to examine gene expression and protein production of CREG and IGF2R from the infarct,peri-infarct,and contralateral zones of infarcted heart.Results There was decreased CREG mRNA production throughout the myocardium at dav 1,and the expression gradually increased at day 28 after myocardial infarction.The decreased expression of this glycoprotein was not confined strictly to the infarct or peri-infarct zones but also expressed by cardiac myocytes within the myocardium in the contralateral normal zone.Levels of CREG protein in the infarct and peri-infarct zones declined to 1/3- to 1/2-fold of normal levels and declined to 1/2- to 2/3- fold in the contralateral zone.Finally,the expression of the IGF2R mRNA transcripts was downregulated at day 3 and 7 after ligation in the infarct and peri-infarct zones,suggesting that the signal transduction pathways necessary for CREG in the heart remain intact as CREG biosynthesis decreases. Conclusions CREG is constantly present in a model of large myocardial infarction and is decreased at the early stage within the myocardium.The decreased expression of this glycoprotein is not only confined strictly to the infarct or periinfarct zone but also is expressed by cardiac myocytes within the myocardium contralateral to the infarct.Therefore CREG production decreased due to myocardial stress response to injury.

Recruitment of stem cells by hepatocyte growth factor via intracoronary gene transfection in the postinfarction heart failure

We aim to study the amelioration effect of adenovirus5-mediated human hepatocyte growth factor gene transfer on postinfarction heart failure in swine model. Twelve Suzhong young swine were randomly divided into 2 groups of 6 pigs each: Ad5-HGF group and mock-vector Ad5 group. Four weeks after ligation of the left anterior descending coronary artery, Ad5-HGF was intracoronarily transferred into the myocardium. Simultaneously, gate cardiac perfusion imaging was performed to evaluate the heart function. Three weeks later, gate cardiac perfusion imaging was performed again, then the hearts were removed and sectioned for immunohistochemical examination to illustrate the effects of Ad5-HGF on infarcted myocardium. The expression of HGF was examined by ELISA. The results were: (1) compared with the mock-vector Ad5 group, high expression of human HGF was observed in the myocardium of Ad5-HGF group; (2) in the Ad5-HGF group, the number of CD117+ cells co-expressing c-Met per mm2 was significantly larger; (3) the improvement in LVEF was greater in the Ad5-HGF group than in the mock-vector Ad5 group. We concluded that: (1) high expression of human HGF was observed in the myocardium through intracoronary gene transfection; (2) HGF can improve the mobilization of CD117+/c-Met+ stem cells into ischemic myocardium. The amelioration effect of HGF on postinfarction heart failure could not be limited to stimulating angiogenesis, anti-apoptosis, anti-fibrosis, but was also involved in the recruitment of stem cells into myocardium.

Improvement of cardiac function by hepatocyte growth factor via intracoronary transfection in the swine myocardial infarction model

Objective： To study the amelioration effect of AdenovirusS-mediated human hepatocyte growth factor （AdsHGF） on postinfarction heart failure in the swine myocardial infarction model. Methods： Twelve SuZhong young swine were randomly divided into 2 groups with 6 swine in each group： Ad5-HGF-treated group and null-Ad5 group. Four weeks after ligation at left anterior descending coronary artery in swine hearts, Ad5-HGF was transferred to the swine myocardium. Simultaneously, Gated myocardial perfusion imaging was performed to evaluate cardiac perfusion and heart function. After three weeks, Gated myocardial perfusion imaging was performed again, then the hearts were harvested and sectioned to examine the expression of HGF through ELISA. Results： High expression of human HGF was observed in the myocardium of Ad5-HGF-treated group. From 4 weeks to 7 weeks after operation, Left ventricular ejection fraction was increased in Ad5-HGF-treated group. The improvement in LVEF was greater in Ad5-HGF-treated group than that in null-Ad5 group at 7 weeks after operation. Cardiac perfusion was significantly improved in the Ad5-HGF-treated group. Conclusion： High expression of human HGF was observed in the myocardium through intracoronary transfection, which suggests that HGF can ameliorate heart function in swine with postinfarction heart failure.

Possible mechanism of increasing resistance of the myocardium during combination of post infarction remodeling and diabetes mellitus

It was shown that the energy metabolism of the heart mitochondria of experimental animals and patients is more resistant to damage at combined postinfarction cardiosclerosis and diabetes in comparison with the individual pathology. We found that the changes of free fatty acid content and conjugation of the processes of oxidation and phosphorylation in heart mitochondria are components of the metabolic stability of myocardium at the combined development of postinfarction cardiosclerosis and diabetes mellitus. Our data demonstrate a direct link between the violations of the processes of oxidative phosphorylation and accumulation of free fatty acids owing to change in activity of endogenous phospholipases, in particularly, mi- tochondrial phospholipase A2. Similar results were obtained for intraoperative biopsy specimens of patients’ hearts, and of adult Wistar rats’ hearts. We hypothesized that the preservation of energy metabolism is a manifestation of summing up of compensatory processes at de- velopment of nonspecific response of cells to damage at the early stages of pathological pro- cess.