RESUMO
Objective:To analyze the effect of inhibiting excessive mitochondrial fission mediated by dynamic related protein 1 (Drp1) on the function of injured cells and mitochondria in the septic myocardium, and to explore the protective effect of maintaining mitochondrial dynamic balance in the pathogenesis of sepsis induced cardiomyopathy(SIC).Methods:Rat H9C2 cardiomyocytes were cultured and stimulated with lipopolysaccharide (LPS) to establish a model of SIC. Mitochondrial division inhibitor 1 (Mdivi-1) was given 30 min before LPS stimulation. They were divided into the control group, LPS stimulated group (LPS), Mdivi-1 control group (Mdivi-1), and LPS+Mdivi-1 intervention group (LPS+Mdivi-1). CCK-8 was used to detect the cell viability, and lactate dehydrogenase (LDH) was used to detect cellular damage. A MitoTracker probe was used to observe mitochondrial morphology by laser scanning confocal microscopy, JC-1 staining was used to detect mitochondrial membrane potential level, a DCFH-DA probe was used to detect total ROS level, and an AnnexinV-FITC/PI probe was used to detect the cell apoptosis ratio. The expression levels of mitochondrial fission protein Drp1 and fusion proteins Optic Atrophy 1(Opa1) and Mitofusin2 (Mfn2) were detected by real-time PCR and Western blot. One-way ANOVA was used to compare the differences between groups, and the LSD- t test was used for pairwise comparisons between groups. Results:Compared with the control group, cell viability, the average length of mitochondria and the mitochondrial membrane potential were decreased, and ROS production, the cell apoptosis rate and LDH were increased in the LPS group (all P<0.05). After Mdivi-1 intervention, compared with the LPS-stimulated group, the cell viability was increased, myocardial cell damage was reduced, the average length of mitochondria was prolonged, mitochondrial dysfunction was alleviated, and the cell apoptosis rate was inhibited in the LPS+Mdivi-1 group (all P<0.05). Conclusions:Mdivi-1 might inhibit mitochondrial fission mediated by Drp1, maintain mitochondrial dynamic balance, alleviate mitochondrial dysfunction and protect myocardial cells from LPS-induced injury.
RESUMO
Objective In order to understand the quality of drinking water sources and the environment of the Qinghai-Tibet Railway areas. Methods In 2002-2004, the first and second phase of the project of Qinghai-Tibet Railway, 37 sampling sites were chosen in the dry and rainy seasons and the water samples were analyzed according to the national standard test methods. Results In the first phase of the project, the eligible rates of the 39 test indexes of the water sources of 23 sampling sites in the Qinghai-Tibet Railway areas were 82%-95% in the dry season and some decreased in the rainy season. In the second phase, the eligible rates of the test indexes of the water sources of 14 sampling sites were 50%-100% in dry season and in the rainy season, the trend was the same as in the first phase. Conclusion Among the 37 water resources in the Qinghai-Tibet railway areas,the percent of gradeⅠ, gradeⅡ, grade Ⅲ and above grade Ⅲ water source was 67.57%,13.51%,2.70% and 16.22% respectively, some water sources can not be used as the drinking water sources due to the bad quality.