Objective To study the mechanisms and treatment of ischemia /reperfusion injury, expression of intracellular adhesion molecule 1 (ICAM-1) and vascular cell adhesion molecule 1 (VCAM-1) were measured, the effect on suppression of ICAM-1 and VCAM-1 by the pyrrolidine dithiocarbamate (PDTC) were investigated. Methods Endothelial cells were divided into 3 groups, hypoxia group: endothelial cells were exposed in hypoxia condition, then returned to reoxygenation condition; the PDTC group: PDTC was added to the endothelial cells in the culture media before exposing to hypoxia condition; control group: endothelial cells underwent treatment. Confocal microscopy was used to detect expression of ICAM-1 and VCAM-1. Results ICAM-1 and VCAM-1 expression were low in endothelial cells of control group, and increased in hypoxia group . ICAM-1 and VCAM-1 expression of endothelial cells in PDTC group werelower than those in hypoxia group , but higher than those in control group. Conclusions It seems that hypoxia/ reoxygenation can activate the endothelial cells and increase the expression of cell adhesion molecules. PDTC can decrease the expression of ICAM-1 and VCAM-1. PDTC may prove benificial in the treatment of ischemia /reperfusion injury.
ObjectiveTo investigate the expression of tumor necrosis factor α(TNF-α ) in isolated rat heart at different time points after myocardial hypoxia/reoxygenation. MethodsThe isolated langendorff perfused rat heart model was established. Forty-eight SD rats were randomly divided into four groups: a sham group, hypoxia/reoxygenation groups including a H/R 0.5 h group, a 1 h group and a 2 h group. The heart rate(HR), the 1eft ventricular development pressure(LVDP), maximal rates of increase/decrease of the left ventricular pressure(±dp/dtmax) were continuously recorded. The concentrations of TNF-α and creatine kinase-MB(CK-MB) in myocardium, mRNA expression of TNF-α in myocardium were tested. Ultra structure of myocardium was observed under electron microscope. ResultsThe levels of LVDP, ±dp/dtmax, and HR of hypoxia/reoxygenation group were significantly lower than those in the sham group(P<0.05).The levels of TNF-α and CK-MB and the expressions of TNF-α at mRNA level in the hypoxia/reoxygenation group were higher than those in the sham group(P<0.05).There were significant differences in the above parameters among the H/R 0.5 h group, the 1 h group, the 2 h group(P<0.05).The concentrations of TNF-α and CK-MB, the mRNA expression of TNF-α were higher in the I/R 2 h group than those in the other two groups. ConclusionThe high expression of TNF-α in myocardium after myocardial hypoxia/reoxygenation in rats is related to the degree of myocardium damage and may lead to myocardial injury.
Objective To study the protective effects of bone marrow mesenchymal stem cells (BMSCs) of rhesus monkeys on porcine islets from hypoxia/reoxygenation (H/R)-induced injury. Methods BMSCs were isolated and cultured from the marrow of 5 adult rhesus monkeys (weighing, 6-10 kg) by adherent monocytes. Islets were isolated and purified from the pancreas of 5 neonatal porcine (3-5 days old) by collagenase V digestion method, and were cultured with or without BMSCs, and exposed to hypoxia (1%O2) for 12 hours and reoxygenation for 24 or 48 hours, respectively. The experiment was divided into 4 groups: normal islet group (group A), normal islet + BMSCs group (Group B), H/R islet group (group C), and H/R islet + BMSCs group (group D). The survival rate of islets was calculated by fluorescein diacetate/propidium iodide (PI) staining. The viability of the islet cells was detected by cell counting kit 8. Apoptotic rate of islet cells was tested using Annexin V-FITC/PI labeling and flow cytometry. The stimulation index (SI) of islet function was analyzed by glucose-stimulated insulin secretion assay. Results The islet cell cluster of group C was more dispersed than that of groups A and B, and group C had more death cells; and the islet cell cluster of group D was more complete and the survival rate was higher than those of group C. The survival rate of islet was 90.2% ± 9.1%, 88.3% ± 5.9%, 52.3% ± 12.1%, and 71.4% ± 11.5% in groups A, B, C, and D respectively, it was significantly lower in groups C and D than in groups A and B (P lt; 0.05), but it was significantly higher in group D than in group C (P lt; 0.05). After coculture of BMSCs and islet at the ratio of 1 ∶ 10 and 1 ∶ 20 in group D, the viability of islet cells was significantly higher than that in group C (P lt; 0.05). The apoptotic rate was 27.1% ± 3.2%, 24.0% ± 1.0%, 64.3% ± 1.8%, and 46.2% ± 1.4% in groups A, B, C, and D respectively, it was significantly higher in groups C and D than that in groups A and B (P lt; 0.05), but it was significantly lower in group D than in group C (P lt; 0.05). There was no significant difference in SI between groups A and B at each time point (P gt; 0.05), but it was significantly lower in group C than in groups A and B (P lt; 0.05); and it was significantly higher in group D than in group C at 24 and 72 hours (P lt; 0.05). Conclusion BMSCs of rhesus monkeys can protect islet vitality and function from H/R-induced injury.