【Abstract】Objective To observe the synthesis of TLR2 protein and its mRNA expression in Kupffer cells (KCs) and sinusoidal endothelial cells(SECs).Methods Thirty-two BALB/c mice divided into two groups (operation group and false operation group) were used to prepare the model of partial hepatic ischemia/reperfusion (I/R) injury. After injury KCs and SECs were isolated with twosteps situ perfusion technique. And these cells were dyed by rat anti-mouse TLR2 IgG and anti-rat IgG2b labeled with flurescein isothiocyanate (FITC). The sysnthesis of TLR2 protein were determined by flow cytometric (FCM) analysis and real time reverse transcription polymerase chain reaction (Real-Time RT-PCR) analysis for gene expression.Results As for KCs: TLR2 expression was significant higher in operation group, compared with false operation group 〔protein expression: （9.19±1.07）% vs （1.52±0.21）%, P＜0.01; gene expression: 0.54±0.77 vs 2.62±2.19, P＜0.05〕. But there were no significant differences with expression in SECs. Conclusion Synthesis of TLR2 protein and its gene expression increased in KCs in the mouse partial hepatic ischemia-reperfusion injury.
OBJECTIVE: To investigate the injury on isolated testes induced by ischemia/reperfusion(I/R), and the protective effect of Yisheng injection on the injury. METHODS: Twenty-six isolated cadaver testes contributed by 13 persons were preserved with 4 degrees C 250 ml hypertonic citrate alloxuric (HCA) solution and then reperfused with 37 degrees C 500 ml HCA. Solution of experimental group contained 500 micrograms/ml Yisheng injection. In simple cold preservation test, involving in 8 experimental and 8 control testes, a series of time points (6, 12, 18, 24, 36, 48, 60, 72 hours) were set to harvest. 10 testes (1 testis respectively on 6, 12, 18, 24 and 36 hours in experimental and control groups) were reperfused with 37 degrees C HCA for 6 and 12 hours. Histological and histochemical changes were observed. RESULTS: In the experimental testes, 4 degrees C cold preservation in 24 hours could not induce obvious pathologic changes. After 24 hours, changes such as swelling, vacuolar degeneration or detachment of endothelial cells (ECs), separation between basement membrane and seminiferous epithelium, mal-alignment of spermatogenous cell and edema of mesenchyme could be observed. In the testes preserved for 12 hours, the activity of lactic dehydrogenase(LDH) and succinic dehydrogenase (SDH) increased, then fallen after 24 hours. The activity of Nitric oxide synthetase(NOS) decreased after 18 hours. All changes were more obvious after following 37 degrees C reperfusion. In the control testes, swelling and vacuolar degeneration of ECs occurred on 12 hours cold preservation, and injury was worse along with the prolongation of cold preservation time. Pathologic changes of ECs, seminiferous epithelium and mesenchyme were serious after 37 degrees C reperfusion. CONCLUSION: 4 degrees C cold preservation in 24 hours can only cause mild ECs’ injury, and obvious abnormal testes’ histological profile can be observed beyond 24 hours. 37 degrees C reperfusion will make injury worse. Yisheng injection can keep isolated testes histologic structure well in 24 hours cold preservation, and it has protective effect on I/R injury.
ObjectiveTo summarize recent researches on mechanism of the hepatic ischemic preconditioning (IPC) and its clinical applications on hepatectomy and liver transplantation. MethodsRelevant references about basic and clinical researches of hepatic IPC were collected and reviewed. ResultsRecent experimental researches indicated that IPC could relieve hepatic ischemiareperfusion injury (IRI) by remaining and improving energy metabolism of liver, regulating microcirculation disorder, decreasing the production of lipid peroxidation and oxyradical. It could also inhibit the activation of inflammatory cells and the release of cytokine, suppress cell apoptosis and induce the release of endogenous protective substance. Till now, most of the clinical researches had confirmed the protective function of hepatic IPC, but there were still some references with opposite opinions. ConclusionHepatic IPC could relieve liver IRI, but its clinical application value on hepatectomy and liver transplantation still need more researches to prove.
Objective To study the effect of dexamethasone to protect flaps from an ischemia-reperfusion injury and elucidate its mechanism of regulating the death course of the neutrophils.Methods The rats were randomly divided into 3 groups.The vein of the rat was clamped for 8 h after the flap had formed. Group A: the normal flap; Group B: the saline control flap; Group C: the treatment flap with dexamethasone. The survival area of the flaps was measured at 7 days; the apoptotic and necrotic neutrophils,tumor necrosis factor α （TNF-α）, and interleukin 10 （IL-10） concentrations were measured. Results The flap survival areas in Groups A and C were larger than those in Group B. The apoptotic neutrophils in Group B were fewer than those in Groups A and C on the 1st and 3rd days after operation; however, they were more in number in Group B than in groups A andC on the 6th day. The necrotic cells in Group B were more in number than those in Groups A and C. In Group B, the plasma TNF-α concentration reached the maximum level at 1 h,while the IL-10 level reached the lowest 3 h after the reperfusion. In Group C, the TNF-α concentration was lower than that in Group B and decreased dramatically at 6 h. The IL-10 concentration was the lowest at 1 h, and increased rapidly at 3 h. Thus, ischemia reperfusion could injure the flaps, probably through the abnormal action of the neutrophils, such as the disordered secretion of the cytokines and abnormal death course of the neutrophils. Conclusion Dexamethasone can protect the flap from an ischemia-reperfusion injury by its regulation for the neutrophil function.
Objective To summarize recent research advancement on gene therapy for hepatic ischemia-reperfusion injury (IRI). Methods Relevant references about basic and clinical researches of hepatic IRI were collected and reviewed. Results Recent experimental researches indicated that the expression of several genes and cytokines could protect hepatic cells by suppressing cell apoptosis, decreasing the production of oxyradical, remaining and improving portal venous flow, promoting bilifaction, self immunoloregulation and decreasing inflammatory reaction, so that it could decrease IRI. Conclusion IRI could be decreased by regulating the expressing of target genes or transducing relative genes in vivo, but the path of gene transfer and the selection and optimization of gene carrier still need more basic and clinical researches to prove.
Objective To explore the impact of ischemic postconditioning on ischemia-reperfusion injury in isolatedelderly rat hearts and their relation with P-Akt. Methods A total of 30 healthy elderly SD rats (21-23 months old， male or female) with their body weight of 450-500 g were divided into 3 groups: control group， ischemia-reperfusion group， and postconditioning group， with 10 rats in each group. Coronary artery blood flow，myocardial infarction size， phosphorylatedAkt （p-Akt） expression， and changes in myocardium and mitochondria were detected. Results Coronary artery blood flow of the postconditioning group was significantly higher than that of the ischemia-reperfusion group （6.4±1.2 ml/min vs.3.1±1.2 ml/min， P＜0. 01）， and myocardial infarction size of the postconditioning group was significantly smaller thanthat of the ischemia-reperfusion group （35.0%±2.0% vs. 55.7%±3.6%， Plt;0. 05）. The expression of P-Akt was significantlyhigher， and myocardial fibers and mitochondria were preserved better in the postconditioning group than the ischemia-reperfusion group. Conclusion Ischemic postconditioning can protect isolated elderly rat hearts against ischemia-reperfusion injury， which may be related to P-Akt activation.
Objective To observe the influences of depolarized arrest and hyperpolarized arrest on alternation of fluidity of myocardial cell membrane during cardiopulmonary bypass (CPB) and evaluate the protective effects on myocardium of hyperpolarized arrest. Methods Seventy-two felines were randomized into three groups, each group 24. Control group: 180 minutes of CPB was conducted without aortic and vena caval cross-clamping. Depolarized arrest group: hearts underwent 60 minutes of global ischemia after aortic cross-clamping (ACC) followed by 90 minutes of reperfusion. The cardioplegic solution consisted of St. Thomas solution (K+16mmol/L). Hyperpolarized arrest group: the protocol was the same as that in depolarized arrest group except that the cardioplegic solution consisted of St.Thomas solution with pinacidil (50 mmol/L,K+5mmol/L). Microviscosity, the reciprocal of fluidity of myocardial membrane was measured in all groups by using fluorescence polarization technique. (Results )Microvis cosity of myocardial cell in depolarized arrest group during ACC period was significantly higher than that before ACC and kept on rising during reperfusion period. Microviscosity of myocardial cell in hyperpolarized arrest group during ACC was trending up and reperfusion periods as well, but markedly lower compared to that in depolarized arrest group at corresponding time points(Plt;0.01). Conclusion Hyperpolarized arrest is more effective in protecting myocardial cells from ischemia-reperfusion injury than depolarized arrest during CPB by maintaining better fluidity of myocardial membrane.
To investigate the effect of propofol intra-aortic and intravenous infusion on the concentration of propofol for an ischemia-reperfusion spinal cord injury in rabbits. Methods Forty-six healthy adult New Zealand white rabbits were randomly divided into 3 groups: sal ine infusion group (group N, n=10), propofol intra-aortic infusion group (group A, n=16) and propofol intravenous infusion group (group V, n=16). The infrarenal abdominal aorta was occluded for 30 min during which propofol 50 mg/kg was infused continuously intra-aortic or intravenous with a pump in group A and V. In group N, the same volume of normal sal ine was infused in the same way and at the same rate as in group A. Upon reperfusion, propofol concentration of the spinal segments of L4-6 and T6-8 was examined in group A and V. At 48 hoursafter reperfusion, the neurological outcomes were recorded in each group. Results Mean blood pressure in group V from the time of 5 minutes after occlusion decreased more than in group N (P lt; 0.05) and than in group A from the time of 10 minutes after occlusion(P lt; 0.05). The mean blood pressure in group N increased more than in group A from 15 minutes after occlusion (P lt; 0.05). The heart rate increased more in group V from 10 minutes after occlusion than in group N and A (P lt; 0.05) in which no difference was observed. The propofol concentration in L4-6 of group A (26 950.5 ± 30 242.3) ng/g was higher than that in T6-8 of group A (3 587.4 ± 2 479.3) ng/g and both L4-6 (3 045.9 ± 2 252.9) ng/g and T6-8 (3 181.1 ± 1 720.9) ng/g of group V(P lt; 0.05). The paraplegia incidence was lower (30%) and the median of normal neurons was higher (8.4) in group A than in group N (80%, 2.2) and group V(100%, 1.9), (P lt; 0.05). There was no significant difference in group N and V in paraplegia incidenceand the median of normal neurons (P gt; 0.05). Conclusion Intra-aortic infusion shows a better neurological outcome than intravenous infusion and could contribute to higher concentration of propofol in the ischemia spinal cord.
Adenosine triphophate (ATP), substantially liberated from the injured cells, activates the inflammatory cells to secrete various inflammatory factors, thus triggering uncontrolled systemic inflammatory response and thrombosis with aggravating the degree of damage. Metabolic pathway of adenosine consists of adenosine (Ado) synthase CD39-CD73, nucleoside transporters (NTs) and termination system of adenosine deaminase (ADA) and adenosine kinase (ADK). As a " switch” of the inflammatory response, the metabolic pathway converts ATP (the pro-inflammatory cytokines) to Ado (the anti-inflammatory mediators), maintaining the homeostasis between pro-inflammatory and anti-inflammatory as well as affecting the outcome of the injury. This review focused on the recent progress of adenosine metabolic pathway in cell injury.
【Abstract】 Objective To investigate the effect of verapamil on apoptosis, calcium and expressions of bcl-2 and c-myc of pancreatic cells in ischemia-reperfusion rat model. Methods Wistar rats were randomly divided into three groups: control group （n=10）; ischemia-reperfusion group （n=10）; verapamil treatment group （n=10）. The anterior mesenteric artery and the celiac artery of rats in both ischemia-reperfusion group and verapamil treatment group were occluded for 15 min followed by 12-hour reperfusion. Verapamil （1 mg／kg） was injected via caudal vein to the rats in verapamil treatment group 15 min before occlusion and 1 hour after the initiation of reperfusion, respectively; and ischemia-reperfusion group was given the same volume of salient twice intravenously. Pancreatic tissues were collected from the dead rats after twelve hours since the reperfusion. The pathologic characters of pancreatic tissue were observed under light microscope; The level of calcium in the tissue was measured by atomic absorption spectrometer; TUNEL was used to detect apoptosis of pancreatic cells; and the expressions of c-myc and bcl-2 in the cells were also analyzed by immunohistochemistry technique and flow cytometry. Results The pathologic change in verapamil treatment group was less conspicuous than that of ischemia-reperfusion group. Both the calcium level and the number of apoptotic cells in verapamil treatment group were less than those of ischemia-reperfusion group 〔（411.1±55.8） μg/g dry weight vs （470.9±31.9） μg/g dry weight, P＜0.05 and （9.5±2.9）% vs （18.4±3.1）% 〕, P＜0.05. After taking verapamil, the number of apoptotic cells decreased, whereas the expressions of bcl-2 and c-myc increased. The fluorescent indexes of bcl-2 and c-myc in verapamil treatment group were significantly higher than those of ischemia-reperfusion group (1.72±0.11 vs 1.41±0.07, P＜0.05; 1.76±0.19 vs 1.55±0.13, P＜0.05. Conclusion Ischemia-reperfusion injury can induce apoptosis of pancreatic cells. Verapamil could protect the injured pancreatic tissue by reducing the level of calcium, stimulating the expressions of bcl-2 and c-myc and inhibiting apoptosis of pancreatic cells.