The protective effects of cyclosporin A on vascular permeability in sepsis rats / 药学学报

The protective effects of cyclosporin A (CsA), an inhibitor of mitochondrial permeability transition pore (MPTP), on vascular permeability in sepsis rats were investigated. Cecal ligation and puncture (CLP)-induced sepsis rats were used for in vivo studies, and the effects of CsA (1 and 5 mg·kg-1) on vascular permeability of lung, kidney, and intestine, mitochondrial respiratory control ratio, and the survival of the sepsis rats were observed. Lipopolysaccharide (LPS) was used for stimulating vascular endothelial cells (VECs) in vitro, and the effects of CsA on leakage of microvascular, immunofluorescence of zonula occludes-1 (ZO-1), and transendothelial electrical resistance (TER) were observed. All the animal welfare and experimental procedures are in accordance with the regulations of the Animal Ethics Committee of the Army Medical University. Compared with sham-operated group, the vascular permeability of lung, kidney, and intestine in sepsis rats increased significantly (P<0.05). Compared with conventional treatment group, CsA could significantly decrease the vascular permeability of lung, kidney, and intestine (P<0.05 or P<0.01), and prolong the survival period. The results of microcirculation also showed that CsA could significantly reduce the permeability of mesenteric venules in sepsis rats. At the cellular level, LPS stimulation significantly increased the permeability of vascular endothelial cells, including the decrease of transmembrane resistance and protein expression of ZO-1 (P<0.05). CsA can significantly reduce the increase of permeability of vascular endothelial cells induced by LPS stimulation (P<0.01). The function of mitochondria in the kidneys and intestines of sepsis rats was obviously impaired, and the respiratory control ratio of mitochondria was decreased. LPS significantly increased MPTP opening of VECs, while CsA significantly inhibited MPTP opening and improved mitochondrial function. CsA may protect mitochondrial function by inhibiting the opening of MPTP and play a protective role in the vascular permeability of sepsis rats. This study will provide an insight for the treatment of sepsis vascular leakage.

Two-dimensional gel electrophoresis of subcellular fractions of hepatoma cells / 中华肝脏病杂志

<p><b>OBJECTIVES</b>To seek a better profiling of proteins of hepatoma cells.</p><p><b>METHODS</b>The homogenate of hepatoma cells QGY-7703 was fractionated into four parts by differential centrifugation: the nuclei, the pellet by 20,000 x g, the pellet by 100,000 x g and the cytosolic supernatant. The four fractions were submitted to two-dimensional gel electrophoresis and their electrophoretic patterns were analyzed.</p><p><b>RESULTS</b>In comparison with the protein pattern of hepatoma cells not fractionated, the patterns of the four fractions display many more protein spots, and a large number of proteins present in the nuclei and cytosolic supernatant were not shown in the not-fractionated samples.</p><p><b>CONCLUSION</b>Preparation of subcellular fractions before electrophoretic procedures proves to be very useful; not only can it improve the results of two-dimensional gel electrophoresis, but also can lead to research into the subcellular level.</p>

PMN apoptosis and its relationship with the lung injury after chest impact trauma / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Polymorphonuclear neutrophil (PMN), one of the most important inflammatory cells, functions throughout the initiation, progression and resolution of inflammation. This study aimed at investigating the relationship between PMN apoptosis and the lung injury after chest impact trauma.</p><p><b>METHODS</b>PMNs were purified from rabbits subjected to the chest impact trauma and their apoptosis, necrosis, survival and respiratory burst were detected by flow cytometry. Meanwhile, lactate dehydrogenase and (LDH) [Ca2+]i were measured.</p><p><b>RESULTS</b>The delayed apoptosis of PMNs in bronchoalveolar lavage fluid was observed from 2 hours to 12 hours after trauma, and viable cells increased. Respiratory burst of PMNs in bronchoalveolar lavage fluid was increased significantly from 2 hours with the peak at 8 hours. Meanwhile, lactate dehydrogenase in bronchoalveolar lavage fluid was higher than that in control (P < 0.05) from 4 hours to 24 hours, and intracellular free Ca2+ in PMN was increased temporarily.</p><p><b>CONCLUSIONS</b>Retention of PMN in tissues and the abnormality in apoptotic pathway inevitably generate persistent activation of PMN and excessive release of toxic substances, resulting in tissue injury. The temporary increase of intracellular free Ca2+ may be responsible for the delayed apoptosis of PMN.</p>

Death style and respiratory burst of neutrophils in peripheral blood and pulmonary alveolus under endotoxemia in rats / 中国实验血液学杂志

To study the difference of changes on apoptosis, necrosis and respiratory burst of the polymorphonuclear neutrophils (PMN) in endotoxemia rat model. LPS (O(55)B(5), 5 mg/kg) was injected into abdominal cavity of 20 random normal Wistar rat. 2, 4, 8 and 12 hours after injection, the changes of apoptosis, necrosis and respiratory burst of the rats between PMN from the peripheral blood and from the bronchoalveolar lavage fluid were observed using the flow cytometer. At the same time, 5 uninjected rats were taken as control. The results demonstrated that the quantity proportions of apoptosis of PMN between the peripheral blood PMN and the bronchoalveolar lavage fluid PMN in rat's endotoxemia were similar. However, comparison with the uninjected LPS rat, the necrosis of peripheral blood PMN obviously increased and the respiratory burst capacity was clearly inhibited. Contrarily, the necrosis of bronchoalveolar lavage fluid PMN obviously decreased and the respiratory burst obviously increased in the injecting LPS rat. It was concluded that the necrosis and apoptosis displayed differently between the pulmonary and peripheral blood PMNs in endotoxemia. Under state of inflammation, the surviving PMN in tissue increased and kept the activated state due to tissue injury.

Therapeutic and preventive effect of dexamethasone on endotoxin shock in rabbits and its relationship with TNF / 第三军医大学学报

Objective　To explore the effect of dexamethasone (Dex) given with the intention of prevention or treatment on endotoxin shock in rabbits and its relationship with tumor necrosis factor (TNF). Methods　Fifty-three health rabbits were divided into 4 groups, including normal control (n=13), endoxin shock group (n=16), preventive Dex group (n=12) and therapeutic Dex group (n=12). Except normal control was given with saline, the other 3 groups were administered with lipopolysaccharide (LPS) infusion, and the preventive Dex group was treated with Dex (5 mg/kg body weight) 30 min before LPS infusion and the therapeutic Dex group 20 min after LPS infusion. Mean arterial blood pressure (MABP), survival rate, TNF level in circulatory blood and other parameters were detected. Results　In preventive and therapeutic Dex groups, MABP was increased and survival rate was reduced compared with the animals from endoxin shock group (P<0.05, P<0.01), and TNF activity in the circulating blood was significantly suppressed (P<0.01). In addition, dexamethasone administration could alleviate the elevation of plasma glucagon, glucose, lactic acid, and β-glucironidase (P<0.05, P<0.01) in shocked animals. It was also found that administration of dexamethasone in vitro prevented the release of TNF by Kupffer cells. Conclusion　These results indicate that the preventive and therapeutic effect of dexamethasone on endotoxin shock, which may relate to its direct inhibition of the release of TNF induced by LPS.

Therapeutic and preventive effect of dexamethasone on endotoxin shock in rabbits and its relationship with TNF / 第三军医大学学报

Objective　To explore the effect of dexamethasone (Dex) given with the intention of prevention or treatment on endotoxin shock in rabbits and its relationship with tumor necrosis factor (TNF). Methods　Fifty-three health rabbits were divided into 4 groups, including normal control (n=13), endoxin shock group (n=16), preventive Dex group (n=12) and therapeutic Dex group (n=12). Except normal control was given with saline, the other 3 groups were administered with lipopolysaccharide (LPS) infusion, and the preventive Dex group was treated with Dex (5 mg/kg body weight) 30 min before LPS infusion and the therapeutic Dex group 20 min after LPS infusion. Mean arterial blood pressure (MABP), survival rate, TNF level in circulatory blood and other parameters were detected. Results　In preventive and therapeutic Dex groups, MABP was increased and survival rate was reduced compared with the animals from endoxin shock group (P<0.05, P<0.01), and TNF activity in the circulating blood was significantly suppressed (P<0.01). In addition, dexamethasone administration could alleviate the elevation of plasma glucagon, glucose, lactic acid, and β-glucironidase (P<0.05, P<0.01) in shocked animals. It was also found that administration of dexamethasone in vitro prevented the release of TNF by Kupffer cells. Conclusion　These results indicate that the preventive and therapeutic effect of dexamethasone on endotoxin shock, which may relate to its direct inhibition of the release of TNF induced by LPS.