Objective To investigate the effect of advanced glycation end products (AGEs) on the catalase activity and the levels of malondialdehyde in cultured bovine retinal capillary pericytes (BRPs), and to investigate the relationship between oxidative stress and diabetic retinopathy. Methods Cultured BRPs were exposed to AGEs (0, 8, 32, 125, 500, 2 000 μg/ml) for four days. Activity and the levels of catalase and malondialdehyde in cultured BRPs were examined by spectrophotometry. Results AGEs decreased the catalase activity, whereas increased the levels of malondialdehyde of cultured BRPs in a dose-dependent manner (r=-0.714, r=0.748, P＜0.01).There were significant differences between BRPs cultured in 32 μg/ml AGEs and in control group (P＜0.01), while no significant differences between BRPs cultured in non-glycated bovine serum albumin and absence of bovine serum albumin were found. Conclusion Oxidative stress may be one of the reasons why the pericyte disappears in diabetic retinopathy. (Chin J Ocul Fundus Dis, 2002, 18: 143-145)
Through dog models of common bile duct obstruction (BDO), the contents of liver superoxide dismutase (SOD) and malondialdehyde(MDA) were measured 2,3,4 and 5 weeks after BDO. Results indicated that the hepatic MDA content was increased 2 weeks after BDO as compared with control group (Ｐ＜0.01), the hepatic SOD content was decreased 3 weeks after BDO (Ｐ＜0.05). When bile duct obstructing, these changed were more serious. The results suggest that liver has little ability to eliminate the superoxide free radicals after BDO, whereas the lipid peroxidation products increase. It may be one of the mechanisms of liver damage after BDO.
Objective To study the effects of malondialdehyde (MDA), superoxide dismutase (SOD) and tumor necrosis factor-α (TNF-α) on brain tissue in rats with pancreatic encephalopathy (PE). Methods Thirty-six Wistar rats were randomly divided into control group (n=6) and PE model group (n=30). In control group, rats were injected with normal saline by internal carotid artery (0.1 ml/100 g) and were killed on the first day after the injection. In PE model group, rats were injected with phospholipases A2 (0.1 ml/100 g, 1 000 U/0.1 ml) by internal carotid artery, to establish animal model of PE in rat and 10 rats were killed on day 1, 3, 7 respectively after the injection. The changes of water content in the brain were measured. Leucocytes aggregation and margination in the microvessels, and the changes of cerebral cells and nerve fibers were observed. The levels of MDA, TNF-α and the activity of SOD were tested in the brain homogenate in rats. Results In PE model group, water contents of brain increased; The phenomena of leucocytes accumulation and margination, cellular edema of neurons and demyelination of nerve fibers became more obvious; The levels of MDA and TNF-α increased significantly than those in the control group, while the activity of SOD reduced (P＜0．05， P＜0.01)． Conclusion Inthe rat model of PE, MDA, SOD, and TNF-α play important roles on the occurrence and development of brain injury.
Objective To study the effect of various doses of estrogen on tissue injury, blood supply and survival area of skin flap and to investigate its mechanism. Methods Thirty New Zealand white rabbits aged 3-4 months old and weighing 1.5-2.2 kg (male or female) were used. Random pattern skin flap (12 cm × 3 cm in size) taking the central l ine of the rabbit dorsum as axis and with the pedicle attached at the proximal end was prepared, and the flap pedicle division was performed 7 days after operation. The rabbits were divided randomly into three groups (n=10 rabbits per group). At 2, 4, and 6 days after operation, the proximal edge of flap in group A and B received 100 ?g/kg and 50 ?g/kg subcutaneous injection ofestradiol benzoate, respectively, while group C received no further treatment serving as control group. General condition ofthe rabbits was observed after injection, gross observation was performed 3 and 7 days after injection, survival area of the skin flap was measured 7 days after injection, contents of malondialdehyde (MDA) and nitric oxide (NO) were tested 5 days after injection, and the flaps were harvested 4 and 7 days after injection to receive histology and no significant difference was noted between group A and group B (P gt; 0.05). The NEU counts 4 days after injection were (18.20 ±6.24) cells/HP in group A, (21.27 ± 5.34) cells/HP in group B, and (28.78 ± 7.92) cells/HP in group C, and at 7 days after injection, there were (15.16 ± 7.02) cells/HP in group A, (18.12 ± 6.44) cells/HP in group B, and (29.67 ± 9.12) cells/HP in group C. The VEGF score 4 days after injection was (4.02 ± 0.48) points in group A, (4.19 ± 0.66) points in group B and (3.67 ± 0.49) points in group C, and at 7 day after injection, it was (4.96 ± 0.69) points in group A, (5.12 ± 0.77) points in group B, and (3.81 ± 0.54) points in group C. Significant difference was evident between 4 days and 7 days after injection in group A or B in terms of NEU counts and VEGF score (P lt; 0.05), and difference between 4 days and 7 days after injection in group C was not significant (P gt; 0.05), and the differences among 3 groups were significant (P lt; 0.05). Conclusion Estrogen injection can increase VEGF expression and NO content of flap, decrease MDA content and NEU infiltration of flat, and improve survival area of flap.
Objective To investigate the protective effects of endotoxin pretreatment on lung injury of rats with endotoxemia. Methods The rat model of acute endotoxemia was established by injecting lipopolysaccharide (LPS) intraperitoneally. Seventy-two male Wistar rats were randomly divided into three groups, ie. a saline control group (N, n=24) , a LPS-treated group (L, n=24) , and a LPS pretreated group ( P, n=24) . Each group was divided into 2 h, 4 h, 6 h, and 12 h subgroups. The rats in group P were firstly administered with introperitoneal injection of 0.25 mg/kg LPS. After 24 hours, they were subjected to the injection of 0.5 mg/kg LPS. The rats in group N and L received injection of equivalent amount of saline. After 72 hours, the rats in group L and P were challenged with intravenous injection of 10 mg/kg LPS, otherwise saline in group N. Six rats were killed at 2, 4, 6 and 12 hours respectively after injection of LPS in group L and P. The lungs were removed for detecting intercellular adhesion molecule-1 ( ICAM-1) , superoxide dismutase ( SOD) , and malondialdehyde (MDA) . Meanwhile the level of tumor necrosis factoralpha ( TNF-α) in serum was measured, and the pathological changes of lung were also examined. Results The contents of ICAM-1, MDA and TNF-α in the LPS-treated 4 h group were 75.07 ±0. 53, ( 3.93 ± 0.42) μmol/g, and (478.62 ±45.58) pg/mL respectively, significantly higher than those in the saline control group. The endotoxin pretreatment reduced the above indexes to 42.40 ±0.44, ( 2.89 ±0.49) μmol / g and ( 376.76 ±43.67) pg/mL respectively (Plt;0.05) . The content of SOD in the LPS-treated 4 h group was ( 6.26 ±0.31) U/mg, significantly lower than that in the saline control group. The endotoxin pretreatment increased SOD to ( 8.79 ±0.35) U/mg. Conclusion Endotoxin pretreatment can suppress the progress of lung injury in rats with endotoxemia and protect the lung tissue by down-regulating the inflammatory response and oxygen free radical production.
Objective To investigate the effects of ecdysterone on the survival of the dorsal random-pattern skin flap with large length-to-width ratio in rats and its possible mechanisms. Methods Twenty-four healthy adult SD rats (male and/or female) weighing 200-250 g were randomly divided into the experimental group and the control group (n=12 per group).A caudally based dorsal random pattern skin flap, measuring 8 cm × 2 cm, was symmetrically raised. Ecdysterone (5 mg/kg) and normal sal ine (5 mg/kg) were injected into the abdominal cavity of rats in the experimental group and the control group at 10 minutes before operation and from the first to the fifth day after operation, respectively. The general condition of the rats was observed after operation. At 7 days after operation, the survival rate of the flap was detected, the superoxide dismutase (SOD) activity and the malonyldialdehyde (MDA) level were tested, HE and immunohistochemistry staining observation of the flap were performed. VIII factor dried microvessels in the middle part of the flap (4 cm far away from pedicle) were counted. Results All the rats survived until the end of the experiment. At 7 days after operation, the survival rate of the flap was 62.323% ± 7.046% in the experimental group and 47.753% ± 2.952% in the control group (P lt; 0.001); SOD activity was (54.560 ± 4.535) U/mgprot in the experimental group and (23.962 ± 3.985) U/mgprot in the control group (P lt; 0.001); MDA level was (8.445 ± 0.992) nmol/mgprot in the experimental group and (14.983 ± 0.929) nmol/mgprot in the control group (P lt; 0.001). Histology observation: compared with the control group, the inflammatory cells infiltration was less and the hyperplasia of fibers was more obvious in the experimental group. The microvessel counting in the middle part of the flap was 17.817 ± 2.420 in the experimental group and 8.967 ± 2.000 in the control group (P lt; 0.001). Conclusion Perioperative intraperitoneal injection of ecdysterone can promote the survival of the random-pattern skin flaps with large length-to-width ratio. Its mechanism may be related to its effects of improving SOD activity, decreasing l ipid peroxidation, and promoting angiogenesis of skin flaps.
【Abstract】 Objective To investigate the protective role of recombinant human growth hormone (rhGH )in ischemic reperfusion injury of rat liver and its mechanism. Methods One hundred Male rats were randomly divided into two groups: the rhGH group and the control group. In the rhGH group, rhGH were injected （0.2U/100g weight） to rats seven days before the ischemic reperfusion injury, and in the control group, normal saline was injected instead. Serum levels of ALT， TNF-α and IL-1α were tested. Hepatic tissue was sectioned for to detect the level of EC and MDA, the expression of NF-κB and ICAM-1 mRNA on SEC. Ultrastructural characteristics histopathological characteristics were determined also. Results Serum levels of ALT, TNF-α, IL-1α and the contents of MDA in the control group were significantly higher than those in the rhGH group （P＜0.05）. Comparied with control group, rhGH also decreased NF-κB activation, and reduced the expression of ICAM-1 mRNA of SEC in the liver cells （P＜0.05）. Electronic microscopic revealed that the hepatic sinusoidal endothelial cells and the hepatocellular mitochondria were injured in the control group. Pretreatment with the rhGH was able to significantly improved the pathological changes. Conclusion rhGH might confer the protection to ischemic reperfusion injury of rat liver through reducing the expression of NF-κB to down-regulate cytokine (IL-1α,TNF-α), MDA and inhibition the expression of ICAM-1 mRNA.
Objective To investigate the effects of glutathione (GSH) on survival of the random skin flap in rats and the probable mechanism that contribute to this effect. Methods Twenty SD rats with 200-250 g in weight, were randomly divided into the experimental group and control group(n=10). Random flap of 8 cm×2 cm in size was made on the back of each rat with the pedicel on the angular of the scapular. GSH(250 mg/kg) and NS of the same dose were injected into the abdominal cavity of rats in the experimental groupand the control group immediately after the operative, 1st and 2nd days respectively. The rats were killed on the 7th day after the operation. The tissue pathology, the survival rate of the flap, the superoxide dismutase(SOD) activity and malonyldialdehyde (MDA) level were compared between two groups. Results The mean survival rate of the flap on the 7th day in the experimental group（56.77%±10.67%） was higher than that in the control group(40.16%±7.12%)(Plt;0.05).SOD activity in experimental group （306.06±84.87 U/mgprot）was higher than that in the control group （224.79±27.12 U/mgprot）, while MDA level （3.835±0.457 nmol/mgprot）was lower than that in the control group (6.127±0.837 nmol/mgprot)(Plt;0.05). Histological observation showed that the neutrophil infiltration was less in experimental group than that in the control group; that the experimental group was surperior to the control group in angiogenesis, fibroblasts, fair cells and cuaneous gland. Conclusion The intraperitoneal use of GSH may promote the survival rate of the random flaps and the possible mechanism for improvement may lies in that the GSH can reduce the level of oxygen free radical and lipidperoxidation,and lessen neutrophil infiltration.
目的:研究大豆異黃酮對D半乳糖致衰老大鼠抗氧化能力的影響。方法:用D半乳糖注射Wistar雄性大鼠5個月,建立衰老模型。對致衰老模型組、大豆異黃酮組肝臟、心臟和前列腺丙二醛(MDA)含量、超氧化物歧化酶(SOD)、谷胱甘肽過氧化酶(GSHPx)活性進行測定及比較。結果:低、中、高不同劑量大豆異黃酮灌喂組與模型組大鼠相比,各臟器MDA含量(μmol/L)(心臟:695±093,562±112,435±112比802±111;肝臟:815±085,647±120,515±112比935±135;前列腺:715±092,558±115,423±125比833±124)均有降低,差異有統計學意義(Plt;005),而SOD酶活性(nmol/L)(心臟:4732±308,5518±428,6120±368比3225±370;肝臟:18121±506,19015±706,19720±570比17213±512;前列腺:4156±301,4607±421,5015±335比3374±305)和GSHPx酶活性(nmol/L)(心臟:905±096,1111±245,1313±146比713±151;肝臟:902±105,1150±223,1362±192比698±160;前列腺:435±085,613±102,747±155比312±106)有升高,差異同樣具有統計學意義(Plt;005);大豆異黃酮攝入量越高,MDA含量越低,而SOD、GSHPx酶活性越高。結論:攝入適量大豆異黃酮可有效增強大鼠機體抗氧化能力,從而延緩D半乳糖誘發的大鼠衰老。