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Effect of oxygen inhalation on the retinae of newborn rats and its mechanism

Objective To explore the effect of oxygen inhalation on the retinae of newborn rats and its mechanism.Methods We mimicked the retinopathy of prematurity(ROP) by putting the newborn rats in high concentrated oxygen. One-day old rats were put into the oxygen box with the oxygen concentration of 80% for continuous 7 days; then in air condition for 7 days. The arterial blood oxygen pressure, retinal superoxide dismutase (SOD), and malondialdehyde (MDA) of the rats (1,2,4,7,8,9,11,14 days old) were examined. The diameter of retinal vessels′main branch and the coverage rate of peripheral vessels were measured in 7- and 14-day-old rats by ink perfusion. The retinal neovascularization of rats (8,9,11, 14 days old) were observed by HE staining. The rats of the same age fed in air condition were in the control group.Results The differential pressures of blood oxygen of rats (1,2,4,7 days old) in study group were significantly higher than those in the control group (P＜0.01), while the differential pressures of blood oxygen of rats (8,9,11,14 days old) in study group were lower than those in the control group (P＞0.05). The contents of SOD of the retinae in the rats ( 1,2,4,7,8 days old) were significantly lower than those in the control group(P＜0.01, P＜0.05 ), while the contents of MDA were significantly higher than those in the control group (P＜0.01,P＜0.05). The diameter of retinal vessels′main branch in 7-day rats was 75% of the control group, and the coverage rate of peripheral vessels was 22% of the control group; and was 61% and 73% respectively in 14-day-old rats. The neovascularization could be seen in 16.7% of the rats in the study group and nought in the control group.Conclusion The damage of free radical of the retina in high concentrated oxygen and hypoxia situation after oxygen supply may be one of the most important mechanism of ROP. (Chin J Ocul Fundus Dis，2003，19：269-332)

IMPROVEMENT EFFECT OF ESTROGEN ON FLAP REPERFUSION INJURY AND BLOOD SUPPLY

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.

Influence of chronic alcohol intake on acute lung injury in rats

Objective To investigate the influence of chronic alcohol ingestion on the severity of acute lung injury (ALI) induced by oleic acid and lipopolysaccharide (LPS).Methods Thirty-two SD rats were randomly administrated with alcohol or water for 6 weeks，then instilled with oleic acid and LPS to induce ALI or with normal saline as control.Thus the rats were randomly divided into two injury groups [ethanol group and water group] and two control groups [ethanol group and water group] (n=8 in each group). PaO2,Wet to dry lung weight ratio (W/D)，levels of γ-glutamylcysteinylglycine (GSH) and malonaldehyde (MDA) in the lung tissue were measured.Results Compared to corresponding control groups，the PaO2 and GSH significantly decreased，and the lung W/D and MDA level were significantly increased in the injury groups (all Plt;0.05).In the injury groups，the changes of above parameters were more significant in the alcohol group than thoe in the water group (all Plt;0.05)，except the lung W/D with no significant difference.Conclusion Chronic ethanol ingestion was relevalent to oxidation/ antioxidation imbalance and more severe lung injury in rats with severe septic after trauma,which suggests that chronic alcohol abuse could increase the severity of acute lung injury.

The histochemistry changes in rat retinal photochemical damage of rat

Objective：To observe the histochemical changes of retinal photochemical damage in rats. Methods：The changes of retinal ultrastructure were observed.The concentration of malondaldehyde(MDA) was tested and the activity the histochemical change of cytochrome oxidase (CCO) and (Mg ++ -ATPasw) were evaluated on the retnal photochemical damage in SD rats. Results：At the 6th hour after light exposure,the swelling appwared at the nuclei of photoreceptor,the mitochondria of inner segment.The apical microvilli of RPE disappeared and lysosomes increased in RPE.On the 6th day after light exposure,the changes became more obvious.While on the 14th day after light expose the nuclei of photoreceptors and the inner segments renewed but the arrangement of the disk was lose;and the microvilli appeared of the disk was lose;and the microvilli appeared at the tip of RPE.The Activity of CCO and Mg ++ -ATPase decreased and MDA increased in retina at the 6th hour and on the 6th day and they recovered on the 14th day after light exposure. Conclusion：Lipd peroxidation that broke the cell membrane system of photoreceptor which induced changes of the cell ultrastru cture abd the activity of enzyme might relate to pathogenesis in retinal photochemical damage. (Chin J Ocul Fundus Dis,1998,14:38-40)

Protective Effects of Epidermal Growth Factor on Pancreas of Rats with Acute Pancreatitis

【Abstract】Objective To investigate the protective effects of epidermal growth factor (EGF) on pancreas of rats with acute pancreatitis(AP). Methods Seventytwo male SpragueDawley rats were randomly divided into 3 groups: Control group, AP group and AP-EGF group. Subcutaneously injection of EGF (0.1 μg/g) were given to animals in the AP-EGF group after the establishment of the model of AP. The other two groups of animals received the same volume of saline. At 6 h, 12 h and 24 h after induction of AP, 8 animals in each group were sacrificed respectively， 4 ml of blood sample was withdrawn from heart，2 ml for the analysis of amylase activity and 2 ml for MDA content in serum. Ascites was sucked with dry gauzes and was weighed thereafter. Changes of pancreas morphology were evaluated at every time point. The same part of pancreas was removed for measurement of MDA content, apoptotic index (AI) and histologic changes. Results Histologic injury of the animals in the APEGF group was milder than that in the AP group. Ascites weight in the AP-EGF group decreased significantly compared with that in the AP group at 12 h and 24 h 〔(4.53±1.29) g vs (6.58±1.47) g, (7.64±1.85) g vs (11.96±2.13) g，P＜0.05，P＜0.01〕. Amylase activity in the APEGF group also decreased significantly compared with that in the AP group at 12 h and 24 h 〔(142.0±8.3) U/L vs (187.9±10.4) U/L, (194.3±10.4) U/L vs (253.3±8.6) U/L, P＜0.05，P＜0.01〕. MDA content in plasm 〔(2.34±0.23) μmol/L vs (3.15±0.38) μmol/L, P＜0.05〕 and in pancreas 〔(5.21±1.46) μmol/g vs (7.68±1.63) μmol/g, P＜0.01〕 in the APEGF group decreased significantly compared with those in the AP group at 24 h. AI of pancreas in the APEGF group increased significantly compared withthatintheAPgroupafteroperation〔(16.22±3.53)%〖KG4vs (7.35±1.04)%, (11.67±2.40)% vs (4.81±0.86)%, (6.38±1.42)% vs (1.97±0.21)%, P＜0.01〕. Conclusion EGF may accelerate the restoration of pathologic injury and alleviate the hemorrhage and edema of pancreas. It may also depress MDA content in plasm and in pancreas so that to lessen oxidative damage. EGF may protect pancreas by inducing cellular apoptosis.

VARIATIONS OF LIPID PEROXIDATION PRODUCTS AND COPPER, ZINC-SUPEROXIDE DISMUTASE INPATHOLOGICAL SCARS

To study the variations of l ipid peroxidation products and copper, zinc-superoxide dismutase(CuZn-SOD) in pathological scars (hypertrophic scars and keloids). Methods The specimens were gained from patients of voluntary contributions from May 2005 to August 2005. The tissues of hypertrophic scar (10 cases, aged 16-35 years, the mean course of disease was 2.2 years), keloid (10 cases, aged 17-32 years, the mean course of disease was 8 months) and normal skin (8 cases, aged 16-34 years) were obtained. The content of malonaldehyde (MDA)and CuZn-SOD activity were detected by spectrophotometric method. The expression of CuZn-SOD was evaluated by immunohistochemistry technique. Results The contents of MDA and CuZn-SOD activity were significantly higher in hypertrophic scars[MDA (1.139 0 ± 0.106 7)nmoL/mg prot, CuZn-SOD (31.65 ± 2.21)U/mg prot, (P lt; 0.05)]and keloids[MDA (1.190 0 ± 0.074 8)nmoL/ mg prot, CuZn-SOD (34.36 ± 5.01)U/mg prot (P lt; 0.05)] than those of normal skin tissues [MDA (0.821 3 ± 0.086 4)nmoL/mg prot, CuZn-SOD (20.60 ± 5.56)U/mg prot]. Immunohistochemical studies indicated that the brown particles were CuZn-SOD positive signals, which mainly located cytoplasm in normal skin tissues, hypertrophic scars as well as keloids epidermal keratinocytes and dermal fibroblasts. CuZn-SOD expression evaluation in hypertrophic scars (4.14 ± 0.90, P lt; 0.05) and keloids epidermal keratinocytes (4.43 ± 0.79, P lt; 0.05) markedly increased when compared with normal skin tissues (2.20 ± 0.45). The expression of CuZn-SODin hypertrophic scars (4.00 ± 0.82, P lt; 0.05) and keloids dermal fibroblasts (4.43 ± 0.53, P lt; 0.05) were significantly higher than that of normal skin tissues (1.60 ± 0.89). There were no differences in the content of MDA, CuZn-SOD activity and expression evaluation between hypertrophic scars and keloids (P gt; 0.05). Conclusion In pathological scars, the contents of MDA and CuZn-SOD activity increase and the expressions of CuZn-SOD are enlarged.

Effects of Soybean Isoflavones on Antioxidative Action in Aged Rats

目的:研究大豆异黄酮对D半乳糖致衰老大鼠抗氧化能力的影响。方法:用D半乳糖注射Wistar雄性大鼠5个月,建立衰老模型。对致衰老模型组、大豆异黄酮组肝脏、心脏和前列腺丙二醛(MDA)含量、超氧化物歧化酶(SOD)、谷胱甘肽过氧化酶(GSHPx)活性进行测定及比较。结果:低、中、高不同剂量大豆异黄酮灌喂组与模型组大鼠相比,各脏器MDA含量(μmol/L)(心脏:695±093,562±112,435±112比802±111;肝脏:815±085,647±120,515±112比935±135;前列腺:715±092,558±115,423±125比833±124)均有降低,差异有统计学意义(Plt;005),而SOD酶活性(nmol/L)(心脏:4732±308,5518±428,6120±368比3225±370;肝脏:18121±506,19015±706,19720±570比17213±512;前列腺:4156±301,4607±421,5015±335比3374±305)和GSHPx酶活性(nmol/L)(心脏:905±096,1111±245,1313±146比713±151;肝脏:902±105,1150±223,1362±192比698±160;前列腺:435±085,613±102,747±155比312±106)有升高,差异同样具有统计学意义(Plt;005);大豆异黄酮摄入量越高,MDA含量越低,而SOD、GSHPx酶活性越高。结论:摄入适量大豆异黄酮可有效增强大鼠机体抗氧化能力,从而延缓D半乳糖诱发的大鼠衰老。

Levels of Malonaldehyde, Interleukin-8 and Tumor Necrosis Factor-αin Lung Tissues from Patients with and without Chronic Obstructive Pulmonary Disease and Effects of Cigarette Smoking

Objective To observe the levels of malonaldehyde (MDA) , interleukin-8 (IL-8) and tumor necrosis factor-α(TNF-α) in lung tissues of subjects with or without chronic obstructive pulmonary disease (COPD) , and investigate their roles in the the pathogenesis of COPD. Methods The content of MDA, IL-8 and TNF-αin lung tissues of smokers with COPD (n=9) , ex-smokers with COPD (n=8) , non-smokers with COPD (n=7) , healthy smokers (n=9) , healthy ex-smokers (n=8) and healthy nonsmokers (n=6) was measured with enzyme-linked immunosorbent assay ( ELISA) and corrected by creatinine. Results The levels of MDA, IL-8 and TNF-α in lung tissues of the COPD patients were significantly higher than those in the healthy subjects (Plt;0.05) , which were also significantly higher in the smokers when compared with the non-smokers (Plt;0.05) , whether suffering from COPD or not. In the COPD patients, not the levels of IL-8 but MDA and TNF-αin lung tissues of the smokers were significantly higher than those in the ex-smokers (Plt;0.05) ; whereas in the healthy cases, no statistical significance was revealed between the smokers and the ex-smokers on the levels of MDA and IL-8 in lung tissues except TNF-α( Pgt;0.05) . Conclusion The abnormal increase of MDA, IL-8 and TNF-αin lung tissues caused by chronic smoking may play an important role in the the pathogenesis of COPD.

眼前段碱烧伤后视网膜病理改变及氧自由基反应

CHANGES OF LIVER SUPEROXIDE DISMUTASE AND MALONDIALDEHYDE CONTENTS AFTER BILE DUCT OBSTRUCTION

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.