Perfusion of free flaps from groin of rabbits, after 12 hours of complete ischemia, with superoxide dismutase (SOD), an oxygen free radical scavenger, would significantly increase the survival rate of these flaps from 18.75% to 75% in the control group. Tissue levels of SOD and malonydialdehyde (MDA, an end product of lipoperoxidation) were measured before ischemia, after ischemia but before reperfusion, and 60 minites after reperfusion. In untreated flap, after 12 hours- ischemia, the SOD content of skin decreased significantly as compared with the SOD content before ischemia, and reperfusion further decreased SOD activity, while the concentration of MDA increased after ischemia and further increased after reperfusion. In the treated flaps, the concentration of SOD was not decrease and MADnot increased after reperfusion. There was a negative correlation between the values of SOD and MDA. These findings suggested that free oxygen radicals playedan important role in the free flap ischemia reperfusion injury. SOD could increase the survival of ischemic free-flaps by reducing lipoperoxidation. The results had significant clinical implications with regard to organ preservation and transplantation.
【Abstract】Objective To investigate the expressions of TNF-α and superoxide dismutase (SOD) mRNA in myocardium of rats with obstructive jaundice (OJ). Methods The expressions of TNF-α and SOD mRNA were semi-quantitatively analyzed after amplification of cDNA in myocardium of the rats with OJ by RTPCR. Results The expression of TNF-α mRNA increased and that of SOD mRNA decreased in the myocardium of rats with OJ. The level of plasm TNF-α increased and SOD synthesis in myocardium decreased. Conclusion The injury of myocardium in OJ is correlated with increasing expression of TNF-α mRNA and decreasing expression of SOD mRNA.
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.
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)
Electron spin resonance (ESR) spectroscopy and spin trapping agent PBN were applied to measure directly the changes of oxygen free redicals (OFR) in gastric mucosa of rats with portal hypertension (PHT) injured by shockreperfusion, and treated with superoxide dismutase (SOD), radix salviae miltiorrhizae (RSM), with concomitant monitoring activity of SOD and pathology of gastric mucosa. Results showed that the amount of OFR increased markedly in gastric mucosa of PHT rats during the shock-reperfusion. The pathological changes were in accordance with alteration of the amount of OFR and the activity of SOD. Gastric mucosa in PHT was more susceptible to shock-reperfusion insult than normal controls. The anti-oxidant SOD, RSM used at early stage exerted mild gastric mucosal insult through different mechanisms.
目的:研究缺氧預處理對老年大鼠子宮及雙附件切除術后疲勞是否有改善作用,并通過對比觀察超氧化物歧化酶及丙二醛水平的變化,初步探討缺氧預處理的作用機制。方法:將老年大鼠分為空白對照組、對照組、缺氧預處理三組。空白對照組為假手術組,對照組為子宮及雙附件切除術組, 缺氧預處理組為缺氧預處理加子宮及雙附件切除術組。對比觀察缺氧預處理對大鼠體力活動及血清超氧化物歧化酶和丙二醛水平的影響。結果:空白對照組、對照組、缺氧預處理三組大鼠懸尾不動時間分別為:(21±3)s,(83±10)s,(44±5)s,各組間比較Plt;0.05。三組SOD活性分別為:(131.23±5.31)U/L,(36.12±9.68)U/L,(73.01±9.82)U/L,各組間比較Plt;0.05。三組MDA水平分別為:(9.78±1.26)μmol/L,(29.87±3.13)μmol/L,(15.98±2.21)μmol/L,各組間比較Plt;0.05。結論:缺氧預處理可提高老年大鼠的抗氧化能力,對老年大鼠子宮及雙附件切除術后疲勞綜合征有明顯的改善作用。
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.