The Detection of Oxygen Free Fadical Scavenger, Superoxide Dismutase(SOD) on the Uterine Cervical Tissue / 대한부인종양콜포스코피학회잡지

The superoxide anion, hydrogen peroxide, and hydroxyl radical are oxygen free radicals which arise in cell metabolism and which are toxic to cells, with an important role in carcinogenesis. The measurement of the oxygen free radical is a problem due to the instantaneously changing nature, and therefore the superoxide dismutase(SOD) is employed which act as an oxygen free radical scavenger. The authors quantitatively analyzed the SOD levels in normal uterine cervix epithelium, cervical intraepithelial neoplasia, and in invasive cervical cancer patients by the SOD-525R spectrophotometric assay and compared the results between each group with respect to prognostic variables such as stage of disease, cell type, lymph node involvement, and SCC Ag(TA-4 Ag) levels. The mean SOD levels were 0.41U/ml, 0.39U/ml and 0.73U/ml in the normal uterine cervix, intraepithelial neoplasia, and invasive cervical cancer groups, respectively, showing statistically significant difference by the Oneway anova test(p=0.05). The mean SOD levels according to the stage of disease were 0.5U/ml, 0.62U/ml, and 1. 15U/ml for stages I a, I b, and stage II and above(p=0.029). For the cell type the SOD levels were 0.77/ml for squamous cell carcinoma and 0.57U/ml for adenocarcinoma(p=0.15). For cancer cell lymph node involvement cases, the mean SOD levels were 0.75U/ml and 0.57U/ml for lymph node involvement and no involvement respectively(p=NS). The mean SOD levels also did not show any significance when compared with SCC Ag levels where SOD was 0.78U/ml for SCC Ag levels of more than 2.0ng/ml, and 0.77U/ml for SCC Ag levels of less than 2.0ng/ml. From the above results the authors conclude that SOD levels were higher in invasive cervical cancer tissues compared to intraepithelial neoplasia and normal cervical tissues, that SOD levels increased with higher stage of disease, and that there was no relationship between SOD levels and known prognostic variables such as cell type, lymph node involvement and SCC Ag level.

EFFECTS OF OXYGEN FREE RADICAL SCAVENGERS ON THE HYPOXIA-REOXYGENATION INDUCED PROLIFERATION OF CULTURED HUMAN FIBROBLAST MALME-3 CELL LINE

The aim of this study was to investigate the effect of hypoxia-reoxygenation on the proliferation of fibroblast, and to elucidate the role of oxygen free radicals in this process. Malme-3 fibroblast, derived from human skin fibroblast, was used for this study. The hypoxia or reoxygenation condition was made by exposing cultured cells to the environment of 95% N2, 5% CO2 or 95% room air, 5% CO2, respectively. Cell proliferation was estimated by the cell numbed, and DNA synthesis was measured by the [3H]-thymidine uptake. Release of oxygen free radicals was measured by the means of Ohkawa's method of lipid peroxidation. The effect of oxygen free radicals was confirmed by using dimethylthiourea(DMTU) and alpha-tocopherol, two known oxygen free radical scavengers. The results are as follows: 1. The dissolved oxygen of the culture medium was 8.97+/-1.23 ppm in the normal condition. When the culture dish was exposed to the hypoxic condition for 3 or 6 hours, the dissolved oxygen of the culture medium decreased markedly to the level of 3.10+/-0.46 ppm or 2.37+/-0.47 ppm, respectively 2. The number of cultured cells increased in a hypoxia duration-dependent manner up to 6 hours when the cells were cultured for 24 hours after hypoxia. The same pattern was observed in the cells cultured for 48 hours after hypoxia. Lipid peroxidation in the culture increased after the exposure to hypoxia-reoxygenation. DMTU or alpha-tocopherol blocked the increase in lipid peroxidation induced by the exposure to hypoxia-reoxygenation. 3. [3H]-thymidine uptake of the cultured cells increased after the exposure to hypoxia-reoxygenation. 4. DMTU or alpha-tocopherol blocked the proliferation of fibroblasts induced by the exposure to hypoxia-reoxygenation. The increase in lactate dehydrogenase (LDH) activity was also noted after the exposure to hypoxia-reoxygenation, and this increase was blocked by DMTU or alpha-tocopherol. These results indicate that the hypoxia-reoxygenation induces the proliferation of fibroblasts, and that oxygen free radicals play an important role in this process. Moreover, oxygen free radical scavengers may be of potential therapeutic value in preventing fibrosis.

The Effect of O2 Radical Scavenger (SOD) and Intrarenal Calcium Membrane Blocker (verapamil) in the Renal Function Following Warm Ischemia / 대한비뇨기과학회지

During renal ischemia, ATP is degraded to hypoxanthine. When xanthine oxidase converts hypoxanthine to xanthine in the presence of molecular oxygen, superoxide radical (O2) is generated. This is toxic to cellular membranes through lipid peroxidation and may play an important role in the ischemic damage of the kidney. At the cellular level, with reperfusion there is accumulation of calcium and this potentiates oxygen free radical injury. The purpose of the present study is to determine whether oxygen free radicals and calcium play a role in mediating injury after renal ischemia. The ability of oxygen free radical scavenger (SOD) and calcium membrane blocker (verapamil) to protect renal function in the rabbit after renal ischemia was determined. The New-Zealand white rabbit was explored and occluded both renal arteries for 60 minutes with microvascular clamps. Group 1 (n=7) had normal saline infused into the both renal arteries followed by 60 minutes ischemia, group 2 (n=5) had SOD (10mg/kg) infused into the both renal arteries just before clamping, group 3 (n=5) had verapamil 15mg/kg infused. The results were as follows. Plasma creatinine in the group 2(1.7+/-0.1 mg/dl) was lower than group 1 (2.6+/-0.2 mg/dl) (p<0.05). Creatinine clearance and Ucr/Pcr in the group 2 (4.8+/-0.2ml/min, 19.8+/-2.6) was higher than group 1 (1.5+/-0.1 ml/min, 19.8+/-2.6) (p<0.05). Urine osmolarity in the group 2(574.6+/-22.3 m Osm/kg) was higher than group 1 (342.27+/-84.7 m Osm/kg). The function of solute handling was more reserved in the group 2 than group 1. (FeNa+ of group 1 vs. group 2 ; 6.9+/-0.6, vs. 2.0+/-0.3) (p<0.05). There was no difference between group 1 and 3 except Ccr. From these observations we conclude that free radical scavengers provide significant protection from the injury to the kidney and increased intracellular calcium potentiates renal injury during reperfusion.