Masaru Sonoda

Bezafibrate has an antioxidant effect: Peroxisome proliferator-activated receptor α is associated with Cu2+, Zn2+-superoxide dismutase in the liver

Administration of bezafibrate in rats significantly reduced the levels of plasma thiobarbituric acid-reactive substances (TBARS) in comparison with those obtained in rats fed a soy or lard chow. Moreover, an elevation of in vitro conjugated diene production and linoleic acid levels in the high-density lipoproteins and low-density lipoproteins induced by a soy or lard chow, was reduced by bezafibrate administration. In addition, the liver Cu2+, Zn2+-superoxide dismutase (SOD) gene expression showed a significant positive correlation with the liver peroxisome proliferator-activated receptor alpha (PPARalpha) mRNA level (R=0.769, p<0.0001). This unique characteristic of bezafibrate, which possesses both a hypolipidemic effect and antioxidant activity, may be beneficial in preventing vascular complications in hyperlipidemia.

Significance of increased neutrophils in patients with advanced colorectal cancer

We examined the ratio of neutrophils to lymphocytes (N/L ratio) in the peripheral blood in patients with colorectal cancer. The ability to produce active oxygen and phagocytosis of neutrophils, G-CSF, sIL-2R and IAP (immunosuppressive acidic protein) were also measured. The N/L ratios were significantly higher in the advanced stages of cancer than in normal controls. The ability to produce active oxygen in the terminal stage was 33% lower than in the control group. The G-CSF levels had no relationship with the neutrophil counts. IAP levels increased with cancer stage, and were inversely related to the ability to produce active oxygen. The IAP levels correlated well with the sIL-2R levels and the N/L ratio. These findings suggest that the ability to produce active oxygen, N/L ratio and IAP reflect anticancer mechanisms and that they may be useful when considering treatment or prognosis of patients with advanced stages of cancer.

Significance of superoxide dismutase (SOD) in human colorectal cancer tissue: Correlation with malignant intensity

The significance of superoxide dismutase (SOD) activity in colorectal cancer tissue was determined from the aspect of the antioxidant defense system. SOD activity and thiobarbituric acid reactive substance were measured in the tumor, in tissues adjacent to the tumor, and in regions that appeared normal, and the results were analyzed in terms of various histopathological factors (stage of disease, depth of invasion, venous invasion, etc.). DNA ploidy pattern and cell proliferation in cancer tissue were also measured, and the results analyzed in relation to SOD activity. SOD activity in cancer tissue was higher than in the other two regions. SOD activity in cancer tissue increased with the progression of stage, and changed with the depth of invasion. There was a significant difference in SOD activity between patients with venous invasion and those in whom this was absent. Stepwise regression analysis suggested that venous invasion was the most significant factor influencing SOD activity. The proliferation index was high in cancer tissue with low SOD activity. The incidence of aneuploidy was high in cancer with high SOD activity, whereas the incidence of diploidy was high in cancer with low SOD activity. These results suggest that elucidation of the antioxidant system in cancer tissue can provide us with a better strategy for cancer treatment.

Partial breakdown of glycated alkaline phosphatases mediated by reactive oxygen species.

The lower levels of serum alkaline phosphatase (AP) activity found in patients with diabetes mellitus apparently originate from the selective disappearance or decrease in bone AP activity in the circulation. Hence, we investigated in vitro the effect of glycation on the activities of five AP isozymes. Aseptic incubation with 25 mmol/L of D-glucose and APs rapidly reduced bone and placental AP activities before those of liver, kidney and intestinal enzymes. The resulting bone and placental AP molecules were clearly glycated, according to the result of aminophenylboronic acid affinity chromatography. Furthermore, Western blotting analysis revealed that the placental AP molecule was fragmented, and its partial cleavage took place at Ala154 on the AP molecule. Since glycation of serum proteins causes the generation of reactive oxygen species, the effects of reactive oxygen species on placental AP activity were assayed, and the results indicated that hydroxyl radicals might be a major factor for the specific inactivation of AP activities. The reduction in AP activity by incubation with glucose in vitro was reversed by the further addition of catalase. Furthermore, ferrous ion with hydrogen peroxide, which generates hydroxyl radicals, had an inhibitory effect on AP activities. These findings suggest that the reduced AP activity in diabetic patients might result from partial cleavage of the bone AP molecule by reactive oxygen species induced by glycation.

Diazotization reaction of nitric oxide trapped by hemoglobin

The present study addresses to determine whether hemoglobin within red blood cells can be utilized as a spin-trap agent for nitric oxide. We demonstrate the diazotization method coupled with a gel filtration chromatography, which is simply due to the separation of nitrosylhemoglobin from nitrite, nitrate or other low molecular nitroso-compounds in biological systems and to the liberation of nitric oxide from nitrosyl heme-complexes in the acidic condition. The amount of nitric oxide can be estimated by the difference of absorbances at 542 nm between diazo-compounds formed by Griess reagent and hemichrome by phosphoric acid. Our results indicate that hemoglobin in red cells as a spin-trap agent would be useful for monitoring nitric oxide in the circulation under the several disease states.

Flow analysis of UV-irradiated chemicals by chemiluminescence and electron spin resonance spectroscopy

Abstract A novel method for detecting changes in chemicals, especially radical formation after ultraviolet (UV) irradiation, was developed using imipramine as a marker of light-sensitive materials. The system consisted of a pump, an injection port for the sample, an on-line UV irradiation device and detectors for chemiluminescence and electron spin resonance (ESR). Most chemicals that were chemiluminescence positive after UV irradiation in this flow system were found to show spectra of free radicals by ESR spectroscopy. These results suggested that the proposed on-line system may be useful for the rapid and simple determination of the stability and light-induced degradation of chemicals.

Tissue superoxide dismutase (SOD) activity and immunohistochemical staining in acute appendicitis: Correlation with degree of inflammation

The mechanism of progression of appendicitis has not been clarified. We esamined tissue superoxide dismutase (SOD) activity, thiobarbituric acid reactive substance (TBARS), and the localization of Cu, Zn-SOD in 56 inflamed appendices in relation to histopathological classification. There was a significant difference in SOD activity between catarrhal appendix and phlegmonous and gangrenous appendix (2.3±0.1 vs 5.0±0.2 and 4.6±0.6 units/mg protein, respectivelyP<0.05). TBARS value was highest in gangrenous appendix, being significantly different from the levels in the other two types (0.47±0.40 vs 0.19±0.01 n mol/mg protein, in catarrhal and 0.20±0.02, in phlegmonous appendixP<0.05). Positive staining for Cu, Zn-SOD was demonstrated in 64% of catarrhal appendices, 96% of phlegmonous appendices, and 75% of gangrenous appendices, and intense positive staining was recognized in 9%, 28%, and 40% of these appendices, respectively. These results indicated that active oxygen influences the degree of inflammation in phlegmonous and gangrenous appendicitis. Gangrenous appendicitis and the other two types of appendicits seemed to be different entities.

Inhibition of alkaline phosphatase by bismuth.

The interaction of alkaline phosphatase (EC 3.1.3.1) with bismuth was studied. Among the tested alkaline phosphatases, bismuth was found to be the most effective inhibitor of the placental enzyme. Partial denaturation of the placental enzyme by papain digestion had little effect, if any, on the inhibition. Bismuth inhibition of the placental enzyme activity was more progressive with mixed glycosidase treatment than with sialidase treatment. The pH activity profile of the mixed glycosidase-treated placental enzyme was clearly shifted in the presence of bismuth. The mixed glycosidase-treated placental enzyme/bismuth mixture was more heat labile than the non-treated placental enzyme. Based on the results of kinetic studies, the inhibition mechanism of the placental enzyme by bismuth was shown to be of the competitive type, and the Ki value and Hill coefficient of the mixed glycosidase-treated placental enzyme was found to be 92 mu mol/l and 2.25, respectively. L-Phenylalanine does not interfere with the inhibitory effect of bismuth on alkaline phosphatase. Inorganic phosphate, on the other hand, appears to disturb bismuth bindings.

Estimation of serum tumor necrosis factor-α and tumor tissue superoxide dismutase (SOD) activity in the prognosis of human colorectal cancer

BackgroundSerum tumor necrosis factor-α (TNF) levels were estimated before surgery and tissue SOD levels were determined postoperatively as a means to gauge future prognosis in colorectal cancer patients.MethodsWe examined TNF levels, the ability of neutrophils to produce active oxygen, and cancer tissue superoxide dismutase (SOD) activity. We then investigated the relationships among these mediators and survival rates in 75 patients with colorectal cancer.ResultsTwenty cases were positive for TNF, varying from 6.9 to 472 pg/mL. In the TNF-positive group, all cases except 1 stage III case and those of stage IV were alive. In the TNF-negative group, 29% of stage II, 63% of stage III, and all stage IV patients died. The survival rate except for stage I and stage IV cases was significantly higher in the TNF-positive group, compared with the TNF-negative group (P<0.05). SOD activities of the TNF-negative group were higher than those in the TNF-positive stage II and III group. In the TNF-negative patients, SOD activities were higher in the patients who died than in the survivors. The ability of neutrophils to produce active oxygen in survivors was higher than in the patients who died.ConclusionTNF levels before surgery and tissue SOD activity can influence the postoperative prognosis. The prognosis in patients who are TNF-positive with low tissue SOD activity and neutrophils with a normal ability to produce active oxygen is excellent. Immunopotentiating therapy may be imperative for stage II and III TNF-negative patients with high tissue SOD activity.

Reactive oxygen species and progression of metastasis of VX2 carcinoma implanted in liver

We examined the electron spin resonance (ESR) spectra, tissue superoxide dismutase (SOD) activity, and the capacity of neutrophils to produce active oxygen in a liver metastasis model of VX2 carcinoma. The ESR spectra were similar to the signal of the oxygen radical recognized in liver tissue subjected to transcatheter hepatic arterial embolization. The signal intensity was lower in the metastatic than in the non-metastatic region, and there was a significant difference between the regions 2 weeks after the injection of the carcinoma cells. There were no differences between the SOD activity of the metastatic and non-metastatic regions, assayed weekly. The capacity of neutrophils to produce active oxygen decreased with the progression of metastasis. Our results suggest that the injection of VX2 carcinoma cells into the portal vein induces ischemia after injection. Metastatic cancer cells generated active oxygen (endogenous), at levels that were virtually constant, from 2 to 4 weeks after the injection of cancer cells. After the injection, the progress of metastasis was affected by endogenous active oxygen and by the capacity of neutrophils to produce active oxygen.