The role of protein oxidation in the development of diabetic microvascular complications.

OBJECTIVE: The role of protein oxidation in the development of diabetic microvascular complications was investigated. METHODS: In total, 266 participants were split into five groups: Group 1; diabetes mellitus for at least 10 years without any complications, Group 2; diabetic nephropathy, Group 3; diabetic neuropathy, Group 4; diabetic retinopathy, and Group 5; control group. Thiol, disulfide, ferroxidase, and ischemia-modified albumin (IMA) levels were analyzed in the serum. RESULTS: Native thiol, total thiol, and native thiol/total thiol were lower in Group 4 than Groups 1, 3, and 5 (p<0.001). However, disulfide/native thiol and disulfide/total thiol were higher in Group 4 than all other groups (p<0.001). IMA was higher in Groups 3 and 4 than all other groups (p<0.001). Ferroxidase was lower in Groups 3 and 4 than Group 2 (p<0.001). CONCLUSION: Thiol-disulfide homeostasis impairment in favor of disulfide may have a function in the progress of diabetic retinopathy. Furthermore, the disruptions of IMA and ferroxidase levels involve in the development of diabetic retinopathy and neuropathy.

A novel therapeutics agent: antioxidant effects of hydroxylfasudil on rat kidney and liver tissues in a protamine sulphate-induced cystitis rat model; preliminary results.

Cystitis is defined as an inflammation of the bladder caused by a bacterial infection, and it can be dangerous and painful when it spreads through the internal organs. In this study, antioxidant effects of hydroxylfasudil (HF) at the enzymatic and molecular level on kidney and liver tissues in cystitis rat model, which is caused by inflammation of the rat bladder with a protamine sulphate (PS), was examined. Quantitative changes of reduced glutathione (GSH) and lipid peroxidation (LPO) levels, which are a marker for oxidative stress, were determined in rat kidney and liver tissues for each groups. And then molecular and biochemical impact of HF treatment on antioxidant enzymes including superoxide dismutase (SOD) and catalase (CAT) in cystitis model were studied. The results suggest that HF could be beneficial to the renal and hepatic antioxidant system. Thus, HF might be used as a novel therapeutics agent to eliminate interstitial cystitis.

The investigation of plasma glucose-6-phosphate dehydrogenase, 6-phoshogluconate dehydrogenase, glutathione reductase in premenauposal patients with iron deficiency anemia.

BACKGROUND AND OBJECTIVE: Iron is an essential element that is necessary for all cells in the body. Iron deficiency anemia (IDA) is one of the most common nutritional disorders in both developed and developing countries. The glutathione pathway is paramount to antioxidant defense and glucose-6-phosphate dehydrogenase (G6PD)-deficient cells do not cope well with oxidative damage. The goal of this study was to check the activities of G6PD, 6-phosphogluconate dehydrogenase, glutathione reductase in patients with IDA. METHODS: We analyzed the plasma samples of 102 premenopausal women with IDA and 88 healthy control subjects. Glucose-6-phosphate dehydrogenase and 6-phosphogluconate dehydrogenase activity as compared to the reduction of NADP +, glutathione reductase activity was performed based on the oxidation of NADPH. 2 ml of plasma were used in all analyzes. SPSS program was used for all of the statistical analysis. RESULT: Diagnosis of iron deficiency in patients belonging to the analysis of blood were ferritin 3.60 ± 2.7 ng / mL, hemoglobin 9.4 ± 1.5 mg / dl and hematocrit 30.7 ± 4.1% ratio; in healthy subjects ferritin 53.5 ± 41.7 ng/ml, hemoglobin level 13.9 ± 1.3 mg / dl and hematocrit ratio 42 ± 3.53%. When compared to healthy subjects the glutathione reductase level (P<0.001) was found to be significantly higher in patients with IDA. IDA patients with moderate and severe anemia had lower GR activity when compared to IDA patients with mild anemia. But the plasma levels of glucose-6-phosphate dehydrogenase (P<0,600) and 6-phosphogluconate dehydrogenase (P<0,671) did not show any differences between healthy subjects and in patients with IDA. CONCLUSION: It was shown that Glucose-6-Phosphate Dehydrogenase and 6-Phosphogluconate Dehydrogenase have no effect on iron-deficiency anemia in patients. The plasma GR levels of premenopausal women with IDA were found to be higher compared to healthy subjects, which could be secondary to erythrocyte protection against oxidative stress being commonly seen in IDA.

Effects of some drugs on human cord blood erythrocyte carbonic anhydrases I and II: an in vitro study.

In this [corrected] study, we purified hcbCA I and II from human cord blood erythrocytes using [corrected] Sepharose-4B-l [corrected] tyrosine-sulfanilamide affinity gel chromatography. [corrected]. The inhibition effects of ampicillin sulfate, ceftriaxone, ceftizoxime and ranitidine on hcbCA I and hcbCA II were also monitored. [corrected]. IC(50) values for ceftriaxone, ceftizoxime and ranitidine were found to be 27.l, 79.4 and 55.5 µM, respectively, [corrected] for hcbCA I, and [corrected] 21.0, 79.1 and 66.1 µM, respectively, [corrected] for hcbCA II. [corrected]. According to these results, ampicillin [corrected] sulfate inhibited only hcbCAII and IC(50) value [corrected] of this antibiotic was found to be 56.8 µM. All [corrected] substances were found to be [corrected] non-competitive inhibitors. It is important to study the inhibition effects of these drugs on hcbCA I and II izoenzymes as pregnant women are often prescribed these antibiotics. [corrected]. For this reason, the dosage of [corrected] these drugs should be carefully evaluated [corrected] to minimize side effects.

Effects of nicotine and vitamin E on 6-phosphogluconate dehydrogenase activity in some rat tissues in vivo and in vitro.

The aim of this study was to investigate whether nicotine affects 6-phosphogluconate dehydrogenase (6PGD) enzyme activity in some rat tissues, and to see the modulatory effects of vitamin E on this effect in vivo. In addition, the effects of nicotine and vitamin E on 6PGD activity were also tested in vitro. The groups were: nicotine [0.5 mg/kg/day, intraperitoneal (i.p.)]; nicotine + vitamin E [75 mg/kg/day, intragastric (i.g.)]; and control group (receiving only vehicles). There were eight rats per group and supplementation period was 3 weeks. The results of in vivo study showed that nicotine activated the muscle, lungs, and testicular 6PGD enzyme activity but had no effect on heart and liver 6PGD activity. Also, nicotine + vitamin E activated the muscle, testicle, and liver 6PGD enzyme activity, while this combination had no effect on heart, and lungs in vivo. When nicotine is administered with vitamin E the increase in 6PGD enzyme activity in muscle and testicles were lower. On the other hand the increase in 6PGD enzyme activity was eliminated by vitamin E in lungs, while 6PGD enzyme activity was increased by vitamin E, which was not affected by nicotine only. In vitro results correlated well with in vivo experimental results. Our results suggest that vitamin E may favourably increase 6PGD enzyme activity in liver in nicotine treated rats, while it has negligible effects on this enzyme activity in other tissues.

The effect of ethanol on erythrocyte carbonic anhydrase isoenzymes activity: an in vitro and in vivo study.

The ethanol is a widely consumed as sedative-hypnotic drug throughout the world. In this study, the effects of ethanol were investigated on carbonic anhydrase (CA) enzyme activities both in vitro in human erythrocyte and in vivo in Sprague-Dawley rat erythrocyte. For in vitro study, the human carbonic anhydrase-I (HCA-I) and -II (HCA-II) are purified by Sepharose 4B-L-tyrosine-sulphanilamide affinity chromatography. In vivo CA enzyme activity was determined colorimetrically by using CO(2)-hydration method of Wilbur and Anderson. Rat blood samples were taken from each rat before and after the ethanol administration at different times (1 h, 3 h, and 5 h). Rat erythrocyte CA activity was significantly inhibited by pharmacological dosage of the ethanol (2 mL.kg(- 1)) for up to 3 h (p < 0.001) following intraperitoneally administration. The ethanol showed in vitro inhibitory effects on HCA-I and HCA-II hydratase activity, determined by colorimetrically using the CO(2)-hydratase method. The inhibitor concentrations causing up to 50% inhibition (IC(50)) were 2.09 M for HCA-I (r(2):0.9273) and 1.83 M for HCA-II (r(2):9749). In conclusion, it was demonstrated that carbonic anhydrase enzyme in erythrocytes was significantly inhibited by the ethanol both in in vitro and in vivo.

Effects of some drugs on hepatic glucose 6-phosphate dehydrogenase activity in Lake Van fish (Chalcalburnus tarischii Pallas, 1811).

Inhibitory effects of some drugs on hepatic glucose 6-phosphate dehydrogenase from Lake Van fish (chalcalburnus tarischii pallas, 1811) were investigated. For this purpose, initially liver glucose 6-phosphate dehydrogenase was purified 899-fold in a yield of 46.24% by using 2',5'-ADP Sepharose 4B affinity gel. In order to control the purification of enzyme was done SDS polyacrylamide gel electrophoresis. SDS polyacrylamide gel electrophoresis showed a single band for enzyme. A constant temperature (+4 degrees C) was maintained during the purification process. Enzyme activity was determined with the Beutler method by using a spectrophotometer at 340 nm. Vankomycine, sulfanylamide, sulfanylacetamide, nidazole, ciprofloxacin, amoxicillin and KMnO(4) were used as drugs. These drugs exhibited inhibitory effects on the enzyme. IC(50) values of vankomycine, sulfanylamide, sulfanylacetamide, nidazole, ciprofloxacin, amoxicillin and KMnO(4) were 1.88, 0.037, 0.032, 1.178, 2.26, 643.5 and 0.0002 mM, and the K(i) constants 1.18+/-0.148, 0.119+/-0.021, 0.075+/-0.015, 1.15+/-0.21, 7.69+/-0.67, 1007+/-69, and 0.001+/-0.00022 mM, respectively. While vankomycine and nidazole showed competitive inhibition, others displayed noncompetitive inhibition. K(i) constants and IC(50) values for drugs were determined by Lineweaver-Burk graphs and plotting activity percentage versus [I], respectively.

Effects of some metal ions on human erythrocyte glutathione reductase: an in vitro study.

In this study, we investigated inhibitory effects of some metal ions on human erythrocyte glutathione reductase. For this purpose, initially human erythrocyte glutathione reductase was purified 1051-fold in a yield of 41% by using 2', 5'-ADP Sepharose 4B affinity gel and Sephadex G-200 gel filtration chromatography. SDS polyacrylamide gel electrophoresis was done in order to control the purification of enzyme. SDS polyacrylamide gel electrophoresis showed a single band for enzyme. A constant temperature (4 degrees C) was maintained during the purification process. Enzyme activity was determined with the Beutler method by using a spectrophotometer at 340 nm. Hg(2+), Cd(2+), Pb(2+), Cu(2+), Fe(3+) and Al3+ exhibited inhibitory effects on the enzyme in vitro. K(i) constants and IC(50) values for metal ions were determined by Lineweaver-Burk graphs and plotting activity % vs. [I]. IC(50) values of Pb(2+), Hg(2+), Cu(2+), Cd(2+), Fe(3+) and Al(3+) were 0.011, 0.020, 0.0252, 0.0373, 0.209 and 0.229 mM, and the Ki constants 0.0254+/-0.0027, 0.0378+/-0.0043, 0.0409+/-0.0048, 0.0558+/-0.0083, 0.403+/-0.043 and 1.137+/-0.2 mM, respectively. While Pb(2+), Hg(2+), Cd(2+) and Fe(3+) showed competitive inhibition, others displayed noncompetitive inhibition.