Dehydroepiandrosterone modulates the PTEN/PI3K/AKT signaling pathway to alleviate 4-vinylcyclohexene diepoxide-induced premature ovarian insufficiency in rats.

Dehydroepiandrosterone (DHEA) is frequently integrated as an adjuvant in over a quarter of controlled ovarian hyperstimulation (COH) protocols, despite the ongoing debate regarding its impact. This study aimed to evaluate the efficacy and mechanism of action of DHEA on ovarian follicular development and ovarian response in rats with varying ovarian reserves. The study involved 75 rats categorized into 15 distinct groups. The ovarian tissues of rats in both the normal ovarian reserve group and the premature ovarian insufficiency (POI) group, induced by 4-vinylcyclohexene diepoxide (VCD) injection, were subjected to histomorphological and biochemical analyses following the administration of DHEA, either alone or in combination with COH. Follicle counting was performed on histological sections obtained from various tissues. Serum concentrations of anti-Müllerian hormone (AMH) and the quantification of specific proteins in ovarian tissue, including phosphatase and tensin homolog of chromosome 10 (PTEN), phosphoinositide 3-kinase (PI3K), phosphorylated protein kinase B (pAKT), cyclooxygenase 2 (COX-2), caspase-3, as well as assessments of total antioxidant status and total oxidant status, were conducted employing the ELISA method. The impact of DHEA exhibited variability based on ovarian reserve. In the POI model, DHEA augmented follicular development and ovarian response to the COH protocol by upregulating the PTEN/PI3K/AKT signaling pathway, mitigating apoptosis, inflammation, and oxidative stress, contrary to its effects in the normal ovarian reserve group. In conclusion, it has been determined that DHEA may exert beneficial effects on ovarian stimulation response by enhancing the initiation of primordial follicles and supporting antral follicle populations.

The danger of hyperoxia on the rat kidneys: is tadalafil a real shield?

PURPOSE: Continuous oxygen therapy to compensate for decreased oxygen saturation in the blood is a life-saving treatment used in case lung involvement. Excess oxygen delivery was reported to be a common situation, in which about 50% of the patients showed hyperoxemia and 4% in severe hyperoxemia. In this work, we investigated the effects of hyperoxia on the rat kidneys and whether tadalafil has an effect to reduce this damage. MATERIALS AND METHODS: Three groups of 8 male rats each weighing 300-350 g were formed. The groups were divided into the control group, hyperoxia group, and hyperoxia and tadalafil administered group for 10 days. At the end of the 10th day, blood and kidney samples were taken for biochemical analysis (SOD and NO levels) and histopathological examination. RESULTS: While our findings showed that SOD levels were significantly different among the control and experimental groups and within the experimental groups, no statistical difference was found in terms of NO levels among the groups (Table 1). While the glomerular and tubular injury was higher in the Hyperoxia group and the Hyperoxia + Tadalafil group than in the control group (p < 0.001), as a result of the rate of severe glomerular and tubular injury in the hyperoxia group, was 62.5% and 43.8% and in the group given tadalafil was 43.8% and 31.3%, respectively (Table 2). CONCLUSIONS: Exposure to hyperoxia condition causes renal glomerular and tubular damage, and tadalafil does not show a protective effect on this damage according to this study's dose and exposure time.

Tadalafil against hyperoxia-induced oxidative stress; an experimental study.

This study aimed to investigate the protective effect of tadalafil on reactive oxygen species induced by a hyperoxia model in rats, both in terms of enzymes such as superoxide dismutase (SOD) and nitric oxide (NO), and its pathological effects on the corpus cavernosum. Overall, 24 rats were divided into three groups. The control group (eight rats) was not exposed to any intervention. The second group (eight rats), was exposed to hyperoxia in a hyperoxia cabinet for 8 h a day for 10 days. The third group (eight rats) was exposed to hyperoxia the same as in the second group, tadalafil at a dose of 10 mg/kg was given orally as a dissolved form in water in the amount of 10-12 ml/100 g/day to the rats placed in separate cages having removed from the hyperoxia cabin. SOD levels differ enough to create a difference, but there was no significant difference in terms of NO levels. The SOD level was highest in hyperoxia conditions and lowest in the group given tadalafil. While corpus cavernosum hyperemia was found to be higher statistically in the experimental groups than in the control group, we found that the severity of hyperemia was less in the group given tadalafil. The corpus cavernosum was found to be statistically more dilated in the experimental groups than in the control group. We determined that hyperoxia status increased the level of SOD and this level decreased with tadalafil administration, which would make a statistical difference.

Urinary Neutrophil Gelatinase-Associated Lipocalin (NGAL) as a Marker of Diabetic Nephropathy in Type 1 Diabetic Patients.

BACKGROUND: Glomerular and tubulointerstitial damage plays a role in renal function failure in diabetic patients. While both serum and urine levels of neutrophil gelatinase-associated lipocalin (NGAL) show significantly increased levels in acute renal pathologies, the NGAL increase in active phase indicates a reversible condition in chronic cases. MATERIALS AND METHODS: 52 type 1 diabetic patients and 30 healthy volunteers participated in the study. The diabetic participants were separated into two groups as follows: a normoalbuminuria group consisting of those with an albumin/creatinine ratio less than 30 mg/g and an albuminuria group consisting of those with an albumin/ creatinine ratio equal or greater than 30 mg/g. Albumin, creatinine and NGAL were measured in all participants. RESULTS: Urinary NGAL median level was 21.1 ng/mL for diabetic patients and 11.9 ng/mL for healthy controls, and the difference between the two groups was statistically significant. When diabetic patients were compared as those with and without albuminuria, the median urinary NGAL levels of normoalbuminuria and albuminuria were 24.7 and 16.1 ng/mL, respectively, but the difference was not statistically significant. Statistically similar results were obtained through evaluation of the ratio of urinary NGAL excretion to creatinine excretion. The NGAL/Cr ratio was significantly higher in diabetic patients than in healthy controls, but no statistically significant difference was found between the diabetic patients with and without albuminuria. CONCLUSIONS: Urinary NGAL excretion in type 1 diabetic patients is found to be increased over a wide range, but it does not correlate with urinary albumin excretion. In this regard, urinary NGAL excretion should not be used as an alternative to microalbuminuria in detecting diabetic nephropathy. The greater amount of NGAL excretion among diabetic patients may be due to diabetic nephropathy with possible tubulointerstitial damage pathologies.

The association between cardiac valvular calcification and fetuin-A levels in kidney transplant recipients.

OBJECTIVES: Low fetuin-A levels in hemodialysis patients can be associated with development of vascular and valvular calcifications. The mechanisms underlying vascular and valvular calcifications are multifactorial. There are a few studies showing the relationship between low fetuin-A levels and valvular calcification after kidney transplantation. We aimed to evaluate the association between serum fetuin-A levels and valvular calcification in kidney transplant recipients. METHODS: The cardiac valvular calcification was assessed by echocardiography in 56 recipients. Patients were divided into two groups as those with (n = 11) and without (n = 45) aortic and/or mitral valve calcification. The extent of valvular calcification was visually assessed according to the standard visual score method: moderately (multiple larger spots) and heavily calcified (extensive thickening and calcification) of all cusps. Serum fetuin-A levels were measured. RESULTS: The demographic features of both groups were comparable. There was no significant difference between regular physical exercise (63.6% vs. 55.6%), obesity (18.2% vs. 17.8%), abdominal obesity (54.5% vs. 46.7%), smoking (0% vs. 13.3%), hypertension (63.6% vs. 68.9%), left ventricular hypertrophy (45.5% vs. 33.3%) and diabetes mellitus (9.1% vs. 20%) ratios in groups with or without valvular calcification, respectively (p > 0.05). Fetuin-A levels of both groups did not differ. Fetuin-A levels positively correlated with serum creatinine (r 0.326, p = 0.014), and negatively correlated with estimated glomerular filtration rate (r - 0.297, p = 0.026). CONCLUSIONS: We could not find a relationship between serum fetuin-A levels and valvular calcification in kidney recipients. In this population, further studies are needed to assess the role of serum fetuin-A in valvular calcification.

A nationwide multicentre study in Turkey for establishing reference intervals of haematological parameters with novel use of a panel of whole blood.

INTRODUCTION: A nationwide multicentre study was conducted to establish well-defined reference intervals (RIs) of haematological parameters for the Turkish population in consideration of sources of variation in reference values (RVs). MATERIALS AND METHODS: K2-EDTA whole blood samples (total of 3363) were collected from 12 laboratories. Sera were also collected for measurements of iron, UIBC, TIBC, and ferritin for use in the latent abnormal values exclusion (LAVE) method. The blood samples were analysed within 2 hours in each laboratory using Cell Dyn and Ruby (Abbott), LH780 (Beckman Coulter), or XT-2000i (Sysmex). A panel of freshly prepared blood from 40 healthy volunteers was measured in common to assess any analyser-dependent bias in the measurements. The SD ratio (SDR) based on ANOVA was used to judge the need for partitioning RVs. RIs were computed by the parametric method with/without applying the LAVE method. RESULTS: Analyser-dependent bias was found for basophils (Bas), MCHC, RDW and MPV from the panel test results and thus those RIs were derived for each manufacturer. RIs were determined from all volunteers' results for WBC, neutrophils, lymphocytes, monocytes, eosinophils, MCV, MCH and platelets. Gender-specific RIs were required for RBC, haemoglobin, haematocrit, iron, UIBC and ferritin. Region-specific RIs were required for RBC, haemoglobin, haematocrit, UIBC, and TIBC. CONCLUSIONS: With the novel use of a freshly prepared blood panel, manufacturer-specific RIs' were derived for Bas, Bas%, MCHC, RDW and MPV. Regional differences in RIs were observed among the 7 regions of Turkey, which may be attributed to nutritional or environmental factors, including altitude.

Adiponectin, leptin, nitric oxide, and C-reactive protein levels in kidney transplant recipients: comparison with the hemodialysis and chronic renal failure.

BACKGROUND: Cardiovascular disease (CVD) is the leading cause of mortality and morbidity in patients with chronic kidney disease (CKD) including kidney transplant recipients (KTR). Secondary lipid metabolism disorders, endothelial dysfunction, and inflammation enhance the risk of CVD development in these patients. The aim of the present study was to investigate the lipid profile, adiponectin, leptin, nitric oxide (NO), and high sensitivity C-reactive protein (hs-CRP) levels in KTR and to compare these parameters with those of the patients with chronic renal failure (CRF), hemodialysis (HD) patients, and healthy controls. METHODS: Serum adiponectin and leptin levels were measured by radioimmunoassay; hs-CRP was determined immunoturbidimetrically. Determination of NO was based on the Griess reaction. RESULTS: Compared with the control group, serum NO and adiponectin levels were significantly higher in the KTR, CRF, and HD groups; hs-CRP levels were significantly higher in the KTR and HD groups; leptin levels were significantly higher in the KTR. In addition, serum NO level was significantly higher in the KTR compared to CRF cases. Adiponectin correlated positively with high density lipoprotein-cholesterol in the control and patient groups. A positive correlation was observed between hs-CRP and NO in the KTR and the patients with CRF. Serum adiponectin levels were inversely correlated with hs-CRP and leptin in the HD group. CONCLUSION: KTR suffer from inflammation and accompanying changes in levels of adipocytokines and NO which contribute to the increased risk of CVD in these patients.

Vitamin B6 supplementation improves oxidative stress and enhances serum paraoxonase/arylesterase activities in streptozotocin-induced diabetic rats.

The purpose of this study was to investigate the effects of vitamin B6 (Vit B6) on oxidant and antioxidant status in streptozotocin-induced diabetic rats. Thirty-two Wistar rats were divided into four groups: control (C), control + Vit B6 group (C + Vit B6), diabetes (D), and diabetes + Vit B6 group (D + Vit B6). Vit B6 (4 mg/kg body weight) was administered in drinking water for 4 weeks after the induction of diabetes. Vitamin B6 reduced serum total cholesterol level in the C + Vit B6 (P < 0.01) and D + Vit B6 (P < 0.05) groups. Plasma and tissue malondialdehyde levels were reduced in the C + Vit B6 and D + Vit B6 groups. Whole blood glutathione peroxidase (GSH-Px) and erythrocyte superoxide dismutase (SOD) activities were higher in the D group (P < 0.05). GSH-Px and SOD activities were increased in C + Vit B6 group while these parameters decreased in the D + Vit B6 group. Paraoxonase and arylesterase activities were decreased in the D group while they were increased in C + Vit B6 and D + Vit B6 groups. The results of present study suggest that vitamin B6 supplementation might be a promising adjunctive agent for improving oxidative stress and metabolic disturbances and for preventing diabetic complications including atherogenesis.

A multicenter nationwide reference intervals study for common biochemical analytes in Turkey using Abbott analyzers.

BACKGROUND: A nationwide multicenter study was organized to establish reference intervals (RIs) in the Turkish population for 25 commonly tested biochemical analytes and to explore sources of variation in reference values, including regionality. METHODS: Blood samples were collected nationwide in 28 laboratories from the seven regions (≥400 samples/region, 3066 in all). The sera were collectively analyzed in Uludag University in Bursa using Abbott reagents and analyzer. Reference materials were used for standardization of test results. After secondary exclusion using the latent abnormal values exclusion method, RIs were derived by a parametric method employing the modified Box-Cox formula and compared with the RIs by the non-parametric method. Three-level nested ANOVA was used to evaluate variations among sexes, ages and regions. Associations between test results and age, body mass index (BMI) and region were determined by multiple regression analysis (MRA). RESULTS: By ANOVA, differences of reference values among seven regions were significant in none of the 25 analytes. Significant sex-related and age-related differences were observed for 10 and seven analytes, respectively. MRA revealed BMI-related changes in results for uric acid, glucose, triglycerides, high-density lipoprotein (HDL)-cholesterol, alanine aminotransferase, and γ-glutamyltransferase. Their RIs were thus derived by applying stricter criteria excluding individuals with BMI >28 kg/m2. Ranges of RIs by non-parametric method were wider than those by parametric method especially for those analytes affected by BMI. CONCLUSIONS: With the lack of regional differences and the well-standardized status of test results, the RIs derived from this nationwide study can be used for the entire Turkish population.

Effects of calcineurin inhibitors on paraoxonase and arylesterase activity after a kidney transplant.

OBJECTIVES: Cardiovascular disease is a common cause of morbidity and mortality in patients with chronic kidney failure, before and after a kidney transplant. Oxidation of lipoproteins that contain apolipoprotein B may contribute to the initiation of atherosclerosis. Paraoxonase may prevent cardiovascular disease. We compared the effects of different calcineurin inhibitors on risk factors for cardiovascular disease in kidney transplant recipients. MATERIALS AND METHODS: In 16 kidney transplant recipients, treatment included tacrolimus in 8 patients and cyclosporine in 8 patients. Hemoglobin, glucose, renal function, lipid parameters, high-sensitivity C-reactive protein, homocysteine, malondialdehyde, paraoxonase activity, and arylesterase activity were measured before transplant and at 1, 6, and 12 months after the transplant. RESULTS: The levels of homocysteine and malondialdehyde did not change significantly in patients who received either tacrolimus or cyclosporine. The high-sensitivity C-reactive protein was decreased (tacrolimus group, 1 mo) and increased (cyclosporine group, 6 and 12 mo) after the kidney transplant. Paraoxonase activity was increased (tacrolimus group, 1 mo). Arylesterase activity was increased (tacrolimus group, 1, 6, and 12 mo; cyclosporine group, 1 and 6 mo). The percentage of change in arylesterase activity was higher at 12 months in the tacrolimus than in the cyclosporine group. CONCLUSIONS: Tacrolimus may be more effective than cyclosporine in improving risk factors for cardiovascular disease after kidney transplant.

Ulva rigida improves carbohydrate metabolism, hyperlipidemia and oxidative stress in streptozotocin-induced diabetic rats.

This study was designed to investigate the effects of Ulva rigida, one of the green algae, on the lipid profile and oxidative-antioxidative systems in streptozotocin-induced diabetic rats. Forty Wistar rats randomly divided into four groups: control (C), control + U. rigida extract (C + URE), diabetes (D) and diabetes + U. rigida extract (D + URE). U. rigida (2%) was administered in drinking water for 5 weeks after the induction of diabetes. U. rigida reduced the blood glucose, serum total cholesterol, triglyceride levels and plasma and tissue malondialdehyde (MDA) levels in the D + URE group. Insulin levels were significantly higher in the D + URE than those of the D group. Serum total cholesterol and tissue MDA levels were reduced in the C + URE group. Whole blood glutathione peroxidase and erythrocyte superoxide dismutase activities were higher in the D and C + URE groups compared with the C group. Paraoxonase and arylesterase activities were lower in the D group while U. rigida increased paraoxonase activities in C + URE and D + URE groups. This is the first study which showed U. rigida has antidiabetic and antihyperlipidemic effects and improves oxidative stress in diabetic rats. We conclude that U. rigida might have a potential use as a protective and/or therapeutic agent in diabetes mellitus.

Effect of repeatedly given CDP-choline on cardiovascular and tissue injury in spinal shock conditions: investigation of the acute phase.

OBJECTIVES: The protective effect of CDP-choline in spinal cord transection and the mediation of its cardiovascular effects were investigated. METHODS: Spinal cords of rats were transected at the T1-T2 levels. CDP-choline (250 mg/kg; intravenous) was administered 2 h and/or 24 h after the injury. KEY FINDINGS: Spinal cord transection caused severe tissue damage, decreased mean arterial pressure, heart rate, plasma adrenaline, and noradrenaline but increased plasma vasopressin levels. Repeated CDP-choline treatment attenuated the degree of tissue injury. Administration of CDP-choline at 2 h after transection transiently increased blood pressure and decreased heart rate, while it produced a small decrease in blood pressure and heart rate when it was given at 24 h. Plasma adrenaline levels were higher in the group where CDP-choline was given repeatedly. Plasma noradrenaline and vasopressin levels did not change additionally after CDP-choline injections in all groups. In order to determine if CDP-choline attenuates the oxidative injury induced by transection, we measured blood superoxide dismutase, glutathione peroxidase activity and malondialdehyde levels. Repeated CDP-choline administration decreased blood superoxide dismutase and glutathione peroxidase activity without any effect on malondialdehyde levels. CONCLUSIONS: Data indicate that repeated intravenous CDP-choline treatment prevents tissue damage in spinal shock conditions in the acute phase. The cardiovascular effects of the drug do not seem to be responsible for this protection but the drug-induced attenuation of the oxidative stress may play a role.

The effects of vitamin E-coated dialysis membranes on serum paraoxonase activity in hemodialysis patients.

BACKGROUND: Hemodialysis patients are exposed to oxidative stress, which can lead to several complications. We therefore sought to evaluate the effect of using vitamin E-coated dialysis membranes for a period of 3 months on serum paraoxonase activity and oxidative stress markers. METHODS: Twenty patients and 25 healthy controls were included in this study. Hemodialysis patients were evaluated before and after 3 months of treatment with vitamin E-coated dialysis membranes. Plasma malondialdehyde (MDA) levels, as well as the oxidizability of red blood cells (RBCs) and apolipoprotein B-containing lipoproteins (expressed as RBC-MDA and DeltaMDA, respectively) were determined in order to investigate the patients' oxidative status. Plasma vitamin E and vitamin C levels, serum total carotenoid levels and paraoxonase activity were measured to investigate the patients' antioxidative defenses. RESULTS: After 3 months of treatment with vitamin E-coated membranes, vitamin E levels were significantly increased and the oxidizability of RBCs was significantly reduced in the hemodialysis patients. However, there were not any differences from baseline in serum paraoxonase activity, plasma MDA levels or the oxidizability of apolipoprotein B-containing lipoproteins in these patients. CONCLUSIONS: Despite promising improvements in vitamin E levels and the oxidizability of RBCs, the results of this study do not support a satisfactory antioxidative effect of vitamin E-coated dialysis membranes. Further studies are needed to identify antioxidative treatments for hemodialysis patients.

Arterial elasticity and plasma levels of adiponectin and leptin in type 2 diabetic patients treated with thiazolidinediones.

BACKGROUND: Thiazolidinediones (TZDs) improve peripheral insulin sensitivity, but the effect on arterial stiffness is less clear. The aim of the present study was to assess the differential effect of pioglitazone or rosiglitazone on arterial stiffness and plasma levels of adiponectin and leptin in patients with type 2 diabetes mellitus. METHODS: Thirty-five type 2 diabetic subjects were randomly assigned to receive pioglitazone (30 mg/day; n = 14), rosiglitazone (4 mg/day; n = 11), or placebo (medical nutrition therapy; n = 10) for 12 weeks. Changes in plasma glucose, glycosylated hemoglobin, insulin resistance (HOMA-IR), total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, triglycerides, adiponectin, and leptin were evaluated at baseline and after 12 weeks. In parallel, large arterial compliance (C1) and small arterial compliance (C2) were measured at baseline and at the end of treatment period. RESULTS: At 12 weeks, the rosiglitazone (P = 0.026) and pioglitazone (P = 0.004) groups had a significant increase from baseline in adiponectin that was not seen in the medical nutrition therapy group. No significant changes in plasma leptin and in C1 and C2 elasticity indexes were observed over the entire study period in any of the treatment groups. CONCLUSIONS: In this study of patients with type 2 diabetes, treatment with TZDs was associated with a significant improvement in adiponectin levels, although no significant effects were seen on leptin levels and arterial elasticity.

Susceptibility of red blood cell lipids to in vitro oxidation and antioxidant status in preeclampsia.

OBJECTIVE: To investigate susceptibility of red blood cell (RBC) lipids to oxidation and antioxidant status in preeclampsia. STUDY DESIGN: Twenty-one women with mild preeclampsia, 21 women with severe preeclampsia, and 20 healthy pregnant women were included in this cross-sectional study. Susceptibility of RBC to oxidative stress was determined by measuring RBC-malondialdehyde levels after incubation with hydrogen peroxide. Vitamins E and C, total carotenoids and erythrocyte superoxide dismutase and glutathione peroxidase (GPx) activities and serum total antioxidant capacity (TAC) were determined spectrophotometrically. One-way analysis of variance and correlation analysis were used for statistical analyses. RESULTS: Compared with the normal pregnant women, susceptibility of RBC to oxidation was enhanced in the mild (p<0.05) and severe (p<0.01) preeclampsia groups, TAC was lower in the mild (p<0.01) and severe (p<0.001) preeclampsia groups. Vitamin C level was decreased in severe preeclampsia and total carotene level was decreased in mild and severe preeclampsia groups (p<0.05). GPx activity was also decreased in the mild (p<0.01) and severe (p<0.05) preeclampsia groups. CONCLUSION: The results of the present study supported the oxidative stress hypothesis of preeclampsia and it is possible that RBC play a role in the pathophysiology of the disease.

High-dose taurine supplementation increases serum paraoxonase and arylesterase activities in experimental hypothyroidism.

1. Hypothyroidism is accompanied by hyperlipidaemia and oxidative stress and is associated with several complications, such as atherosclerosis. Paraoxonase activity has been reported to decrease in several situations associated with atherosclerosis and oxidative stress. In the present study, the effects of different doses of taurine on serum paraoxonase and arylesterase activities, as well as on the serum lipid profile, were investigated in hypothyroid rats. 2. Forty male Sprague-Dawley rats were randomly divided into five groups as follows: Group 1, rats received normal rat chow and tap water; Group 2, rats received standard rat chow + 0.05% propylthiouracil (PTU) in the drinking water; and Groups 3-5, taurine-supplemented PTU groups (standard rat chow + 0.5, 2 or 3% taurine in the drinking water, respectively, in addition to PTU). Paraoxon or phenylacetate were used as substrates to measure paraoxonase and arylesterase activity, respectively. Plasma and tissue malondialdehyde (MDA) levels, indicators of lipid peroxidation, were determined using the thiobarbituric-acid reactive substances method. Serum triglyceride, total cholesterol and high-density lipoprotein-cholesterol (following precipitation with dextran sulphate-magnesium chloride) were determined using enzymatic methods. 3. Serum paraoxonase and arylesterase activities were increased and plasma and tissue MDA levels and serum triglyceride levels were reduced in a dose-dependent manner in taurine-treated hypothyroid rats. Taurine concentrations were positively correlated with enzyme activities and negatively correlated with MDA and triglyceride levels. 4. Further studies are needed to investigate the role of taurine supplementation in hypothyroidism in human subjects.

Paraoxonase activity in glomerulonephritic patients.

BACKGROUND: Cardiovascular disease is the most common cause of morbidity and mortality in patients with chronic renal failure. Glomerulonephritic patients have an increased risk for cardiovascular disease, but its etiology is unclear. It is known that an increase in oxidizability of apolipoprotein B-containing lipoproteins has a key role in the initiation of atherosclerosis, and paraoxonase enzyme activity particularly has a preventive role against atherosclerosis. The aim of the present study was to evaluate the oxidizability of apolipoprotein B-containing lipoproteins, serum, and urinary paraoxonase/arylesterase activities in glomerulonephritis patients who had normal lipid parameters and creatinine levels. METHODS: Thirty-two patients with glomerulonephritis and 22 healthy controls were included in this study. A total of 32 patients (including nine with membranous GN, eight with immunoglobulin A nephropathy, eight with mesangial proliferative GN, five with focal-segmental glomerulosclerosis, one with diffuse proliferative GN, and one with minimal chance disease having biopsy proven GN) were enrolled into the study. We compared serum and urinary paraoxonase, arylesterase, serum lipids, urea, creatinine, hemoglobin, total protein and albumin values between groups. RESULTS: Serum urea, creatinine, total protein, albumin, uric acid, hemoglobin, and lipid parameters were similar in the glomerulonephritis and control groups (p > 0.05). PON1 activity was significantly lower in GN group than controls, but there was no statistically significant difference on arylesterase activity between groups. Oxidizability of apolipoprotein B-containing lipoproteins was significantly higher in GN group than controls. CONCLUSION: Our study shows that the findings of normal serum levels of creatinine, lipids, and proteins increased the oxidizability of apolipoprotein B-containing lipoproteins, and any decrease in PON1 activity in patients diagnosed with GN should be considered important. Hence, the immediate commencement of preventive as well as curative treatment in other to avoid the risk of cardiovascular and renal problems would be a correct approach.

Vanadyl sulfate, taurine, and combined vanadyl sulfate and taurine treatments in diabetic rats: effects on the oxidative and antioxidative systems.

BACKGROUND: Vanadyl sulfate (VS) and taurine are two promising agents in the treatment of diabetes related to their antihyperglycemic, antihyperlipidemic, and hyperinsulinemic effects. Data about the effects of VS on the oxidant-antioxidant system is limited and controversial. However, taurine is a well-documented antioxidant agent and our aim was to investigate the effects of VS, taurine and VS and taurine combination on the oxidative-antioxidative systems in streptozotocin-nicotinamide (STZ-NA) diabetic rats. METHODS: Nicotinamide (230 mg/kg, i.p.) and streptozotocin (65 mg/kg, i.p.) were administered. VS (0.75 mg/mL) and taurine (1%) were added to drinking water for 5 weeks. Rats were divided as control (C), diabetes (D), diabetes+VS (D+VS), diabetes+taurine (D+T), diabetes+VS and taurine (D+VST). Plasma and tissue malondialdehyde (MDA) levels were measured by high-performance liquid chromatography and spectrophotometry, respectively. Paraoxonase and arylesterase activities were measured by spectrophotometric methods and superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities were determined using commercial kits. RESULTS: VS, taurine and VS and taurine combination treatments reduced the enhanced blood glucose, serum total cholesterol and triglyceride, tissue MDA and plasma MDA (except in the D+VS group) levels and increased the reduced serum insulin level, serum paraoxonase and arylesterase activities, GSH-Px activity and SOD activity (except in the D+VS group). CONCLUSIONS: The findings of the present study suggest that VS and taurine exert beneficial effects on the blood glucose and lipid levels in STZ-NA diabetic rats. However, VS might exert prooxidative or antioxidative effects in various components of the body and taurine and VS combination might be an alternative for sole VS administration.

Sialic acid and oxidizability of lipid and proteins and antioxidant status in patients with coronary artery disease.

The aim of this study was to investigate the possible relationship between serum total sialic acid (TSA) concentration, recently shown to be a cardiovascular risk factor, and lipid and protein oxidation and antioxidant status and the severity of coronary artery disease (CAD) according to the obstructive vessel number in patients. The study was carried out on a total of 200 patients (142 men and 58 women) who were hospitalized for elective coronary angiographic evaluation with complaint of typical angina pectoris. According to the results of angiography, 150 patients had angiographically proven CAD (CAD group) and 50 patients had a history suggestive of angina pectoris but normal coronary angiograms (control group). The CAD group was further divided into single-, double- and triple-vessel disease groups according to the number of vessels involved. Lipid parameters were determined by routine laboratory methods. Plasma malondialdehyde (MDA) and vitamin E concentrations were determined by high-performance liquid chromatography. TSA and other oxidant and antioxidant parameters were studied spectrophotometrically. Our results demonstrated significant increases both in TSA levels and in indicators of oxidative stress in the patients with CAD compared with the controls. However, antioxidant parameters were decreased in the patients with CAD. We found strong positive correlations between TSA and plasma MDA, Delta-MDA which represents the degree of oxidative modification of apolipoprotein B-containing lipoproteins, serum protein carbonyls and apolipoprotein B and weak correlations between TSA and low density lipoprotein cholesterol, triacylglycerol, paraoxonase, glutathione peroxidase (GPx), vitamin C and vitamin E. In conclusion, TSA is related to markers of lipid and protein oxidation, paraoxonase and GPx activities, vitamin C and E levels and the severity of CAD.

Oxidation of apolipoprotein B-containing lipoproteins and serum paraoxonase/arylesterase activities in major depressive disorder.

Major depressive disorder (MDD) is blaimed to play a role in the onset of coronary artery disease (CAD). The aim of the present study was to investigate serum paraoxonase/arylesterase activities and oxidation of apolipoprotein B-containing lipoproteins in patients with MDD. Oxidation of lipoproteins plays an important role in atherogenesis and the enzyme paraoxonase, has been shown to prevent lipoprotein oxidation. Furthermore, low paraoxonase activity was suggested to predict CAD. Eighty-six patients who fully met the fourth Diagnostic and Statistical Manual of Mental Disorders criteria for MDD and 36 healthy control subjects were included in the study. Serum paraoxonase and arylesterase activities were determined spectrophotometrically. Malondialdehyde (MDA) levels of apolipoprotein B-containing lipoproteins were determined before (basal) and after incubation with copper-sulphate, that yielded basal- and Delta-MDA values, respectively. Serum paraoxonase/arylesterase activities were significantly reduced in the post-treatment group compared with the pre-treatment group. Basal-MDA (MDA) level was significantly higher in the MDD group compared with the control group. Delta-MDA level of the severe MDD group was significantly higher than that of the control group. There was a positive correlation between the oxidizability of apolipoprotein B-containing lipoproteins and the severity of the disease. Total cholesterol, HDL-cholesterol, LDL-cholesterol, apolipoprotein B levels were significantly higher and apolipoprotein AI levels were significantly lower in the MDD group compared with those of the control group. The findings of the present study suggest that: 1) antidepressant treatment might reduce serum paraoxonase activity/mass; 2) oxidation and oxidizability of apolipoprotein B-containing lipoproteins seem to be increased in MDD.