Amelioration of altered serum,liver, and kidney antioxidant enzymes activities by sodium selenite in alloxan-induced diabetic rats

Background:

The aim of this study was to evaluate the possible protective effect of sodium selenite on serum, liver, and kidney antioxidant enzymes activities in alloxan-induced type 1 diabetic rats.

Methods:

Forty Sprague-Dawley male rats were randomly divided into four groups; Group one as control, Group two as sham-treated with sodium selenite by 1 mg/kg intraperitoneal (i.p.) injections daily, Group three as diabetic untreated, and Group four as diabetic treated with sodium selenite by 1 mg/kg i.p. injections daily .Diabetes was induced in the third and fourth groups by subcutaneous alloxan injections. After eight weeks the animals were euthanized and livers and kidneys were immediately removed and used fresh or kept frozen until analysis. Before the rats were killed blood samples were also collected to measure glutathione peroxidase (GPX) and catalase (CAT) activities in sera.

Results:

Glutathione peroxidase and CAT activities serum, liver, and kidney were all significantly less in the diabetic rats than in the controls. Sodium selenite treatment of the diabetic rats resulted in significant increases in GPX activity in the kidneys and livers, and CAT activity in the sera and livers.

Conclusions:

Our results indicate that sodium selenite might be a potent antioxidant that exerts beneficial effects on both GPX and CAT activities in alloxan-induced type 1 diabetic rats. Key Words: Diabetes, Rat, Sodium selenite, Antioxidant enzymes activity     

Expression Levels of the BDNF Gene and Histone Modifications Around Its Promoters in the Ventral Tegmental Area and Locus Ceruleus of Rats During Forced Abstinence from Morphine

Brain-derived neurotrophic factor (BDNF) plays a role in mediating molecular, cellular, and behavioral adaptations underlying drug addiction. Here, we examined the influence of withdrawal from repeated morphine treatment on the expression of BDNF mRNA in the ventral tegmental area (VTA) and locus coeruleus (LC) of the rat brain. We also studied whether alternations in mRNA levels of BDNF in these tissues are associated with histone modifications around promoters II and III of the BDNF gene. Thus, chromatin immunoprecipitation (CHIP) and quantitative (q)-PCR were employed to assess acetylation of histone H3 at K9/K14 and trimethylation of histone H3 at K9. Results of qRT-PCR showed that levels of BDNF mRNA in both VTA and LC were significantly increased 7 days rather than 2 h or 24 h following the last injection of morphine. Consistently, CHIP and qPCR analysis revealed that on day 7 of morphine abstinence, both VTA and LC levels of histone methylation at BDNF promoters II and III of morphine treated rats were significantly lower than control animals. Morphine withdrawal caused only a significant increase in H3 acetylation at the promoter II in the LC. These data demonstrate the involvement of histone H3 methylation in the regulation of gene expression in the VTA and LC of rats during forced abstinence of morphine.     

Spatial Variations in Vitreous Oxygen Consumption

We investigated the spatial variation of vitreous oxygen consumption in enucleated porcine eyes. A custom made oxygen source was fabricated that could be localized to either the mid or posterior vitreous cavity and steady state vitreous oxygen tension was measured as a function of distance from the source using a commercially available probe. The reaction rate constant of ascorbate oxidation was estimated ex vivo by measuring the change in oxygen tension over time using vitreous harvested from porcine eyes. Vitreous ascorbate from mid and posterior vitreous was measured spectrophotometrically. When the oxygen source was placed in either the mid-vitreous (N = 6) or the posterior vitreous (N = 6), we measured a statistically significant decrease in vitreous oxygen tension as a function of distance from the oxygen source when compared to control experiments without an oxygen source; (p<0.005 for mid-vitreous and p<0.018 for posterior vitreous at all distances). The mid-vitreous oxygen tension change was significantly different from the posterior vitreous oxygen tension change at 2 and 3mm distances from the respective oxygen source (p<0.001). We also found a statistically significant lower concentration of ascorbate in the mid-vitreous as compared to posterior vitreous (p = 0.02). We determined the reaction rate constant, k = 1.61 M^-1s^-1 ± 0.708 M^-1s^-1 (SE), of the oxidation of ascorbate which was modeled following a second order rate equation. Our data demonstrates that vitreous oxygen consumption is higher in the posterior vitreous compared to the mid-vitreous. We also show spatial variations in vitreous ascorbate concentration.     

Monthly fluctuations during the breeding season of sperm density,volume, motility,and composition of seminal and coelomic fluid in broodfish of Persian sturgeon,Acipenser persicus Borodin, 1897

Obtaining knowledge on the gamete quality of certain species is essential for appropriate management and conservation of wild stocks of the species concerned. In the present study, eighteen breeders (nine males and nine females) of Acipenser Persicus Borodin, 1897 were selected for recording breeding season changes in gamete quality in terms of the parameters: spermatozoa motility indices, sperm volume and density, ionic composition and osmolality of seminal and coelomic fluids. Stripping was performed at the beginning of March and during April and May. Results indicated that sperm volume (ml per male) and density (×10⁹ spz ml^?1) decreased towards the end of the spawning season. There was no significant change in osmolality (mOsmol kg^?1) or in the concentrations (as mm ) of sodium, potassium, magnesium or calcium ions in either the seminal or the coelomic fluids during the breeding season. A significant difference in chloride ion concentration in the coelomic fluid was noted at different times during the spawning season. The percentage of motile spermatozoa at 45 s post‐activation was not significantly different for samples taken at different dates, but the maximum duration of spermatozoa movement, at 15 s post‐activation, was observed in March. This value decreased significantly towards the end of the reproductive season. In conclusion, changes observed in A. persicus sperm parameters during the breeding season suggest an association between such changes and the sperm aging processes.     

The effect of Bacillus subtilis producing Surfactin in ROS production and transformation efficiency of tobacco cells

Surfactin secreted by bacilli has biological functions in plant. Surfactin C14 and C15 have the highest effect on inducing hydrogen peroxide species release in the plant. Surfactin production in the two Bacillus strains ACCT21332 and FKR3 were analysed by HPLC and the phytotoxicity of the Bacilli-derived surfactins was determined in Tobacco cell culture. Surfactin C14 and C15 were detected in ACCT21332 but not in FKR3 strain. Extracellular hydrogen peroxide produced by tobacco cell culture cells exposed to ATCC21332 and FKR3 strains increased compared to untreated ones. The Agrobacterium mediated transformation rate of tobacco cells drops from 4% transformed cells to 0.8 and 1.2% when pretreated with ATCC21332 or FKR3 strain, respectively. The strong drop in transformation rate of plant cell culture after FKR3 strain pre-treatment indicates that Surfactin C14 and C15 are not the major or the only cause in protecting plant cells from Agrobacterial infection and transformation.     

Dynamin-Related Protein 1-Dependent Mitochondrial Fission Changes in the Dorsal Vagal Complex Regulate Insulin Action

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Betaine Down Regulates Apelin Gene Expression in Cardiac and Adipose Tissues of Insulin Resistant Diabetic Rats Fed by High-Calorie Diet

Apelin is a newly discovered peptide that its serum level increases in diabetic patients with cardiovascular dysfunction. Recent studies indicate the beneficial actions of betaine in reducing the cardiovascular and metabolic complications, however data related to its effect on adipocytokine expression is limited. The aim of this study was to evaluate the effect of betaine supplementation on Apelin gene expression in cardiac muscle and adipose tissue of insulin resistance, diabetic rats fed by a high calorie diet. To induce insulin resistance rats were fed with high fat/high carbohydrate diet for five weeks and then 30 mg/kg STZ was injected intraperitoneally. After confirming of diabetes incidence (serum glucose above 7.5 mmol/l) the animals were treated with 1 % betaine in drinking water for 28 days. At days 14 and 28 after treatment, animals were euthanized and Apelin gene expression was evaluated by real time PCR and western blot in heart and adipose tissues. Serum levels of insulin, Apelin and glucose and HOMA–IR were also measured. Our results showed that feeding of rats by a high calorie diets caused insulin resistance, which was manifested by elevated plasma insulin, glucose and Apelin levels and also HOMA–IR. Apelin gene expression in heart and adipose tissues were significantly increased simultaneously with the progression of diabetes. Betaine supplementation decreased serum Apelin and down regulated Apelin expression in adipose tissue and cardiac muscle, particularly at day 28 of treatment. We concluded that betaine might improve metabolic and cardiovascular complications in diabetic patients by regulation of Apelin expression and secretion.     

Enzyme-Linked Immunosorbent Spot (ELISpot) monitoring of cytokine-producing cells for the prediction of acute rejection in renal transplant patients

The purpose of this study was to evaluate T-cell immunity markers using serial post-transplantation monitoring of cytokine-producing cells during the first post-transplant months for the prediction of acute rejection and potentially chronic rejection of kidney allograft. We followed 57 kidney allograft recipients for meanly 3 years post-transplantation. Blood samples were collected pre-transplant, 2, 4 and 12 weeks post-transplant. The frequencies of IL-10-, IL-17- and IFN-γ-producing cells were determined in all time-points using ELISPOT assay. The results of ELISpot monitoring and levels of IL-23 and TGF-β were compared between recipients with acute (n = 12) or chronic rejection episodes and patients with stable graft function (n = 45). In all post-transplant time-points, significantly high frequencies of IFN-γ- and IL-17-producing cells and low frequency of IL-10-producing cells were observed in rejection group versus patients with stable graft function (P<0.0001). TheROCcurve analysis for determining the reliability of cytokine-producing cells for the prediction of acute rejection revealed that AUC was 0.046 for IL-10 (P<0.001), 0.927 for IL-17 (P<0.001) and 0.929 for INF-γ-producing cells (P<0.001). Our results indicate that analyzing the frequencies of INF-γ/IL-10/IL-17-producing cells may define a reliable panel for the prediction of acute rejection within the first post-transplant year which could also be applicable for the prediction of chronic rejection episodes.