Antioxidant Paraoxonase Research Articles

Oxidative DNA Damage Is Increased in Living Kidney Donors

BackgroundLong-term consequences of donor nephrectomy might be reduced kidney function, increased risk for cardiovascular disease, and impaired quality of life. The purpose of the current cross-sectional study was to evaluate the relationship between clinical, laboratory, and donation-specific outcomes of living kidney donors and systemic oxidative DNA damage. MethodsWe conducted a cross-sectional study and assessed retrospectively pre- and postdonation data from 60 donors who donated between 2010 and 2015. Plasma malondialdehyde levels and 8-hydroxy-2′-deoxyguanosine/deoxyguanosine ratio (8-OHdG/dG ratio) were determined as oxidative stress markers. Catalase, carbonic anhydrase, and paraoxonase (PON) activities were measured as antioxidants. ResultsApproximately 3 years after donation, the hypertensive donor ratio was 12%, and 11% of the donors had glomerular filtration rate <60 mL/min/1.73 m2. Mean serum urea (P = .001) and serum creatinine levels (P = .001) were increased; creatinine clearance level (126.2 ± 35.5 vs 94.6 ± 26.8, P = .001) was decreased in the postdonation period. There was a significant positive correlation between predonation serum urea and 8-0HdG/dG ratio (r = 0.338, P = .016) and predonation serum creatinine and 8-0HdG/dG ratio (r = 0.442, P = .001), while there was a significant negative correlation between serum creatinine and PON activity (r = −0.545, P < .001). ConclusionOur data have demonstrated that kidney donors exhibit increased oxidative DNA damage and decreased antioxidant activity. We propose that predonation serum creatinine is positively correlated with 8-0HdG/dG ratio and negatively correlated with antioxidant PON activity. This is the first study to demonstrate that plasma oxidative DNA damage increases in healthy kidney donors.

HYDROALCOHOLIC EXTRACT OF MATRICARIA CHAMOMILLA LINN. AMELIORATES LIPIDS, LIPOPROTEINS, AND PARAOXONASE IN ISOPROTERENOL-INDUCED MYOCARDIAL INFARCTION IN WISTAR RATS

Objective: The objective of this study was to evaluate the effect of the hydroalcoholic extract of Matricaria Chamomilla Linn. (CHAE) on lipids, lipoproteins, and antioxidants activity in isoproterenol (ISO)-induced myocardial infarcted rats.&#x0D; Methods: ISO (85 mg/kg, s.c.)-induced myocardial infarction for 2 consecutive days at an interval of 24 h. Rats were pretreated with CHAE (100 and 200 mg/kg, oral) for a period of 20 days and ISO was injected on 21 and 22 days at 24 h intervals and after 24 h, blood was collected through retro-orbital plexus for the estimation of lipids, lipoproteins, and antioxidants assay.&#x0D; Results: In the present study, ISO caused a significant increase in the concentration of total cholesterol, triglycerides, low-density lipoprotein cholesterol (LDL-C), very LDL-C, and lipid peroxidation whereas a significant decrease in the concentration of high-density lipoprotein-C. ISO administration also significantly decreased the activities of paraoxonase (PON) enzyme. Oral pre-treatment of CHAE at doses of 100 and 200 mg/kg body weight (bw) for 20 days challenged with a concurrent injection of ISO (85 mg/kg bw) on 21 and 22 days significantly attenuated these alterations and restored the levels of lipids and lipoproteins. In addition, CHAE significantly elevated the serum antioxidants enzyme PON and catalase (CAT).&#x0D; Conclusion: The report revealed that pre-treatment with CHAE ameliorated lipid and lipoprotein and increased the antioxidant PON and CAT activity and decreased LPO level in ISO-treated male albino Wistar rats.

Polymorphisms in the anti-oxidant paraoxonase-1 (PON1) gene associated with fertility of postpartum dairy cows

Paraoxonase 1 (PON1) is a negative acute phase plasma protein synthesized by the liver that has anti-oxidant activity. The aim of this study was to evaluate the association of single nucleotide polymorphisms (SNPs) in the PON1 promoter region with plasma PON1 activity and fertility in Holstein dairy cows. Sixty-eighty Holstein cows were used in this initial investigative study. Blood samples were collected weekly beginning 28 days prior to expected calving, twice weekly in week 1 and 2 postpartum, and then once weekly through 6 weeks postpartum for plasma PON1 activity analysis. Cows were synchronized for ovulation and timed AI at 63–70 DIM using an Ovsynch program. Pregnancy diagnosis was confirmed by rectal palpation and reproductive performance data was recorded until 210 DIM. DNA was extracted from blood of each cow and a fragment of proximal PON1 gene promoter was sequenced. Seven single nucleotide polymorphisms (SNPs) were identified in the promoter region of the PON1 gene at positions −22, −105, −176, −221, −392, −611 and −676, six of which were significantly associated with plasma PON1 activity level. The SNPs −221 and −392 were significantly associated with both plasma PON1 activity and the calving to conception interval (P < 0.05) with no significant effect on calving to first ovulation interval. In conclusion, the genotypes associated with higher plasma PON1 activity in SNP locations −221 and −392 were also associated with a reduced calving to conception interval in this study set of cows. These SNPs may provide novel genetic markers for improved fertility in future larger studies in dairy cows.

A11974 SNX1 Loss Manifests with Increased Oxidative Stress and Hypertension

Objectives: Acute depletion of renal sorting nexin 1 (SNX1) results in blunted natriuretic response and hypertension in mice due to impaired dopamine D5 receptor (D5R) activity. We elucidated the molecular mechanisms for these phenotypes in Snx1−/− mice, which have a congenital absence of SNX1. Methods: Basal reactive oxygen species (ROS) levels, NOX activity, and blood pressure of Snx1−/− mice and the activity of cAMP and sodium transport of renal proximal tubule cells from hypertensive (HT) were measured. Results: These mice had increased renal expression of AT1R, NADPH oxidase (NOX) components, D5R, sodium-chloride cotransporter, and the antioxidant paraoxonase 2. Basal reactive oxygen species (ROS) levels, NOX activity, and blood pressure were also markedly higher in Snx1−/− mice, which were normalized by apocynin, a drug that prevents NOX assembly. HT renal proximal tubule cells from Caucasian males have deficient SNX1, impaired D5R endocytosis, and increased ROS compared with cells from normotensive (NT) male subjects. siRNA - mediated depletion of SNX1 in NT cells led to a blunting of agonist-induced increase in cAMP production and decrease in sodium transport, while gene rescue via over-expression of SNX1 in HT cells normalized the D5R agonist-mediated stimulation of cAMP production and inhibition of sodium transport. Three of the 12 single nucleotide polymorphisms interrogated for the SNX1 gene associated with poor blood pressure response to thiazide among hypertensive blacks. Conclusion: Our data demonstrate a new paradigm for the development of hypertension.

Terminalia pallida fruit ethanolic extract ameliorates lipids, lipoproteins, lipid metabolism marker enzymes and paraoxonase in isoproterenol-induced myocardial infarcted rats.

The present study aimed to evaluate the effect of Terminalia pallida fruit ethanolic extract (TpFE) on lipids, lipoproteins, lipid metabolism marker enzymes and paraoxonase (PON) in isoproterenol (ISO)-induced myocardial infarcted rats. PON is an excellent serum antioxidant enzyme which involves in the protection of low density lipoprotein cholesterol (LDL-C) from the process of oxidation for the prevention of cardiovascular diseases. ISO caused a significant increase in the concentration of total cholesterol, triglycerides, LDL-C, very low density lipoprotein cholesterol and lipid peroxidation whereas significant decrease in the concentration of high density lipoprotein cholesterol. ISO administration also significantly decreased the activities of lecithin cholesterol acyl transferase, PON and lipoprotein lipase whereas significantly increased the activity of 3-hydroxy-3-methylglutaryl-coenzyme-A reductase. Oral pretreatment of TpFE at doses 100, 300 and 500 mg/kg body weight (bw) and gallic acid (15 mg/kg bw) for 30 days challenged with concurrent injection of ISO (85 mg/kg bw) on 29th and 30th day significantly attenuated these alterations and restored the levels of lipids, lipoproteins and the activities of lipid metabolizing enzymes. Also TpFE significantly elevated the serum antioxidant enzyme PON. This is the first report revealed that pretreatment with TPFE ameliorated lipid metabolic marker enzymes and increased the antioxidant PON in ISO treated male albino Wistar rats.

P46 Acaí pulp (Euterpe oleraceae Martius) consumption improves lipidic peroxidation markers in healthy women

Cardiovascular diseases (CVD) represent one of the main causes of morbidity and mortality in the world. Acai is a typical Brazilian fruit that presents in its composition phenolic compounds with high antioxidant power. These compounds appear to have an effect on lipid oxidation products, such as the LDL-c described as a determinant factor for the development of atherosclerosis. Paraoxonase, an enzyme present in the HDL molecule, is able to prevent oxidation of LDL and can be modulated by dietary factors. Given the high antioxidant potential of acai, the present study evaluated the effect of the consumption of healthy acai pulp on lipid oxidation markers in healthy women. A nutritional intervention study was carried out, composed of 48 volunteers who were categorized according to the atherogenic index plasma (AIP). The volunteers were instructed to consume 200 g/day of acai pulp for one month. Before and after the intervention, anthropometry was performed and blood samples collected for determination of the concentration of malondialdehyde (MDA), oxidized LDL (oxLDL), total antioxidant capacity (TAC) and paraoxonase activity. At the end of the intervention, the group of women with low risk of developing CVD showed a reduction in oxLDL (62%) and MDA (72%) concentrations and an increase in TAC (14%). The concentration of oxLDL and MDA were reduced after the intervention, (53% e 64%, respectively) and an increase of paraoxonase activity (25%) in the high-risk group. These results propose a beneficial effect of acai on molecules involved in the process of lipid peroxidation and as result, atherosclerosis.

Paraoxonase and Arylesterase Levels in Behcet's Disease and Their Relations with the Disease Activity.

The aim of this study was to determine the paraoxonase (PON) and arylesterase (ARE) enzyme activity levels in Behcet's disease (BD) and to investigate whether they are associated with the disease activity. Twenty-six patients (study group) with active BD and 28 healthy controls (control group) were included in this study. While the patients who had at least one of the symptoms related to genital ulcer, skin lesions, active uveitis, arthritis, thrombophlebitis, or central nervous system involvement in addition to oral ulcers were considered as the active group, the patients who did not show clinical symptoms in the last one month due to the medical treatment were considered as the inactive group in the clinical evaluation of patients with BD. The PON and ARE levels were found to be significantly lower in the study group than the control group (p<0.05). The PON levels of the active and inactive groups were 96.23±57.84 and 112.2±65.14, respectively. The ARE levels of the active and inactive groups were 30.49±5.81 and 30.85±6.40, respectively. No significant correlations were found between clinical findings and the activity levels of PON and ARE in the active patient group (p>0.05). The activities of the antioxidant PON and ARE enzymes are reduced in BD. Therefore, it may be useful to add antioxidant therapy to the conventional treatment of the disease.

Açai (Euterpe oleracea Mart.) dietary intake affects plasma lipids, apolipoproteins, cholesteryl ester transfer to high-density lipoprotein and redox metabolism: A prospective study in women

The açai fruit (Euterpe oleracea Martius), which is native to the Brazilian Amazon region, was shown to have high polyphenols and MUFA contents. In this study, we aimed to assess the effects of açai consumption on plasma lipids, apolipoproteins, the transfer of lipids to HDL (which is a relevant HDL function), and some biomarkers of redox metabolism. Forty healthy volunteer women aged 24±3 years consumed 200g of açai pulp/day for 4 weeks; their clinical variables and blood sample were obtained before and after this period. Açai pulp consumption did not alter anthropometric parameters, systemic arterial pressure, glucose, insulin and total, LDL and HDL cholesterol, triglycerides and apolipoprotein (apo) B, but it did increase the concentration of apo A-I. Açai consumption decreased the ROS, ox-LDL and malondialdehyde while increasing the activity of antioxidative paraoxonase 1. Overall, the total antioxidant capacity (TAC) was increased. Regarding the transfer of plasma lipids to HDL, açai consumption increased the transfer of cholesteryl esters (p=0.0043) to HDL. Unesterified cholesterol, phospholipids and triglyceride transfers were unaffected. The increase in apo A-I and the cholesteryl ester transfer to HDL after the açai intake period suggests that an improvement in the metabolism of this lipoprotein occurred, and it is well known that HDL is protective against atherosclerosis. Another important finding was the general improvement of the anti-oxidant defences elicited by açai consumption. Our data indicate that açai has favourable actions on plasma HDL metabolism and anti-oxidant defence; therefore açai could have a beneficial overall role against atherosclerosis, and it is a consistently good candidate to consider as a functional food.

Abstract 97: Increased Plasma Level of ApoCIII-rich Electronegative HDL May Contribute to Cognitive Impairment in Alzheimer’s Disease

Background: High-density lipoprotein (HDL), the only lipoprotein class that can cross the blood brain barrier bidirectionally, is positively associated with cognitive functions. To delineate HDL’s role in Alzhenimer’s disease (AD), we analyzed the chemical properties of plasma HDL from AD and healthy normal adult (control) subjects. Methods and results: By using anion-exchange chromatography, we divided HDL into 5 increasingly electronegative subfractions, H1-H5. Compared to the control cohort (4.24±3.22%; n=20), HDL from AD patients (23.48±17.83%; n=30) had a 5.5-fold increase of H5 ( P &lt;0.001; Figure ), accompanied by a decreased protein/lipid ratio attributed to a significant reduction of albumin essential for prevention of amyloid beta (Aβ) aggregation. As determined by LC/MS E and ProteinLynx Global SERVER (PLGS), AD-HDL was had a rich content of apolipoprotein (apo)CIII, but diminished amounts of sphingosine-1-phosphate (S1P)-associated apoM and antioxidative paraoxonase 1 (PON1). Exposure of murine RAW 264.7 macrophages to H5 induced vibrant expression of ganglioside GM1 in colocalization with apoCIII on lipid rafts, alongside a concomitant increase of TNF-α detectable in the cultured medium ( Figure ). LC/MS E examination localized posttranslational oxidation exclusively in ApoA1 residues of H5 in AD-HDL, which exhibited a compromised cholesterol efflux capacity. Conclusions: Plasma HDL from AD patients has a high proportion of H5, an apoCIII-rich electronegative HDL subfraction. The associated reduction in functional (albumin, S1P, apoM) and increase in proinflammatory (apoCIII, PON1, TNF-α) components may favor Aβ assembly and neuroinflammation. Additionally, a compromised cholesterol-efflux capacity of AD-HDL may also contribute to vascular cognitive impairment.

High morning blood pressure surge is associated with oxidative stress and paraoxonase 1 activity in newly diagnosed hypertensive patients

ABSTRACTBackground: Both oxidative stress and morning surge (MS) of blood pressure (BP) were found to be closely related with cardiovascular and cerebrovascular diseases. We investigated the association between MS of BP and oxidative stress in newly diagnosed hypertensive patients. Methods: We prospectively included 237 newly diagnosed hypertensive patients in the present study (mean age: 51.6 ± 11.7 years). The patients were classified according to the extent of the sleep-through surge as follows: the top decile of sleep-through surge (>47.2 mmHg, n = 27; EMShigh group), versus all others (n = 210, EMSlow group). Total antioxidant capacity (TAC) and total oxidant status (TOS) levels were determined by using an automated measurement method. The oxidative stress index (OSI) was calculated as the ratio of TOS to TAC. Serum paraoxonase 1 (PON-1) activity was measured spectrophotometrically. Results: Patients in EMShigh group were found to have higher hs-CRP, TOS, and OSI values and lower TAC and PON-1 values (p < 0.01, for all). MS of BP was associated with hs-CRP, PON-1, TOS, TAC, and OSI levels in bivariate analysis. Multivariate linear regression analysis showed that MS of BP was significantly associated with PON-1(β = −0.206, p < 0.001), OSI (β = 0.602, p < 0.001) and hs-CRP (β = 0.210, p < 0.001). Conclusion: Present study shows that OSI is increased and antioxidant PON-1 activity is decreased in patients with enhanced MS of BP. There is a close association between high MS of BP and oxidative stress markers in newly diagnosed hypertensive patients.

Total antioxidant, total oxidant and serum paraoxonase levels according to lipid administration method in parenterally fed premature infants

Objective: The aim of our study was to determine whether lipid solutions delivered separately or in mixture with total parenteral nutrition (TPN) solutions effect the balance between oxidant and antioxidant levels in premature infants.Methods: A total of 60 preterm newborns who were delivered at their 30–34 gestational weeks and received TPN were included in the study. Premature newborns were randomized into two groups based on the delivery method of the lipid solution, separately (Group 1) or in mixture with TPN solutions (Group 2). Total antioxidant status (TAS), total oxidant status (TOS) and paraoxonase (PON-1) levels were analyzed in both blood samples, and oxidative stress index (OSI) was also calculated.Results: Thirty cases from both groups were included in the study. Statistically significant decrease in the level of TAS and increase in the level of PON-1 were detected at 72 h of TPN therapy in both groups (p < 0.05). Statistically significant decrease in both TOS and OSI levels were observed in Group 2 (p < 0.05). In association with these findings, any statistically significant intergroup difference was not detected in both parameters regarding oxidant balance (p > 0.05).Conclusion: Our study showed that according to lipid administration method any difference for oxidant–antioxidant balance was not detected.

Paraoxonase 1 (PON1) and pomegranate influence circadian gene expression and period length

ABSTRACTThe circadian timing system regulates key aspects of mammalian physiology. Here, we analyzed the effect of the endogenous antioxidant paraoxonase 1 (PON1), a high-density lipoprotein-associated lipolactonase that hydrolyses lipid peroxides and attenuates atherogenesis, on circadian gene expression in C57BL/6J and PON1KO mice fed a normal chow diet or a high-fat diet (HFD). Expression levels of core-clock transcripts Nr1d1, Per2, Cry2 and Bmal1 were altered in skeletal muscle in PON1-deficient mice in response to HFD. These findings were supported by circadian bioluminescence reporter assessments in mouse C2C12 and human primary myotubes, synchronized in vitro, where administration of PON1 or pomegranate juice modulated circadian period length.

The Protective Effects of Caffeic Acid Phenethyl Ester on Acetylsalicylic Acid-induced Lung Injury in Rats

ABSTRACTAim: We aimed to investigate the protective effect of caffeic acid phenethyl ester (CAPE) on acetylsalicylic acid (ASA)-induced lung damage in rats in the present study. Methods: A total of 40 rats were randomly divided into five groups, with eight rats in each group—group 1: control, not receiving any medication; group 2: ASA (50 mg/kg/day); group 3: ASA (50 mg/kg/day) plus CAPE (20 μg/kg/day); group 4: ASA (100 mg/kg/day); and group 5: ASA (100 mg/kg/day) plus CAPE (20 μg/kg/day). ASA and CAPE were given via orogastric gavage for 5 days. The total oxidant status (TOS), total antioxidant capacity (TAC), oxidant stress index (OSI), and paraoxonase-1 (PON-1) activity of the blood samples and lung tissues were determined. Histopathological examinations of the lung tissues were performed by using light microscopic methods. Results: CAPE treatment significantly increased antioxidant PON-1 level both in the lung tissue and plasma (p < .05). Plasma antioxidant marker (TAC, PON-1) levels significantly increased and oxidant marker (TOS, OSI) levels significantly decreased in CAPE-treated rats (groups 3,5) compared to ASA given no-CAPE groups (group 2,4) (p < .05). Treatment with CAPE improved pulmonary interstitial inflammation and eosinophil accumulation due to ASA histopathologically. Conclusion: Eosinophil-rich inflammation and oxidative stress play important roles in ASA-induced lung toxicity, and CAPE may protect against ASA-induced lung toxicity by reduction of oxidative damage and inflammation in rats.

Dietary intake of cod and scallop reduces atherosclerotic burden in female apolipoprotein E-deficient mice fed a Western-type high fat diet for 13 weeks.

BackgroundIt is now increasingly recognized that the beneficial effects of seafood consumption is not limited to lipids and fatty acid, but that the protein part, i.e., peptides and amino acids, together with vitamins and even unknown bioactive constituents also are important for disease prevention. This study was designed to evaluate the putative anti-atherogenic effects of different protein sources (a lean seafood and a nonseafood) in apolipoprotein E-deficient (apoE−/−) mice.MethodsTwenty-four 5-week-old female apoE−/− mice were fed Western type diets containing chicken or a combination of cod and scallops as dietary protein sources for 13 weeks. Atherosclerotic plaque burden, weight, serum levels of leptin, glucose and LDL cholesterol as well as gene expressions from liver and heart were evaluated. Statistical analyses were performed using SPSS. Differences between the variables were evaluated using independent t-test or Mann–Whitney U test for normally and non-normally distributed variables, respectively. Normality was defined by the Shapiro-Wilk test.ResultsThe mice fed cod-scallop had a 24 % (p < 0.05) reduced total aorta atherosclerotic plaque burden compared to the chicken fed group, whereas the reduction in plaque in the less lesion prone thoracic and abdominal parts of the descending aorta were 46 % (p < 0.05) and 56 % (p < 0.05), respectively. In addition, mice fed cod-scallop gained less weight, and had lower serum levels of leptin, glucose and LDL cholesterol, compared to those fed chicken. Analysis of expression of the genes from liver and heart showed that hepatic endogenous antioxidant paraoxonase 2 (Pon2 gene) and the vascular cell adhesion molecule VCAM-1 (Vcam1 gene) were down regulated in mice fed cod-scallop compared to mice fed chicken.ConclusionThe present study revealed a metabolic beneficial effect of lean seafood compared to chicken, as atherosclerotic plaque burden, serum glucose, leptin and LDL cholesterol levels were reduced in mice fed cod-scallop.Electronic supplementary materialThe online version of this article (doi:10.1186/s12986-016-0068-z) contains supplementary material, which is available to authorized users.

Analyzing the Correlation of Serum Iron Parameters with Paraoxanase, Arylesterase and Oxidative Stress Markers in Stem Cell Transplantation Patients

Background: Hematopoietic Stem Cell Transplantation (HSCT) itself is associated with morbidity and mortality, and impaired iron metabolism might have an impact on these complications. Iron, ferritin overload in tissues and systemic circulation, is importantly thought that (to) increase the oxidative stress. Methods: In patients and controls serum iron, iron binding capacity and ferritin levels were measured. Antioxidant enzymes, Catalase (CAT), Glutathione peroxidase (GPx), Paraoxonase (PON), Arylesterase (ARE), and Glutathione-s Transferase (GST) activities were measured in the serum. These parameters and enzymes in relevance to malondialdehyde (MDA) were evaluated. Results: Serum MDA levels were significantly increased in the autologous group compared with the control group (p 0.05). Serum PON activity levels in autologous were found to be low when compared with the control group (p < 0.05). In terms of serum iron levels, statistically significant difference were found between allogeneic, autologous and the control group (p < 0.05). Serum ferritin levels were found high in allogeneic and autologous groups than the control group (p < 0.05). According to Spearman’s correlation analysis, between serum MDA level and GPx activity in serum, a negative correlation was found. Between serum MDA and serum GST, and between serum PON activity and serum ARE activity were found a positive correlation. Conlusions: Serum and tissues ferritin overload and the decrease in antioxidative enzymes activity levels may be harmful to body, causing some types of blood cancer diseases.

Measurement of activity and concentration of paraoxonase 1 (PON-1) in seminal plasma and identification of PON-2 in the sperm of boar ejaculates.

This study revealed and characterised the presence of the antioxidant enzymes paraoxonase (PON) type 1 (PON-1, extracellular) and type 2 (PON-2, intracellular) in boar semen. To evaluate PON-1, an entire ejaculate from each of ten boars was collected and the seminal plasma was harvested after double centrifugation (1,500g for 10 min). Seminal plasma was analysed for concentration as well as enzymatic activity of PON-1 and total cholesterol levels. Seminal-plasma PON-1 concentration ranged from 0.961 to 1.670 ng/ml while its enzymatic activity ranged from 0.056 to 0.400 IU/ml, which represent individual variance. Seminal-plasma PON-1 concentration and enzymatic activity were negatively correlated (r = -0.763; P < 0.01). The activity of seminal-plasma PON-1 negatively correlated with ejaculate volume (r = -0.726, P < 0.05), but positively correlated with sperm concentration (r = 0.654, P < 0.05). Total seminal-plasma cholesterol concentration positively correlated with PON-1 activity (r = 0.773; P < 0.01), but negatively correlated with PON-1 concentration (r = -0.709; P < 0.05). The presence of intracellular PON-2 was determined via immunocytochemistry in spermatozoa derived from artificial insemination. PON-2 localised to the post-acrosomal area of the sperm head and principal piece of the tail in membrane-intact spermatozoa. In summary, PON is present in boar semen, with PON-1 at low levels in seminal plasma and PON-2 within the spermatozoa. Further studies are needed to characterise the relationship between antioxidant PONs with sperm and other seminal-plasma parameters.

272 EFFECT OF DIETARY RESTRICTION ON SPERM CHARACTERISTICS AND OXIDATIVE STATUS ON TESTICULAR TISSUE IN YOUNG RATS EXPOSED TO LONG-TERM HEAT STRESS

The objective was to evaluate effects of dietary restriction on oxidative status and sperm parameters in rats exposed to long-term heat stress. Forty healthy Sprague-Dawley rats (2.5 months old) were equally allocated into 4 groups (with respect to diet and temperature): room temperature (22°C)-ad libitum; room temperature-dietary restriction (40%); high temperature (38°C)-ad libitum; and high temperature-dietary restriction. At the end of the 9th week, some oxidants (lipid hydroperoxide, total oxidant status, oxidative stress index) and some antioxidants (total antioxidant status, sulfhydryl groups, ceruloplasmin, paraoxonase and arylesterase activities) were measured in testicular tissues. In addition, concentration, motility, volume, abnormal sperm count, acrosome and membrane integrity of epididymal sperm were also evaluated. All data were analysed by 2-way ANOVA (P &lt; 0.05). High temperature did not significantly affect most oxidative and antioxidative parameters (except for sulfhydryl groups and ceruloplasmin), yet it impaired all sperm values. Neither sperm values nor oxidative status, with the exception of sulfhydryl groups, ceruloplasmin and arylesterase in the testis tissue, were significantly affected by dietary restriction. We concluded that long-term heat stress did not significantly affect testicular oxidative status in young rats, although sperm were sensitive to heat stress. Furthermore, dietary restriction failed to improve sperm quality and oxidative status, except some individual antioxidant parameters in young rats exposed to long-term heat stress.

Abstract 573: Uncovering the Molecular Mechanisms Underlying the Hypertension in Snx1 Knockout Mice

We have reported that sorting nexin 1 (SNX1) is crucial for renal dopamine D 5 receptor (D 5 R) trafficking, signal transduction, and function in human renal epithelial cells and in C57Bl/6J and BALB/cJ mice, as shown by the development of hypertension and impaired natriuretic response to agonist stimulation after an acute SNX1 depletion in the kidney. Thus, we elucidated the renal molecular mechanisms for these phenotypes in Snx1 -/- mice, which have congenital absence of SNX1. These mice have increased expression of glycosylated AT 1 R (123.8±2.1 vs . 100±2.0% in wild-type littermates, P&lt;0.05, Student’s t -test, n=5/group), a receptor with pro-oxidant and hypertensinogenic effects. We next determined the expression profiles of the components of the NADPH oxidase (NOX), an enzyme complex that is a major source of reactive oxygen species (ROS). We found an increased expression of renal NOX1 (153.4±12.2% vs . 100±4.1%, P&lt;0.05), NOX2 or gp91 phox (129.9±5.5% vs . 100±7.7%, P&lt;0.05), and p47 phox (118.2±2.7% vs . 100±5.0%, P&lt;0.05), suggesting increased oxidative stress in these mice. Interestingly, the Snx1 null mice have elevated renal D 5 R (142.9±4.7% vs . 100±6.8%, P&lt;0.05) and D 3 R (134.3±5.3% vs . 100 ± 1.6%, P&lt;0.05), receptors with anti-oxidant activity, as well as the antioxidant paraoxonase 2, perhaps as compensatory mechanisms; the loss of SNX1 impairs the function of D 5 R. To corroborate our findings, we treated the Snx1 -/- mice and controls with a 10-day renal infusion of apocynin, a drug that blocks NOX assembly by preventing p47 phox translocation to NOX2. Apocynin treatment resulted in the amelioration of systolic blood pressure (SBP) in Snx1 -/- mice (131.3±4.8 mm Hg to 105.7±1 mm Hg, P&lt;0.05). There was no difference in the SBP with vehicle treatment in both strains, or with apocynin in control mice. Basal NOX activity was higher in Snx1 -/- mice (169±12.8 units/mg protein/min vs . 100±13.3 in controls, P&lt;0.05), which was normalized by apocynin (99.4±16.5), while basal ROS levels were 2-fold higher in the Snx1 -/- mice (218.6±7.7 units/mg protein vs . 100±17.9, P&lt;0.05), which was also normalized by apocynin (125.8±20.4). Our data indicate that the hypertension in Snx1 -/- mice is due to impaired D 5 R activity, higher NOX expression and activity, and increased AT 1 R.

Effect of vitamins, probiotics and protein level on semen traits and seminal plasma biochemical parameters of post-moult male broiler breeders

1. A study was designed to investigate the comparative effect of supplementary vitamin E, vitamin C, probiotics and dietary crude protein concentration on semen traits and seminal plasma biochemical parameters in male broiler breeders after Zn-induced moulting. 2. A total of 180 male broiler breeders were induced to moult at 65 weeks of age by mixing ZnO in diet at the rate 3000 mg/kg of feed. After moulting, the males were divided into six groups that were given feed supplemented with: vitamin C (500 IU/kg), vitamin E (100 IU/kg), protein (140 g CP/kg), probiotics (50 mg/kg) and the combination of these components, while one group was kept as a control. Semen samples were collected weekly and semen volume, spermatozoa concentration, motility and dead spermatozoa percentage were determined. Seminal plasma was separated to determine the concentration of total antioxidant capacity (TAC), homocysteine, paraoxonase (PON1), arylesterase, ceruloplasmin, aspartate aminotransferase (AST) and alanine aminotransferase (ALT) activities. 3. Semen volume was significantly higher in the vitamin E and C groups compared to the control. Spermatozoa motility was higher in the vitamin E group and dead spermatozoa percentage was significantly lower in the vitamin C group compared with the control group. 4. Seminal plasma TAC was higher in the vitamin E group, homocysteine was lower in the vitamin C and E groups. PON1 was higher in the combination group. Arylesterase increased significantly in the vitamin C and combination groups over time. Seminal plasma AST was significantly lower in the vitamin C and E supplemented groups whereas ALT decreased significantly only in the vitamin E group compared with the control. Higher concentrations of ceruloplasmin were observed in the combination group compared with the other treatments. 5. It was concluded that additional vitamin E and C or their combination was the most potent nutrient treatment for improving the semen traits and seminal plasma biochemical characteristics in male broiler breeders after Zn-induced moulting.

Effects of paraoxonase 1 activity and gene polymorphisms on long-term pulmonary complications of sulfur mustard-exposed veterans

Sulfur mustard (SM) is an alkylating agent with prolonged adverse effects. The antioxidant paraoxonase 1 (PON1), an endogenous free radical scavenger, plays a protective role against oxidative stress. The possible roles of oxidative stress in the pathogenesis of SM, together with the antioxidant activity of PON1, are enough to warrant the analysis of PON1 polymorphisms and allelic variants in incapacitated veterans. PON1 55 L/M and 192 Q/R polymorphisms were assayed in 289 male veterans with severe pulmonary conditions, who were exposed to SM 20-25 years ago, and 66 gender-, age- and ethnic-matched healthy controls. As we showed previously the PON1 activity decreased significantly in veterans. However, PON1 55 L/M and 192 Q/R genotype distributions were not significantly different between the veterans and the controls. R and L allele carriers have also significantly higher basal and salt-stimulated PON1 activity than Q and M allele carriers. Paraoxonase and arylesterase activities in individuals with the QQ+(MM or LM) genotype were significantly lower than those with the (RR or QR)+LL genotype. Furthermore, basal and salt-stimulated paraoxonase activity in veterans with the (RR or QR)+LL genotype was significantly lower than that in the controls. A positive correlation has been determined between serum PON1 activity and pulmonary function test in QR/LL genotypes. Some of the veterans with RR+QR genotypes have also shown a novel missense change of Asn227Ser in exon 6 of the enzyme. This substitution is close to the binding domain of PON1 and so modifies enzyme activity.