1,721,014 research outputs found
Effect of media with different glycerol concentrations on sheep red blood cells’ viability in vitro
No full textThe use of high doses of glycerol as a livestock feed supplement is followed by a rapid increase in plasma concentrations and consequently in plasma osmolality. Moreover, glycerol is a highly diffusible molecule that can readily permeate the red blood cell (RBC) membrane following a concentration gradient. A rise in glycerol plasma concentrations can thus alter RBC homeostasis. The present study aimed at investigating both glycerol osmotic effects on sheep RBCs and their oxidative response under in vitro conditions. Sheep blood samples were suspended in media supplemented with increasing glycerol concentrations (0, 25, 50, 100, 150, 200, 250, 300, 350, 400 mg/dL), which reflected those found in vivo in previous studies, and incubated at 37 °C for 4h. Thereafter, osmolality and hemolysis were determined in spent media, while cell extracts were used to assay intracellular concentration of glycerol, ATP, Ca2+ ions, oxidative stress markers and reactive oxygen species (ROS).The study confirmed that glycerol intracellular concentrations are directly related with its concentration in the incubation media, as well as hemolysis (p < 0.001) which increased significantly at glycerol concentrations higher form 200 mg/dL. ROS intracellular level increased at all glycerol concentration tested (p < 0.01) and total thiols decreased at the highest concentrations. However, RBCs proved to be able to cope by activating their antioxidant defense system. Superoxide dismutase activity indeed increased at the highest glycerol concentrations (p < 0.001), while total antioxidant capacity and malonyldialdehyde, a typical product of lipid peroxidation by ROS, did not show significant changes. Moreover, no alterations in intracellular Ca2+ ions and ATP concentrations were found. In conclusion, glycerol‐induced hemolysis can be related to the induced osmotic stress. In sheep, nutritional treatments should be designed to avoid reaching glycerol circulating concentrations higher than 200 mg/dL
Bisphenol a and bisphenol S oxidative effects in sheep red blood cells: An in vitro study
No full textBisphenols (BPs) are plastic components widely used worldwide and occurring in the environment. Exposure to these compounds is known to be harmful for animals and humans at different levels. The aim of this study was to evaluate and compare the oxidative effects of bisphenol A (BPA) and bisphenol S (BPS) in sheep. Reactive oxygen species (ROS) production and correlated structural alterations in sheep erythrocytes were investigated in vitro. Blood samples from four ewes were collected at fasting from the jugular vein using vacuum collection tubes containing EDTA. For ROS assay in erythrocytes, blood was properly diluted and BPA or BPS was added to obtain final bisphenol concentrations in the range between 1 and 300 μM. 2′,7′-Dichlorodihydrofluorescein diacetate (H2DCF-DA) 3 μM was added to the samples, and fluorescence was read in four replicates using a microplate reader. To evaluate erythrocyte shape, blood smears of blood treated with the different concentrations of BPS and BPA were prepared. A significant increase in ROS production was observed when concentrations of BPS and BPA increased from 1 to 100 μM (p < 0:05). At the higher concentrations of the two studied BPs (300 μM of BPS and 200-300 μM of BPA), a ROS decrease was observed when compared to the control group (p < 0:01). Erythrocytes' shape alterations were observed in cells treated with BPS and BPA 200-300 μM 4 hours after the beginning of the treatment. This study confirms that BPA and BPS exhibit oxidative effects on sheep erythrocytes. At higher concentrations, BPA was able to modify erythrocytes' shape, while BPS altered their membrane as a sign of a protein clustering that could lead to eryptosis. These BPs' effects are consequent to intracellular ROS increase
Evaluation of curcuma and ginger mixture ability to prevent ROS production induced by bisphenol S: an in vitro study
No full textThe use of bisphenol S (BPS) as a substitute of Bisphenol A is increasing in several products and it can be found in different environmental and biological matrices. Its toxicity has been studied at different levels and one of BPS toxic mechanisms at high concentrations seems to be the induction of oxidative stress through the generation of reactive oxygen species (ROS). This study evaluates the ability of a curcuma and ginger (CG) mixture to exert an antioxidant effect on rat hepatocytes treated with BPS. The effects of the mixture were compared to those of a well-known antioxidant (Trolox). Three different BPS concentrations were used in order to verify ROS production. 70 μg/mL and 150 μg/mL of BPS generated a significant ROS increase (p < 0.01) as compared to control, while CG mixture was able to decrease this ROS production in hepatic cells, as compared to cells treated with 70 μg/ml of BPS (p < 0.01) restoring control levels. BPS 70 μg/mL was tested for total antioxidant capacity (TEAC), superoxide dismutase (SOD) and total thiols. TEAC and SOD significant decreased (p < 0.05 and p < 0.01, respectively) as compared to controls and CG mixture was able to restore control values. Given the widespread BPS use, results obtained in this study can be of high impact for the community, demonstrating the ability of a mixture of natural products to prevent BPS-induced oxidative stress
Measurement of progesterone in sheep using a commercial ELISA kit for human plasma
No full textDetermination of serum or plasma progesterone (P4) concentrations is important to recognize pregnant and non-pregnant ewes, and also to predict the number of carried lambs. The 2 most common methodologies for the detection of plasma P4 are radioimmunoassay (RIA) and enzyme immunoassay (EIA). RIA is very expensive, and not all laboratories are equipped to perform this test; EIA is commercially available for human use, but only a few companies produce species-specific kits, which are expensive. We verified for ovine plasma a less expensive and easily available ELISA kit (DiaMetra) designed to quantify P4 in humans. Pools of ovine and human plasma were used to compare repeatability, accuracy, sensitivity, and stability of P4 measured by the DiaMetra kit. Repeatability data were within 15%, and accuracy values were ~90% for both plasma matrices. Stability data showed a loss of <20% for freeze–thaw and <30% for 30-d storage. All parameters were acceptable under international guidelines for method validation. The human ELISA kit was used successfully to quantify plasma P4 in 26 ewes during pregnancy until delivery. P4 concentrations were also correlated with the number of carried lambs
Comparsa dei picchi preovulatori di LH dopo integrazione luminosa ed effetto maschio nella capra Sarda in anaestro
No full textEffetto di giorni lunghi e melatonina sulla risposta all'effetto maschio nella capra Sarda
No full textApparition des pics de LH chez la chèvre Sarde après traitement lumineux et effet male
No full textEffet des jours longs et de la mélatonine sur la réponse à l’effet mâle chez la chèvre Sarde
No full textNon-invasive Assay for Measurement of Fecal Triiodothyronine (T3) Metabolite Levels in European Mouflon (Ovis aries musimon)
Full text linkThyroid hormones (THs) are important indicators of metabolism and animal health. Traditionally, they have been determined from blood or urine samples. However, as their collection may be stressful and requires ethical approval, alternative non-invasive matrices are preferred when dealing with wild animals. Triiodothyronine (T3) is the active form of THs in blood and the major metabolite excreted in feces. This creates the ideal conditions for its assay in fecal samples. Fecal sampling eliminates the stress of the animals and the need to physically capture them. However, in wild species it is rare to find species-specific kits for the hormone assay. So, the objective of this work was to validate a method for the quantification of T3 metabolite (FTM) levels in feces of European mouflon by using an economic and easily available ELISA kit designed to quantify T3 in human plasma. Analytical and biological validations were performed in feces collected from 10 mouflons (5 ewes and 5 rams). An efficient liquid-extraction method was optimized. Precision, dilution linearity, parallelism, recovery and stability of T3 in fecal samples were calculated. Obtained data were considered acceptable according to international guidelines. The reliability of the results was verified comparing human plasma and mouflon fecal samples fortified with the same T3 standard solutions. The biological validation showed higher FTM levels in March compared to June, and no differences between mouflon ewes and rams. The validation of the present method provides a non-invasive and affordable tool for the quantification of FTM in European mouflon
Measurement of fecal T3 metabolite levels in sheep: Analytical and biological validation of the method
No full textIntroduction: Biological sample collection from wild and farms animals is often associated with difficulties related to the handling and restraint procedures, and most of the time it could induce stress, altering the welfare and physiological homeostasis. The analysis of fecal T3 metabolites (FTMs) allows to test samples collected in a non-invasive manner, providing several information about the animal's physiological conditions and the effects related to environmental and nutritional variations. This procedure has found wide application in wild species, but less in domestic ones. Methods: The aim of this work was to validate the use of an immuno-enzymatic competitive ELISA kit, designed for T3 quantification in human blood serum samples, for the assessment of FTMs in the sheep. For the analytical validation, precision, recovery and parallelism were evaluated; for biological validation the variations of FTMs in relation to age, sex and the physiological status of the animal were determined. Results: After a verification of the precision (RSD % < 15%), mean recovery (75%) and parallelism (CV% < 10%), the kit was used to measure FTMs in cyclic, pregnant, and early lactating ewes as well as in rams and ewe lambs. The results showed that FTMs concentrations in pregnant ewes were significantly lower (p < 0.05) than in cyclic and early lactation ones. Furthermore, there were no significant differences in FTMs levels between ewes and rams, while in lambs FTMs levels were higher than in adults (p < 0.001). Conclusion: In conclusion the present study demonstrates that FTMs can be reliably and accurately determined in sheep feces, using an ELISA kit formulated for human serum T3 assay. The application of this method in the livestock sector could allow to improve our knowledge about the response of animals to different physiological and environmental conditions, and thus assess their welfare
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