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Santos R.A.,Grande Rio University | Tesser M.B.,Institute Oceanografia IO | Monserrat J.M.,Grande Rio University
Fish Physiology and Biochemistry | Year: 2016

Lipoic acid (LA) is an antioxidant that also favors glucose uptake in mammals. Until now, there are no studies evaluating the potential effect of this molecule on glycemic control in fish. It was evaluated LA effects on glucose uptake in common carp Cyprinus carpio fed with carbohydrate diets from two carbohydrate sources: glucose (GLU) and starch (STA), and supplemented or not with LA, being the diets: +GLU/−LA (GLU); +GLU/+LA (GLU + LA); +STA/−LA (STA); and +STA/+LA (STA + LA). Carp juveniles (6.5 ± 0.1 g) were fed with each diet ad libitum 4 times a day, during 68 days. Muscle glycogen concentration was higher (p < 0.05) in GLU and GLU + LA than in STA and STA + LA groups. On fish fed with starch, muscle cholesterol and triglyceride concentrations were higher (p < 0.05) in fish fed diets supplemented with LA. Muscle protein levels were higher in fish fed with LA, independent of the diet carbohydrate source. Lipid peroxidation was significantly reduced (p < 0.05) in fish muscle on fish fed the STA + LA diets when compared with the STA diet. Our findings indicate that LA modulates lipid, proteins and carbohydrate metabolism together with the well-known antioxidant effect. Also, LA showed to enhance starch utilization taking into account muscle cholesterol and triglyceride levels. © 2016 Springer Science+Business Media Dordrecht

Martins A.C.B.,Grande Rio University | Kinas P.G.,Grande Rio University | Kinas P.G.,Institute Matematica | Marangoni J.C.,Grande Rio University | And 4 more authors.
Aquatic Ecology | Year: 2015

The present study characterizes the fish assemblage in the surf zone of Cassino Beach, Rio Grande, Brazil, and analyzes temporal fluctuations in richness and abundance of these species in medium (months) and long terms (years), associating them also with abiotic covariates. Data were collected monthly between 1996 and 2012 at two locations. Bayesian generalized additive models (GAMs) were used as statistical tool, placing this study among few that have used Bayesian GAMs in Ecology. Our results show a decrease in both species richness and abundance of the most representative species, over the last 16 years, but no significant distinction between locations. Water temperature and salinity along with seasonality were the statistically most influential explanatory covariates to describe fluctuations in richness and abundance. Higher discharge rates of the three main rivers that flow into Patos Lagoon (Jacuí, Taquari, Camaquã) were associated with increased richness and abundance of some species in the assemblage. Hence, our findings show that medium- and long-term fluctuations in richness and species abundance are controlled by abiotic factors related to seasonal cycles (temperature) and productivity of the ecosystem. Long-term changes seem to be also related to man-induced factors and climate change; but further research is needed. © 2015, Springer Science+Business Media Dordrecht.

da Silva Martins A.C.,Grande Rio University | Artigas Flores J.,Grande Rio University | Porto C.,Grande Rio University | Wasielesky Junior W.,Grande Rio University | And 2 more authors.
Marine and Freshwater Behaviour and Physiology | Year: 2015

Shrimp (Litopenaeus vannamei) reared in a conventional seawater (SW) aquarium system SW were compared with those raised in a biofloc technology (BFT) system. After 30 days, the L. vannamei shrimp were euthanized and samples of gills, hepatopancreas and muscle were dissected. Statistical analysis was performed using bi-factorial ANOVA, with the factors of the treatment (shrimp reared in SW or in a BFT system) and organs (gills, hepatopancreas and muscles). No differences (p > 0.05) in glutathione-S-transferase activity were observed between shrimp reared in SW and shrimp reared in BFT (p < 0.05). Glutathione levels were lower (p < 0.05) in the gills and hepatopancreas of shrimp reared in the BFT system, suggesting changes in the antioxidant composition of these organs. Lipid peroxidation levels were higher in the hepatopancreas than in muscle in shrimp reared in SW (p < 0.05) and this difference was not observed in organisms reared in the BFT system (p > 0.05). Overall, the results showed that rearing shrimp in the BFT system altered both their antioxidant and oxidative damage responses. This indicates that some microbial communities in BFT systems can influence the redox state of L. vannamei. © 2015 Taylor & Francis.

Enamorado A.D.,Grande Rio University | Martins A.C.,Grande Rio University | Flores J.A.,Grande Rio University | Tesser M.B.,Grande Rio University | And 5 more authors.
Comparative Biochemistry and Physiology -Part A : Molecular and Integrative Physiology | Year: 2015

The current study aimed to evaluate the influence of lipoic acid (LA) supplementation (439.84 ± 6.71. mg LA/kg feed) on antioxidants responses throughout the time in intestine, liver and muscle of juvenile common carp Cyprinus carpio. Two experimental groups were fed during four weeks with a diet with or without LA. Glutathione-S-transferase (GST) activity, glutathione (GSH) content, antioxidant capacity against peroxyl radicals (ACAP) and lipid peroxidation (TBARS) were evaluated in these organs. Also, a technique to measure protein disulfide bonds and sulfhydryl groups was optimized for intestine samples. GST activity was significantly higher (p. <0.05) in intestine after two weeks of supplementation. GSH content was also significantly higher (p. <0.05) in intestine, liver and muscle of fish fed with LA after two and three weeks, respectively. Total capacity antioxidant against peroxyl radicals was significantly increased (p. <0.05) in the muscle of animals fed with LA after the fourth week. Concentration of disulfide bonds was higher in the intestine of fish fed with LA but this group also showed higher concentration of sulfhydryl groups (p. <0.05). It is concluded that supplementation with LA is a safe strategy to induce antioxidant responses and improves the antioxidant status in different organs of common carp. Two week of supplementation are required to induce antioxidant responses in intestine and liver and three week for muscle. © 2015 Elsevier Inc.

da Silva Martins A.C.,Grande Rio University | Flores J.A.,Grande Rio University | Junior W.W.,Grande Rio University | Junior W.W.,Institute Oceanografia IO | And 6 more authors.
Marine and Freshwater Behaviour and Physiology | Year: 2014

The effect of lipoic acid supplementation and moderate hypoxia (3 mg/L), followed by re-oxygenation, was analyzed in terms of antioxidant and oxidative damage responses in juvenile shrimp Litopenaeus vannamei. Lipoic acid (LA)-enriched rations (D1: 76.4 ± 6.4; D2: 196.4 ± 70.2; and D3: 397.2 ± 79.97 mg LA/kg) were offered to shrimps. A control group without LA adding was also run. After 45 days, LA-enriched ration increased the activity of the detoxifying enzyme glutathione-S-transferase in gills. Total antioxidant capacity against peroxy radicals was augmented in gills and hepatopancreas at doses D2 and D3. Doses D1 and D2 of LA reduced the levels of oxidative damage (lipid peroxidation) in gills and hepatopancreas. The results showed that certain LA doses (particularly D2) improved not only antioxidant responses but also weight gain. It can be concluded that LA triggered antioxidant and detoxification protection in L. vannamei, allowing the shrimp to cope with environmental stressful factors. © 2014 Taylor & Francis.

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