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Comparative biochemistry and physiology. Part A, Molecular & integrative physiology 04/2013; · 2.20 Impact Factor
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ABSTRACT: Liver, kidney and muscle from juvenile mako sharks (Isurus oxyrinchus) were collected in Baja California Sur. Lead (Pb), cadmium (Cd), mercury (Hg) and arsenic (As) concentrations were determined by atomic absorption spectrophotometry. The production of superoxide radical (O2(•-)) was measured as an indicator of reactive oxygen species production; lipid peroxidation (TBARS) and protein carbonyl levels were quantified as indicators of oxidative damage, and the activity of the antioxidant enzymes superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione reductase (GR) and glutathione-S-transferase (GST) was assessed as indicator of antioxidant defenses. Two discriminant functions separated muscle from liver and kidney samples. Cd concentration was lower in muscle than in kidney (p<0.05) and Hg concentration was higher in muscle than in liver and kidney (p<0.05). Although GR and SOD activities were higher, oxidative damage (TBARS and carbonyl protein levels) was also higher in kidney (p<0.05). SOD activity, TBARS levels, and Cd and Hg concentration were the set of predictors with significant relevance during tissue discrimination. Tissue metabolism, physiology of the organisms and environmental factors may be related to the differences in trace elements and oxidative stress indicators found in muscle, liver and kidney of the mako shark.
Comparative biochemistry and physiology. Part A, Molecular & integrative physiology 03/2013; · 2.20 Impact Factor
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ABSTRACT: Trace element concentrations and oxidative stress indicators were measured in liver and kidney samples of 35 blue sharks caught by local artisan fisheries on the west coast of Baja California Sur (Mexico). Differences between sex and maturity cohorts, and the interactions of trace elements with oxidative stress indicators were assessed. Significant differences were found in trace element (Hg, As, Zn, Cd, Pb) concentration and oxidative stress indicators (catalase (CAT) activity, superoxide dismutase (SOD) activity, lipid peroxidation, TBARS, levels) between tissues. Significant sex differences (females<males) in the hepatic Zn concentration, and maturity (immature<mature) differences in hepatic GPx activity and renal CAT activity were found. Correlations between oxidative stress indicators and trace element concentrations were found: hepatic GST activity - As concentration, SOD activity - protein carbonyl levels, SOD activity - superoxide radical production and Zn concentration - Cd concentration; renal SOD activity - TBARS levels, protein carbonyl levels - As concentration and protein carbonyl levels - Cu concentration. Trace element concentrations may be important drivers of oxidant and antioxidant processes in sharks and an important consideration in their physiology and health.
Comparative biochemistry and physiology. Part A, Molecular & integrative physiology 02/2013; · 2.20 Impact Factor
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ABSTRACT: Northern elephant seals are naturally adapted to prolonged periods (1-2 months) of absolute food and water deprivation (fasting). In terrestrial mammals, food deprivation stimulates ATP degradation and decreases ATP synthesis, resulting in the accumulation of purines (ATP degradation byproducts). Hypoxanthine-guanine phosphoribosyl transferase (HGPRT) salvages ATP by recycling the purine degradation products derived from xanthine oxidase (XO) metabolism, which also promotes oxidant production. The contributions of HGPRT to purine recycling during prolonged food deprivation in marine mammals are not well defined. In the present study we cloned and characterized the complete and partial cDNA sequences that encode for HGPRT and xanthine oxidoreductase (XOR) in northern elephant seals. We also measured XO protein expression and circulating activity, along with xanthine and hypoxanthine plasma content in fasting northern elephant seal pups. Blood, adipose and muscle tissue samples were collected from animals after 1, 3, 5 and 7 weeks of their natural post-weaning fast. The complete HGPRT and partial XOR cDNA sequences are 771 and 345 bp long and encode proteins of 218 and 115 amino acids, respectively, with conserved domains important for their function and regulation. XOR mRNA and XO protein expression increased 3-fold and 1.7-fold with fasting, respectively, whereas HGPRT mRNA (4-fold) and protein (2-fold) expression increased after 7 weeks in adipose tissue and muscle. Plasma xanthine (3-fold) and hypoxanthine (2.5-fold) levels, and XO (1.7- to 20-fold) and HGPRT (1.5- to 1.7-fold) activities increased during the last 2 weeks of fasting. Results suggest that prolonged fasting in elephant seal pups is associated with increased capacity to recycle purines, which may contribute to ameliorating oxidant production and enhancing the supply of ATP, both of which would be beneficial during prolonged food deprivation and appear to be adaptive in this species.
Journal of Experimental Biology 05/2012; 215(Pt 9):1448-55. · 3.00 Impact Factor
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ABSTRACT: Trace element concentrations and oxidative stress indicators (including production of reactive oxygen species (ROS), antioxidant enzyme activities and oxidative damage) were measured in muscle of blue sharks collected along the west coast of Baja California Sur to determine potential differences by sex and maturity cohorts. Mercury (Hg) concentration in muscle samples from larger sharks (>200 cm LT) exceeded the permissible limit (>1 ppm wet weight) for human consumption set by numerous international agencies. Significant differences were found in Hg concentrations (mature>immature; males>females), and in protein carbonyl concentrations (male>female); however, except for carbonyl protein levels, no significant differences by sex or maturity stage were found in the oxidative stress indicators. Differences between sexes and maturity stages in trace element concentration and carbonyl protein levels in blue shark muscle may be related to variations in diet within different cohorts.
Comparative Biochemistry and Physiology Part C Toxicology & Pharmacology 04/2012; 156(2):59-66. · 2.62 Impact Factor
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ABSTRACT: While diving, seals are exposed to apnea-induced hypoxemia and repetitive cycles of ischemia/reperfusion. While on land, seals experience sleep apnea, as well as prolonged periods of food and water deprivation. Prolonged fasting, sleep apnea, hypoxemia and ischemia/reperfusion increase oxidant production and oxidative stress in terrestrial mammals. In seals, however, neither prolonged fasting nor apnea-induced hypoxemia or ischemia/reperfusion increase systemic or local oxidative damage. The strategies seals evolved to cope with increased oxidant production are reviewed in the present manuscript. Among these strategies, high antioxidant capacity and the oxidant-mediated activation of hormetic responses against hypoxia and oxidative stress are discussed. In addition to expanding our knowledge of the evolution of antioxidant defenses and adaptive responses to oxidative stress, understanding the mechanisms that naturally allow mammals to avoid oxidative damage has the potential to advance our knowledge of oxidative stress-induced pathologies and to enhance the translative value of biomedical therapies in the long term.
Journal of Comparative Physiology B 02/2012; 182(6):741-50. · 1.97 Impact Factor
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ABSTRACT: Extended breath-hold (apnea) bouts are routine during diving and sleeping in seals. These apneas result in oxygen store depletion and blood flow redistribution towards obligatory oxygen-dependent tissues, exposing seals to critical levels of ischemia and hypoxemia. The subsequent reperfusion/reoxygenation has the potential to increase oxidant production and thus oxidative stress. The contributions of extended apnea to oxidative stress in adapted mammals are not well defined. To address the hypothesis that apnea in seals is not associated with increased oxidative damage, blood samples were collected from northern elephant seal pups (N=6) during eupnea, rest- and voluntary submersion-associated apneas, and post-apnea (recovery). Plasma 4-hydroxynonenal (HNE), 8-isoprostanes (8-isoPGF(2α)), nitrotyrosine (NT), protein carbonyls, xanthine and hypoxanthine (HX) levels, along with xanthine oxidase (XO) activity, were measured. Protein content of XO, superoxide dismutase 1 (Cu,ZnSOD), catalase and myoglobin (Mb), as well as the nuclear content of hypoxia inducible factor 1α (HIF-1α) and NF-E2-related factor 2 (Nrf2), were measured in muscle biopsies collected before and after the breath-hold trials. HNE, 8-iso PGF(2α), NT and protein carbonyl levels did not change among eupnea, apnea or recovery. XO activity and HX and xanthine concentrations were increased at the end of the apneas and during recovery. Muscle protein content of XO, CuZnSOD, catalase, Mb, HIF-1α and Nrf2 increased 25-70% after apnea. Results suggest that rather than inducing the damaging effects of hypoxemia and ischemia/reperfusion that have been reported in non-diving mammals, apnea in seals stimulates the oxidative stress and hypoxic hormetic responses, allowing these mammals to cope with the potentially detrimental effects associated with this condition.
Journal of Experimental Biology 12/2011; 214(Pt 24):4193-200. · 3.00 Impact Factor
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11/2011: pages 127 - 137; , ISBN: 9781444345988
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ABSTRACT: Maturation in hooded seals is characterized by the rapid development of their physiological diving capacity and is accompanied by increases in oxidant production but not oxidative damage. To test the hypothesis that the antioxidant system of hooded seals develops as they transition from a terrestrial to an aquatic environment, we obtained the complete cDNA sequence that encodes the NF-E2-related factor 2 (Nrf2), a central regulator of the antioxidant response, and compared Nrf2 mRNA and protein expression levels in muscle samples from neonate, weaned pups and adult hooded seals, along with glutathione (GSH) levels and the activity/protein content of the antioxidant enzymes catalase, glutathione peroxidase (GPx), peroxyredoxin VI (PrxVI), thioredoxin 1 (Trx1), thioredoxin reductase (TrxR), glutaredoxin 1 (Glrx1), glutathione disulphide reductase, glutathione S-transferase and glutamate-cysteine ligase. The Nrf2 of the hooded seal is 1822 bp long and encodes a protein of 606 amino acids with a leucine zipper domain and Keap1-mediated proteosomal degradation residues, which are key for Nrf2 function and regulation. Although neither Nrf2 mRNA nor Nrf2 nuclear protein content are higher in adults than in pups, GSH levels along with GPx, PrxVI, Trx1, TrxR and Glrx1 activity/protein content increase with maturation, suggesting that the potential for peroxide removal increases with development in hooded seals, and that these enzymes contribute to the regulation of the intracellular redox state and the prevention of oxidative damage in these deep-diving mammals.
Journal of Experimental Biology 09/2011; 214(Pt 17):2903-10. · 3.00 Impact Factor
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ABSTRACT: Northern elephant seals experience prolonged periods of absolute food and water deprivation (fasting) while breeding, molting or weaning. The postweaning fast in elephant seals is characterized by increases in the renin-angiotensin system, expression of the oxidant-producing protein Nox4, and NADPH oxidase activity; however, these increases are not correlated with increased oxidative damage or inflammation. Glutathione (GSH) is a potent reductant and a cofactor for glutathione peroxidases (GPx), glutathione-S transferases (GST) and 1-cys peroxiredoxin (PrxVI) and thus contributes to the removal of hydroperoxides, preventing oxidative damage. The effects of prolonged food deprivation on the GSH system are not well described in mammals. To test our hypothesis that GSH biosynthesis increases with fasting in postweaned elephant seals, we measured circulating and muscle GSH content at the early and late phases of the postweaning fast in elephant seals along with the activity/protein content of glutamate-cysteine ligase [GCL; catalytic (GCLc) and modulatory (GCLm) subunits], γ-glutamyl transpeptidase (GGT), glutathione disulphide reductase (GR), glucose-6-phosphate dehydrogenase (G6PDH), GST and PrxVI, as well as plasma changes in γ-glutamyl amino acids, glutamate and glutamine. GSH increased two- to four-fold with fasting along with a 40-50% increase in the content of GCLm and GCLc, a 75% increase in GGT activity, a two- to 2.5-fold increase in GR, G6PDH and GST activities and a 30% increase in PrxVI content. Plasma γ-glutamyl glutamine, γ-glutamyl isoleucine and γ-glutamyl methionine also increased with fasting whereas glutamate and glutamine decreased. Results indicate that GSH biosynthesis increases with fasting and that GSH contributes to counteracting hydroperoxide production, preventing oxidative damage in fasting seals.
Journal of Experimental Biology 04/2011; 214(Pt 8):1294-9. · 3.00 Impact Factor
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ABSTRACT: In order to determine the potential effects of contaminants in juveniles of East Pacific green turtle, Chelonia mydas, captured alive, circulating trace metal and organochlorine pesticide concentrations were correlated with body condition, antioxidant enzyme activities and lipid peroxidation levels. Turtles were sampled in Punta Abreojos (PAO) and Bahía Magdalena (BMA). Turtles from PAO showed higher silicon and cadmium concentrations, but lower α-hexachlorocyclohexane, γ-hexachlorocyclohexane, hexachlorobenzene and aldrin concentrations than individuals from BMA. In BMA cadmium concentration decreased as the standard carapace length of the turtles increased. In PAO concentrations of α-hexachlorocyclohexane, heptachlor and hexachlorobenzene were positively correlated with the weight of the individuals. Lipid peroxidation levels were positively correlated with cadmium concentrations. In turtles captured in PAO, enzymatic antioxidant activities correlated mostly with pesticide concentrations, while in individuals from BMA enzyme activities were correlated with trace element concentrations. Correlations between antioxidant enzyme activities and concentration of xenobiotics suggest physiological sensitivity of East Pacific green turtles to chemicals. Regional differences found could be influenced by habitat conditions such as currents, upwellings (PAO) and agricultural activities (BMA). We suggest that, combined, circulating contaminant concentrations, lipid peroxidation levels and antioxidant enzyme activities in sea turtles could be used as biomarkers of the habitat conditions.
Comparative Biochemistry and Physiology Part C Toxicology & Pharmacology 03/2011; 154(2):65-75. · 2.62 Impact Factor
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ABSTRACT: Body condition index is used as a measure for an individual's condition, usually with reference to its nutritional status and the energy reserves. Reproductive success, survival, and thus, population dynamics, depend on body condition of the organisms. In this study, the seasonal and annual body condition factor (a) and the relative body condition index (Krel) were estimated from the length–weight relationship of green turtles (Chelonia mydas) collected in 3 coastal lagoons of Baja California Sur during 2005–2007. Seasonal and annual differences in a, and differences between study sites and physical appearance (healthy or injured) of Krel were analyzed. Juveniles were the predominant age class (< 77 cm straight carapace length). Green turtles from Punta Abreojos (PAO) had a lower Krel than individuals of Laguna San Ignacio at a given size. In Bahía Magdalena (BMA) and PAO injured green turtles had a smaller Krel than turtles classified as healthy at a given size. Additionally, the increase in Krel per cm of straight carapace length of injured green turtles from PAO was lower than that of healthy ones. Body condition factor, a, varied between years in turtles from PAO, being highest during 2006. An increasing tendency in a, from winter to summer, was observed in PAO and BMA. The periods when green turtles had the highest body condition factor a (summer, 2005 BMA, 2006 PAO) coincided with periods of highest serum concentrations of glucose, proteins, lipids, calcium, and uric acid; nevertheless, the relative body condition index was not correlated with those parameters. The relative body condition index resulted in a simple and sensible method that provided an overall trend of the data under a number of stress conditions, detecting differences also between injured and healthy individuals. The body condition factor, in conjunction with blood biochemistry parameters, proved to be a useful tool as biomarkers of the apparent physical and nutritional status of the green sea turtles.
Chelonian Conservation and Biology 01/2011; · 0.91 Impact Factor
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ABSTRACT: The green sea turtle (also known locally as black turtle; Chelonia mydas) is 1 of 5 species of sea turtles found along the coast of the state of Baja California Sur, Mexico, where several bays and lagoon systems provide an important growth and feeding habitat. We characterized blood biochemistry values of 67 green turtles captured at 2 mangrove estuaries along the Pacific coast of the Baja California Peninsula, Mexico, from 2005 to 2007. Blood samples were collected from live turtles for biochemical analysis of 18 parameters and analyzed by physical state (healthy, injured), size classes, season, and geographic location. Green turtles showed differences in the variability of the biochemical parameters between the 2 sites. In Punta Abreojos, injured sea turtles had lower calcium (28%), potassium (28%), and inorganic phosphorus (34.5%) levels and higher cholinesterase activity (16%) compared to healthy turtles. Juvenile turtles collected in Bahía Magdalena had higher glucose levels (34%) than subadults. Levels of triglycerides, total proteins, and albumin correlated positively with size. During the summer and during the years 2005 (Bahía Magdalena, BMA) and 2006 (Punta Abreojos, PAO), individuals had significantly higher concentrations of lipid (cholesterol and triglycerides), glucose, uric acid, and protein. Differences in the habitat, food availability, and environmental conditions between BMA and PAO were reflected in the variability of the biochemical parameters when compared by different factors, such as physical state, size, and seasonality. This is the first report of blood biochemical values of green sea turtles in the Pacific coast of Baja California, Mexico. All serum chemistry values of green sea turtles were within published reference ranges of healthy sea turtle population.
Chelonian Conservation and Biology 01/2011; · 0.91 Impact Factor
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ABSTRACT: The diving response in marine mammals results in bradycardia and peripheral vasoconstriction, with blood flow redistributing preferentially to nervous and cardiac tissues. Therefore, some tissues are rendered ischemic during a dive; with the first breath after a dive, blood flow to all tissues is reestablished. In terrestrial mammals, reactive oxygen species (ROS) production increases in response to ischemia/reperfusion and oxidative damage can occur. The capacity of marine mammals to tolerate repeated ischemia/reperfusion cycles associated with diving appears to be due to an enhanced antioxidant system. However, it is not known if diving depth and/or duration elicit differences in tissue capacity to produce ROS and antioxidant defenses in marine mammals. The objective of this study was to analyze ROS production, antioxidant defenses and oxidative damage in marine mammal species that perform shallow/short vs. deep/long dives. We measured production of superoxide radical (O(2)(•-)), oxidative damage to lipids and proteins, activity of antioxidant enzymes, and glutathione levels in tissues from shallow/short divers (Tursiops truncatus) and deep/long divers (Kogia spp.). We found that differences between the diving capacity of dolphins and Kogia spp. are reflected in O(2)(•-) production and antioxidant levels. These differences suggest that shallow/short and deep/long divers have distinct mechanisms to successfully maintain redox balance.
Comparative biochemistry and physiology. Part A, Molecular & integrative physiology 12/2010; 158(4):438-43. · 2.20 Impact Factor
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ABSTRACT: Pelagic sharks, unlike teleost fish, require constant active swimming to obtain a suitable oxygen (O(2)) supply. An increase in O(2) consumption during exercise enhances production of reactive oxygen species (ROS). We hypothesized that shark species that display vigorous exercise, such as Isurus oxyrinchus and Carcharhinus falciformis, have higher ROS production and, in consequence, higher antioxidant enzyme activities in muscle in comparison with species with less active swimming, like Sphyrna zygaena. Superoxide radical (O(2)(*-)) production, lipid peroxidation levels (TBARS) and the activity of antioxidant enzymes: superoxide dismutase (total, t-SOD; manganese-dependent, Mn-SOD, and copper and zinc-dependent, Cu, Zn-SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione-S-transferase (GST) and glutathione reductase (GR), were measured by spectrophotometric assays in skeletal muscle extracts of three shark species (C. falciformis, I. oxyrinchus and S. zygaena). Higher O(2)(*-) production and GPx and GST activities (p<0.05) were found in C. falciformis and I. oxyrinchus than in S. zygaena. These results suggest that in antioxidant enzymes (GPx, GST) activity suffices to balance the production of ROS and to maintain lower TBARS levels (p<0.05) than in C. falciformis or S. zygaena, contributing to the capacity of I. oxyrinchus to maintain high muscular activity.
Comparative biochemistry and physiology. Part A, Molecular & integrative physiology 05/2010; 156(1):50-6. · 2.20 Impact Factor
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ABSTRACT: The present study reports unique data on concentrations of several classes of organochlorine pesticides and polychlorinated biphenyls in blubber biopsies from healthy living fin whales (Balaenoptera physalus) from the Gulf of California, Mexico, one of the most isolated and unstudied population in the world. OC levels in this population were generally lower than levels reported in fin whales from other regions. The rank order of OCs were SigmaDDTs (range from 300 to 2400 ng g(-1) lw) > SigmaPCBs (range from 40 to 290 ng g(-1) lw) > SigmaHCHs (range from <LOQ to 92 ng g(-1) lw) > or = SigmaCHLORs (from < LOQ to 100 ng g(-1) lw). The most abundant OC pesticide measured was the DDT metabolite, p,p'-DDE. The PCBs 138, 153, and 180 were the most abundant PCBs congeners found in the fin whales samples. Males had significant higher concentrations of SigmaOC, SigmaDDTs and SigmaPCBs than females (P < 0.05), although the p,p'-DDE/SigmaDDTs ratios were similar between the sexes. Although the OC concentrations found in this population were generally below the levels that would be expected to cause deleterious health effects, the maximum values observed (2700 ng g(-1) lw) in some animals were higher than those associated with reproductive effects in whales. Given the small population size and highly isolated characteristics of Gulf of California fin whales, health effects in individuals could readily translate into population-level effects. Future research on this topic will be necessary to better understand the role that these compounds may have on the health of this population.
Environmental Toxicology 05/2009; 25(4):381-90. · 2.41 Impact Factor
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ABSTRACT: We report concentrations of several classes of organochlorines (OCs) in the blubber of California sea lions (Zalophus californianus) from the Gulf of California. Summed OC levels measured in 34 wild-ranging animals were, in general, lower than those previously
reported in sea lions from the eastern Pacific. The rank order of OCs was ΣDDTs (mean=3400ng g−1 lipid weight [lw]) > ΣPCBs (1400ng g−1lw) > ΣHCHs (50ng g−1lw) ≥ ΣCHLORs (46ng g−1lw). The most abundant OC measured was the DDT metabolite, p,p′-DDE. No significant differences in OC profiles were found between genders or rookeries. Although the mean concentrations
of OCs measured in adult males and females were similar, only adult females had significantly higher (p<0.05) mean blubber concentrations of ∑DDTs and ∑HCHs than pups.
Archives of Environmental Contamination and Toxicology 01/2009; 56(2):350-359. · 1.93 Impact Factor
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ABSTRACT: To assess the safety for human consumption of commercially important bivalves harvested from areas with or without mining activities, we compared the levels of heavy metals in mollusks collected from different coastal environments along the Gulf of California. We sampled the mussel Mytilus edulis and the clams Laevicardium elatum and Megapitaria squalida (June 2004) and the clam Chione californiensis (November 2006). Concentrations of cadmium, lead, nickel, zinc, iron, copper, and manganese in the soft tissue of the mollusks were measured by atomic absorption spectrophotometry. Based on dry weight, the highest average concentrations of iron, copper, and cadmium were found in clams from Loreto (572, 181, and 4.66 mg/kg, respectively); that of nickel, in mussels from San Luquitas (12.2 mg/kg); that of zinc, both in mussels from San Luquitas and in clams from Golfo de Santa Clara (94.3 and 91.8 mg/kg, respectively); and those of lead and manganese in clams from the Golfo de Santa Clara (9.2 and 3.68 mg/kg, respectively). Although mollusks were taken from coastal areas of the Gulf of California, which are considered to be contaminated by mining activities, the heavy metals in the sediments apparently were in a chemical form that had low bioavailability for the bivalves feeding in those areas. The interplay of oceanographic conditions and the chemical composition of anthropogenic inputs into the environment is not well understood. Thus, these factors or their interaction could potentially result in increased concentration and bioavailability of such metals in areas without effluent generated by mining activities.
Archives of Environmental Contamination and Toxicology 10/2008; 57(1):96-102. · 1.93 Impact Factor
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ABSTRACT: The black chocolate clam Megapitaria squalida is a commercially important bivalve along the Pacific coast of Mexico and is used as a bioindicator in environmental health studies. Previous studies of Bahía de La Paz indicated significant differences in heavy metal content among localities in this clam. To identify areas affected by heavy metal pollution, lipid peroxidation (TBARS) levels and activity of superoxide dismutase (SOD) and glutathione S-transferase (GST) were measured in muscle, gonad, and digestive gland tissue and correlated with heavy metal levels of clams from six localities along the shore of the bay. Significant differences in TBARS levels and antioxidant enzyme activity were found among these tissues at all localities. Such differences are ascribed to the physiology of each organ. Higher levels of TBARS were found in areas with higher cadmium content. SOD activity in muscle correlated positively with cadmium, lead, and iron in areas with a higher content of those elements. This study suggests that TBARS levels and SOD and GST activity are affected by biotic and abiotic factors and have potential as indicators of heavy metal contamination.
Archives of Environmental Contamination and Toxicology 04/2008; 56(1):60-6. · 1.93 Impact Factor
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ABSTRACT: Latin American researchers in science and engineering (S&E), including those in biology and biomedical sciences, are frequently exposed to unstable conditions of financial support, material and human resources, and a limited number of positions at public and private institutions. Such uncertainties impose continuous challenges for the scientific community which, in the best of cases, responds with careful planning and creativity, and in the worst scenario endures the migration of scientists to the USA or Europe. Still, the number of scientific publications from Latin American institutions in the last decade increased at a much faster rate than publications from the USA and Canada. A brief analysis per country of the gross domestic product (GDP) spent in research and development (R&D) and the S&E production reported by the Pascal bibliographic database suggests that the number and quality of S&E publications is directly proportional to the financial support for R&D. However, the investment in R&D in Latin America did not increase at the same rate (from 0.49 to 0.55% of GDP, from 1990 to 2003) at which S&E publications did in the same period (2.9-fold increase, from 1988 to 2001). In Latin America, the traditional financial support for scientific research continues to be from federal and state government funds, associated in some cases with institutional funds that are mostly directed towards administrative costs and infrastructure maintenance. The aim of this introduction is to briefly discuss the production cost of articles published in refereed S&E journals, including the cost of the scientific research behind them, and, at the same time, to increase the awareness of the high quality of scientific research in Latin American institutions despite the many challenges, especially financial constraints, faced by their scientists. The second issue of Comparative Biochemistry and Physiology dedicated to Latin America ("The Face of Latin American Comparative Biochemistry and Physiology") celebrates, by means of 26 manuscripts from five countries, the diversity and quality of biological science in the continent.
Comparative Biochemistry and Physiology - Part A Molecular & Integrative Physiology 04/2007; 146(4):463-9. · 2.23 Impact Factor
