Vanessa Labrada-Martagón

Oxidative stress indicators and chemical contaminants in East Pacific green turtles (Chelonia mydas) inhabiting two foraging coastal lagoons in the Baja California peninsula.

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.

Health Indices of the Green Turtle (Chelonia mydas) Along the Pacific Coast of Baja California Sur, Mexico. I. Blood Biochemistry Values

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.

Health Indices of the Green Turtle (Chelonia mydas) Along the Pacific Coast of Baja California Sur, Mexico. II. Body Condition Index

Abstract Body condition index is used as a measure for an individuals 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 (<u200977 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.

Oxidative stress indicators and trace element concentrations in tissues of mako shark (Isurus oxyrinchus).

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.

Incremento de la temperatura ambiental y su posible asociación al suicidio en Baja California Sur (BCS) 1985-2008

Introduccion. Durante las ultimas decadas se ha podido apreciar un cambio en las variables climaticas, en especial en la temperatura ambiental. Hay evidencias que asocian el aumento de la temperatura ambiental con el incremento en las tasas de mortalidad por suicidio. Objetivo. Evaluar la relacion entre la tasa de suicidio y la temperatura ambiental en Baja California Sur (BCS) durante los anos 1985-2008. Metodo. Los datos de suicidio fueron obtenidos de las bases de Mortalidad del INEGI de 1985-2008. Se tabularon los registros con codigos: E950-E959 CIE-9 y X60-X84, Y87.0 CIE-10 para BCS. En el analisis climatico se usaron las temperaturas maximas de 1985 al 2008 para BCS del Extractor Rapido de Informacion Climatologica (ERIC III). Para evaluar la tendencia, se utilizaron modelos de regresion lineal y cuadraticos. Los modelos lineales generalizados (GLM) se utilizaron para evaluar el efecto de las variables ambientales sobre la tasa de suicidios, con una significancia de p=0.05. Resultados. Un total de 582 suicidios ocurrieron en BCS de 1985 a 2008. Las mujeres representaron el 9% (53), con tasa anual promedio de 1.6/100 000. Los hombres 91% (529), con tasa promedio anual de 16.3/100 000. La tendencia de incremento anual se explico con modelos lineales simples y cuadraticos en ambas temporadas. En los meses calidos el modelo cuadratico explico mejor dicho incremento (R2=0.64 p<0.01). La temperatura se correlaciono positivamente con la tasa en ambas temporadas (p<0.01). Se generaron dos modelos GLM predictivos por temporada. Discusion. En este trabajo se observo una posible relacion entre el incremento de la temperatura ambiental y el numero de suicidios registrados durante 24 anos en BCS. Esta relacion se encuentra bien definida en los meses calidos, pero con una tendencia en aumento para los meses frios.

Purine nucleoside phosphorylase and the enzymatic antioxidant defense system in breast milk from women with different levels of arsenic exposure

Purine nucleoside phosphorylase (PNP) is an ubiquitous enzyme which plays an important role in arsenic (As) detoxification. As is a toxic metalloid present in air, soil and water; is abundant in the environment and is readily transferred along the trophic chain, being found even in human breast milk. Milk is the main nutrient source for the growth and development of neonates. Information on breast milk synthesis and its potential defense mechanism against As toxicity is scarce. In this study, PNP and antioxidant enzymes activities, as well as glutathione (GSH) and total arsenic (TAs) concentrations, were quantified in breast milk samples. PNP, superoxide dismutase (SOD), catalase (CAT), glutathione S-transferase (GST), glutathione peroxidase (GPx), glutathione reductase (GR) activities and GSH concentration were determined spectrophotometrically; TAs concentration ([TAs]) was measured by atomic absorption spectrometry. Data suggest an increase in PNP activity (median = 0.034 U mg protein-1) in the presence of TAs (median = 1.16 g L(-1)). To explain the possible association of PNP activity in breast milk with the activity of the antioxidant enzymes as well as with GSH and TAs concentrations, generalized linear models were built. In the adjusted model, GPx and GR activities showed a statistically significant (p<0.01) association with PNP activity. These results may suggest that PNP activity increases in the presence of TAs as part of the detoxification mechanism in breast milk.

Efecto de la interacción entre Mercurio (Hg), Arsénico (As) y Selenio (Se) en la actividad de glutatión S-Transferasa en leche materna: potencial relación con el consumo de pescados y mariscos

Breast milk is regarded as an ideal source of nutrients for the growth and development of neonates, but it can also be a potential source of pollutants. Mothers can be exposed to different contaminants as a result of their lifestyle and environmental pollution. Mercury (Hg) and arsenic (As) could adversely affect the development of fetal and neonatal nervous system. Some fish and shellfish are rich in selenium (Se), an essential trace element that forms part of several enzymes related to the detoxification process, including glutathione S-transferase (GST). The goal of this study was to determine the interaction between Hg, As and Se and analyze its effect on the activity of GST in breast milk. Milk samples were collected from women between day 7 and 10 postpartum. The GST activity was determined spectrophotometrically; total Hg, As and Se concentrations were measured by atomic absorption spectrometry. To explain the possible association of Hg, As and Se concentrations with GST activity in breast milk, generalized linear models were constructed. The model explained 44% of the GST activity measured in breast milk. The GLM suggests that GST activity was positively correlated with Hg, As and Se concentrations. The activity of the enzyme was also explained by the frequency of consumption of marine fish and shellfish in the diet of the breastfeeding women.