Concentrations In Muscle Tissue Research Articles

Assessment of trace metal concentrations in muscle tissue of certain commercially available fish species from Kayseri, Turkey

Regular consumption of fish has been widely recommended by health authorities. However, it is known that some species accumulate high levels of contaminants including heavy metals (e.g., Hg, Cd, Pb, and As). In this study, Cu, Pb, Co, Ni, Cr, Mn, Cd, and Fe were determined in the muscle tissue of 11 commercially available fish species (Sparus auratus, Dicentrarchus labrax, Mullus barbatus, Belone belone, Psetta maxima, Epinephelus aeneus, Salmothymus, Soleidae, Pomatomus saltatrix, Engraulis encrasicolus, and Sarda sarda) supplied from retailers in Kayseri, Turkey. Determinations were carried out by flame atomic absorption spectrometry after the wet digestion method. The average metal concentrations of the 11 species were determined in the range of 0.54-1.79, 0.82-1.40, 2.38-4.54, 1.23-3.67, 5.01-5.97, 0.77-3.59, 0.48-1.06, and 5.05-122.8μg/g wet weight for Cu, Pb, Co, Ni, Cr, Mn, Cd, and Fe, respectively. The permissible tolerable daily intake (PTDI) and calculated daily intake (CDI) values were compared, and the calculated daily intake values of the samples were found to be below the established values. Correlations between the metal contents in samples were investigated by performing correlation tests with SPSS 13.0 for windows.

Trophic ecology and bioindicator potential of the North Atlantic tope shark

Sharks are top marine predators vital in maintaining ecosystem health and food web structure. In order to assess tope shark (Galeorhinus galeus) trophic ecology, stable isotope ratios and trace metal concentrations in muscle tissue were determined, according to size and gender, for 124 individuals caught within the Mid-Atlantic region. Data was complemented and analysed according to previous stomach content information and compared with studies performed in the North East Atlantic. Our results revealed that tope sharks fed at a low trophic level and within a more pelagic-based food web when compared with other North Atlantic regions. MixSIR application reflected its piscivorous diet and study area topography, oligotrophic waters and volcanic nature, suggesting the occurrence of a Mid-Atlantic tope shark population. Considering a non-anthropogenic volcanic source for observed metal contents, the results reflect bioaccumulation and suggest biomagnification processes for As and Hg. These metals exceeded legislated maximum limits for some countries with a maximum of 28.98±1.26 and 0.57±0.01mgkg−1 wet weight, respectively, increasing significantly with size for both males and females. Conversely, Cr, Rb and Zn were relatively stable while Cd and Pb were not detected. Hg and Se were strongly correlated, suggesting a Se toxicity mitigation role. Given the tope shark travel capacity and the results obtained, the species may be used as a Mid-Atlantic bioindicator of environmental quality.

The effect of exercise training and water extract from propolis intake on the antioxidant enzymes activity of skeletal muscle and liver in rat.

[Purpose]In this study, the authors have intended to investigate the effects that the exercise training and the intake of the water extract from propolis have on the activity of antioxidant enzymes.[Methods]For this purpose, the exercise training (70% VO2max treadmill running exercise for 60min)of 5 times per week for six weeks and the intake (50mg/kg/day) of the water extract from propolis were performed by separating the experimental animals (SD rats, n=32) into CON(n=8) group, CON+Ex(n=8), PA(n=8), and PA+Ex(n=8).[Results]As a result, the following conclusions were obtained: The concentration of the blood glucose and insulin of the CON+Ex group and PA+Ex group which are the exercise parallel group were significantly decreased in comparison with the control group, whereas if comparing the glycogen concentration in skeletal muscle and liver tissue between the exercise parallel group and the CON group, the former showed significantly high value in comparison with the latter (p < .05). In the case of the activity of the antioxidant enzyme in the skeletal muscle and the liver tissue, the activities of SOD, GPX and CAT in the gastrocnemius muscle tissue of the experimental animals showed significantly high value in PA+Ex group in comparison with other experimental groups (p < .05). In addition, the SOD activity in the liver tissue showed that only PA+Ex group was significantly increased, whereas GDX activity showed significantly higher value in CON+Ex group and PA group than CON group (p < .05). However, the activity of CAT in the liver tissue showed that there is no difference between the experimental groups. As a result that measured the concentration of MDA in order to evaluate the damage level of the tissue by oxygen free radicals, the difference between the groups in the liver tissue was not shown, while it was shown that only PA+Ex group in the skeletal muscle tissue was significantly decreased in comparison with other experimental groups (p < .05).[Conclusion]Taken together the above findings, it is considered that the parallel treatment of the exercise training and the water extract from propolis can not only increase the use of glycogen of the skeletal muscle and liver tissue, but also it can give the effect to suppress the creation of active oxygen by inducing the activity of the antioxidant enzyme in the body, and in the future, the possibility as the exercise supplements and the antioxidant of the water-soluble propolis are expected.

Mercury Concentrations in Tissues of Colombian Slider Turtles, Trachemys callirostris, from Northern Colombia

This study determined the total mercury (THg) concentrations in pectoral muscle, blood and carapace tissue in turtles collected from Magangué and Lorica, Colombia. THg concentrations in μg/g (wet weight) were 0.39±0.16 in muscle, 0.15±0.08 in carapace and 0.07±0.03 in blood for turtles from the Magdalena River and 0.25±0.18 in muscle, 0.14±0.09 in carapace and 0.06±0.04 in blood for turtles from the Sinú River. Twenty-nine and ten percent of turtle muscle samples from Magangué and Lorica, respectively, exceeded the consumption advisory limit of 0.5 μg Hg/g for fish. There was a significant correlation between carapace length and THg levels for this specie, depending on the sample site. In addition, a significant correlation was observed in THg concentrations in carapace and muscle. However, significant differences were observed in the THg levels between the two study locations, with turtles caught in the Magdalena River having higher levels of THg.

The Effect of Fish Size, Age and Condition Factor on the Contents of Seven Essential Elements in Anguilla anguilla from Tersakan Stream Mugla (Turkey)

The correlation coefficients between age, weight, total length and condition factor (K) and trace metals (Co, Cr, Cu, Fe, Mn, Ni and Zn) in Anguilla anguilla were determined. Totally 160 fish samples were collected from Tersakan Stream (Mugla) between September 2011 and August 2012. Highly significant (P<0.01) relationship between trace metal concentrations in fish muscle and age, weight, total length and condition factor (K) was found. Significantly positive relationship among trace metals (Co, Cr, Cu, Fe, Mn, Ni and Zn) and fish age, weight and total length was observed, while all trace metal concentrations were negatively correlated with fish condition factor (K). The comparison of trace metal concentrations in the muscle of Anguilla anguilla with the tolerable values indicated that the trace metal concentrations in muscle tissue did not exceed the WHO/FAO, EPA and IAEA–407 guidelines.

Bioaccumulation of Heavy Metals in Fish Sourced from Environmentally Stressed Axis of River Niger: Threat to Ecosystem and Public Health

Pollution of freshwater ecosystems is alarmingly becoming high in Nigeria with attendant public health effects on the dependent populations. Fish, a source of protein with pronounced placement on local food menu is now considered an important dietary threat of heavy metal toxicity via consumptions. Bioaccumulation of heavy metals (copper, zinc and lead) in Silver catfish (Schilbe intermedius) from River Niger was conducted. The Fish samples were collected from different sites of Onitsha axis of the River Niger owing to their environmental stresses. Samples were analyzed for heavy metal (copper- Cu, zinc- Zn, and lead- Pb) concentrations in muscle tissues using the Atomic Absorption Spectrophotometer (AAS) and compared with Food and Agriculture Organization safe limits. Margin of exposure (MOE) was estimated to measure the potential public health risk of consuming the contaminated fish. The concentrations of heavy metals (Cu- 8.92±4.748, Zn- 0.36±0.249, and Pb- 2.689±1.505) observed were significant (P Pb>Zn. Statistical Pearson moment correlation analysis showed that the concentrations of heavy metals detected were independent of the weight of sampled fish for zinc but was positively correlated for copper and lead. Relating the mean metal concentrations obtained in the study with Food and Agriculture Organization standard for fish muscles indicated that mean concentrations of copper, zinc and lead are far above safe margins for human consumption except the fish sourced from sites A4 and A9 for lead and zinc, respectively. Margin of exposure was below one and tentatively considered not to be of risk to public health. However, there is considerable contamination of the Silver catfish from the River Niger with heavy metals. It is recommended that substantial attention be paid to the heavy metal levels in freshwater fishes from the river. Measures should be put in place to regulate the indiscriminate dredging activities, discharge of raw sewage and industrial effluent into the river and regular public health check on the level of heavy metals among the populace in the communities that border the area should be employed.

Pharmacokinetic Profile and Muscle Residue Elimination of Tilmicosin after Oral Administration in Crucian Carp (Carassius auratus)

The aim of this study was to investigate the pharmacokinetics and muscle tissue residue elimination of tilmicosin (TLM) in crucian carp (Carassius auratus) at water temperature of 26±1°C after administration of TLM at three different doses. The crucian carp were randomly divided into two treatment groups and a control group. TLM was administered at two different doses to the treatment groups. Group 1 received a single orally administered dose of TLM at the rate of 50mg/kg body weight, group 2 received three orally administered doses of TLM at the rate of 50 mg/kg body wt. on three consecutive days and Group 3 (the control group) received a normal, drug free diet (0 TLM). TLM concentrations in plasma and muscle tissue were analyzed with ultra highperformance liquid chromatography (UPLC, Waters, USA). Using the 3p97 software, the data of pharmacokinetics was conformed to a two-compartment model. The absorption rate constant (Ka) and absorption half-life (t1/2 kα) of TLM were 1.99 h and 0.349 h, respectively. The distribution half-life (t1/2α) and elimination half-life (t1/2β) of TLM were 2.87 h and 39.89 h, respectively. The maximum concentration (Cmax) of TLM in plasma was 19.36 μg/ml and the time to peak concentration (Tp) was 1.27 h. The area under the plasma concentration-time curve (AUC) was 240.326 µg·h/ml. The distribution volume (Vd/F) of TLM was calculated as 1.968 l/kg. for determination of the muscle residue elimination of TLM used by oral administration at a dosage of 50 mg/kg body weight per day for 3 days of TLM. The results revealed that the elimination of TLM in the crucian carp muscle tissue has a long half-life time of 3.12 d. Based on the above residues, we suggest the withdrawal time should be at least 33 days, calculated by the equation MRL=C0 ek(WDT).

Physiologically based pharmacokinetic modeling of POPs in Greenlanders

Human exposure to persistent organic pollutants (POPs) and the potential health impact in the Arctic far from the emission sources have been highlighted in numerous studies. As a supplement to human POP biomonitoring studies, a physiologically based pharmacokinetic (PBPK) model was set up to estimate the fate of POPs in Greenlandic Inuit's liver, blood, muscle and adipose tissue following long-term exposure to traditional Greenlandic diet. The PBPK model described metabolism, excretion and POP accumulation on the basis of their physicochemical properties and metabolic rates in the organisms. Basic correlations between chemically analyzed blood POP concentrations and calculated daily POP intake from food questionnaire of 118 middle age (18–35years) Greenlandic Inuits from four cities in West Greenland (Qaanaaq: n=40; Qeqertarsuaq: n=36; Nuuk: n=20; Narsaq: n=22) taken during 2003 to 2006 were analyzed. The dietary items included were polar bear, caribou, musk oxen, several marine species such as whales, seals, bird and fish as well as imported food. The contaminant concentrations of the dietary items as well as their chemical properties, uptake, biotransformation and excretion allowed us to estimate the POP concentration in liver, blood, muscle and adipose tissue following long-term exposure to the traditional Greenlandic diet using the PBPK model. Significant correlations were found between chemically analyzed POP blood concentrations and calculated daily intake of POPs for Qeqertarsuaq, Nuuk and Narsaq Inuit but not for the northernmost settlement Qaanaaq, probably because the highest blood POP level was found in this district which might mask the interview-based POP calculations. Despite the large variation in circulating blood POP concentrations, the PBPK model predicted blood concentrations of a factor 2–3 within the actual measured values. Moreover, the PBPK model showed that estimated blood POP concentration increased significantly after consumption of meals. For individuals who had a high internal burden of POPs accumulated over years, the estimated blood levels were less influenced by recent meal intake. The model results also indicated that of the POPs accumulated in the body the concentrations were highest for CB-153 (oxychlordane: 0.6%; DDE and CB-99: 2.9%; HCB: 4.4%; CB-153: 34.5%). Furthermore, the model also estimated a significant internal body POP burden even several years after the mentioned dietetic shift and that contaminant accumulation was 2–6 folds faster than the decay after a shift to a diet low in contaminants. Using the PBPK model approach, we seek to improve the knowledge on contaminant body burden in humans of the Arctic. However, it should be noted that calculations of daily POP intake may be subject to considerable uncertainty due to imprecise information from the dietary interview. Based on these results we suggest that PBPK modeling is implemented as a tool in future human health exposure and effect assessments in Greenland.

Total mercury concentrations in lionfish (Pterois volitans/miles) from the Florida Keys National Marine Sanctuary, USA

Strategies to control invasive lionfish in the western Atlantic and Caribbean are likely to include harvest and consumption. Until this report, total mercury concentrations had been documented only for lionfish from Jamaica, and changes in concentrations with increasing fish size had not been evaluated. In the Florida Keys, total mercury concentrations in dorsal muscle tissue from 107 lionfish ranged from 0.03 to 0.48ppm, with all concentrations being less than the regulatory threshold for limited consumption. Mercury concentrations did not vary consistently with standard lengths or wet weights of lionfish. In 2010, lionfish from the upper Keys had mean concentrations that were 0.03–0.04ppm higher than lionfish from the middle Keys, but mean concentrations did not differ consistently among years and locations. Overall, total mercury concentrations in lionfish were lower than those in several predatory fishes that support commercial and recreational fisheries in Florida.

Reducing Pb poisoning in birds and Pb exposure in game meat consumers: The dual benefit of effective Pb shot regulation

The use of lead (Pb) ammunition in the form of shot pellets has been identified as a Pb exposure risk in wildlife and their human consumers. We explore the hypothesis that Pb shot ban enforcement reduces the risk of avian Pb poisoning as well as Pb exposure in game meat consumers. We assessed compliance with a partial ban on Pb shot commencing in 2003 by examination of 937 waterbirds harvested by hunters between 2007 and 2012 in the Ebro delta (Spain). Prevalence of Pb shot ingestion was determined, as were Pb concentrations in liver and muscle tissue to evaluate the potential for Pb exposure in game meat consumers. Hunted birds with only embedded Pb shot (no steel) declined from 26.9% in 2007–08 to <2% over the following three hunting seasons after ban reinforcement. Pb shot ingestion in mallards decreased from a pre-ban value of 30.2% to 15.5% in the post-ban period. Liver Pb levels were predominantly defined by the presence of ingested shot, whereas muscle levels were defined by the presence of both ingested and embedded shot. Only 2.5% of mallard muscle tissue had Pb levels above European Union regulations for meat (0.1μg/g wet weight) in the 2008–09 season, when Pb shot ingestion prevalence was also at a minimum (5.1%). Effective restrictions in Pb ammunition use have a dual benefit since this reduces Pb exposure for game meat consumers due to embedded ammunition as well as reducing Pb poisoning in waterbirds.

The Influence of Symmetrical Feed:Fast Regimes on Oxytetracycline Uptake and Otolith Score in Yellow Perch

Periods of growth from symmetric feed:fast regimes (i.e., days fed followed by the same number of days fasted) may increase the uptake of oxytetracycline (C22H24N2O9 .HCL[OTC]) compounds in fishes; however, little empirical data exists. Therefore, we experimentally determined if such feeding regimes influenced the concentration of OTC incorporated in muscle and skeletal (e.g., otoliths) tissues. Individually-reared female and batch-reared (male and female), age-1 yellow perch Perca flavescens were subjected to one of four experimental feeding regimes: control (i.e., fed daily), D2 (i.e., 2d feed, 2d deprivation), D6, or D12 symmetrical feed:fast regimes. Following several feeding cycles on these feeding regimes, fish were submersed in a 600mg/L buffered OTC solution; otoliths and muscle tissue were excised and processed to determine OTC uptake via mark quality and concentrations. Ranked otolith scores (mark quality) were significantly lower for the D2 feeding regime than control, D6, and D12 scores for both individual and batch trials suggesting that frequent food deprivation restricts osteogenesis, while daily or extended feeding periods contribute to osteogenesis. In batch-reared fish, total OTC and 4-epioxytetracycline peak concentrations in muscle tissue did not significantly differ among treatments but were significantly greater for smaller individuals within treatments suggesting that the OTC uptake and elimination response is mechanistically related to higher gill ventilation volume and gastric ingestion rate of small fish providing increased chemical assimilation and decreased clearing time following OTC immersions. Increased otolith mark quality derived from such feeding protocols may be of particular interest to fisheries managers conducting stock contribution assessments of yellow perch, but this induction strategy may apply to other species as well as therapies for hatchery stocks.

Effects of organic selenium supplementation on growth performance, nutrient utilisation, oxidative stress and selenium tissue concentrations in broiler chickens

The effects of organic selenium (Se) supplementation of diets for broiler chickens were evaluated in the present study. Broiler diets had average background Se concentrations of 0.36 mg/kg Se (control diet) and were supplemented with two organic Se sources, namely BiOnyc® Tor-Sel (selenohomolanthionine = SH) and Alltech’s Sel PlexTM (selenomethionine = SM); their addition increased dietary selenium concentrations by an average of 0.57 mg/kg Se. Their effects on growth performance, nutrient utilisation and oxidative status of broiler chickens were determined. Growth performance was very similar across all dietary treatments; in contrast, significant differences in nutrient utilisation were observed. The N-corrected apparent metabolisable energy value for the control group (14.14 MJ/kg) and SH (14.15 MJ/kg) diet was significantly (P &lt; 0.01) higher than that for the SM (13.64 MJ/kg) diet. Alternatively, N retention with the SM (68.4%) diet was significantly (P &lt; 0.005) higher than that for the control (65.2%) and SH (64.5%) diets. Neither of the Se sources influenced plasma concentrations of reactive oxygen metabolites, biological antioxidant potential and advanced oxidation protein products. The activity of glutathione peroxidase, superoxide dismutase in both plasma and tissues samples and the concentration of plasma glutathione were increased by SH and SM compared with the control group. Our findings suggest that SH and SM improved the antioxidant status of broilers by elevating activities of antioxidant enzymes and concentrations of antioxidant. Both Se supplements significantly (P &lt; 0.001) increased Se concentrations in liver and muscle, and in liver tissue there was no statistical difference between the two supplements. However, SH generated significantly higher Se concentrations in muscle tissue (0.283 versus 0.257; P &lt; 0.005) than did SM. In summary, SH was at least the equivalent to SM as a source of organic Se for broiler chickens under the conditions of the present feeding study. This is reflected in the outcome that SH generated significantly higher Se concentrations in muscle tissue than did the alternative Se supplement.

Mercury speciation in fish muscles from major Czech rivers and assessment of health risks

The aim of this work was to determine the mercury and methylmercury content in muscle tissue of chub (Leuciscus cephalus L.), to assess the health risks of eating the fish and to determine the number of fish meat servings that are suitable for weekly consumption. Total mercury concentrations were determined using a single-purpose atomic absorption spectrophotometer AMA 254. Methylmercury concentrations were determined by gas chromatography. The location where the highest total mercury concentrations in fish muscle tissues were found was the Vltava – Vraňany (0.236±0.1001mg/kg−1), and the highest methylmercury concentration was found at the Labe – Obříství (0.231±0.1056mg/kg−1). The conclusion based on the data ascertained is that the locations from which the lowest number of fish meat servings can be eaten are the Vltava – Vraňany and the Labe – Obříství. The results of this study helped evaluate contamination levels of rivers that flow out of the Czech Republic.

Effects of feeding level and sexual maturation on fatty acid composition of energy stores in diploid and triploid rainbow trout (Oncorhynchus mykiss)

Sexual maturation is an energy demanding, physiological process that alters growth efficiency and compromises muscle quality in many food-fish species. Lipid mobilization supplies energy required for this process. To study the effect of ration level on fatty acid composition, diploid (2N) rainbow trout, approaching ovulation, were fed at 0.25 and 0.50% of tank biomass/day and to apparent satiation (~0.75% of tank biomass/day). In addition, triploid (3N) female trout, which exhibit only minimal ovarian development, were fed at 0.50% of tank biomass/day. The primary objective of this study was to determine effects of ration level on fatty acid composition in different lipid compartments (muscle, visceral adipose tissue, liver, and gonad) during sexual maturation. Lower feeding levels produced smaller fish, but did not affect the onset of sexual maturation. Higher feeding levels resulted in fish muscle with higher relative amounts of saturated fatty acids (SFAs), but monounsaturated fatty acids (MUFAs) and polyunsaturated fatty acids (PUFAs) were not affected by ration level. While ration level affected the fatty acid profile of each of the four tissues analyzed, the number of fatty acids affected was greatest in white muscle. An additional objective was to determine differences in the fatty acid composition of energy stores during maturation in female rainbow trout that were fed at a moderately restricted feeding level (0.50% of tank biomass/day). These differences were determined by comparing mature 2N to sterile 3N females of the same age. Diploid muscle contained higher amounts of PUFAs (44.4±1.0%) than 3N muscle (39.7±0.8%). Saturated fatty acids were in the highest concentrations in muscle and visceral adipose tissue, and 2N liver contained more PUFAs and fewer MUFAs than 3N liver; however these values are relative values. In general, fatty acids affected by ration level were not the same as fatty acids affected by ploidy. Triploid fatty acid profiles did not mimic those of the satiation fed group; which was expected if 3N fish were simply consuming excess energy. Both 2N and 3N muscle fatty acid profiles were similar to that of the diet, except muscle had lower amounts of PUFA precursors (18:3n-3 and 20:5n-3) and higher relative amounts of their product (22:6n-3). Also, 2N muscle had higher 16:1 and 3N muscle had higher 16:0 compared to the diet. It is unclear if these differences are hormonally driven or if there are other physiological dissimilarities between 2N and 3N trout causing these differences. Overall, our data suggest that 2N and 3N fatty acid metabolism is regulated differently.

Monitoring mercury in green sea turtles using keratinized carapace fragments (scutes)

The green sea turtles are facing a very high risk of extinction in the wild and the impacts of heavy metals contamination contributes with the decline of their populations. It is very important to assess noninvasive and nonlethal methods for monitoring Hg contamination in sea turtles. Thus, Hg concentrations were measured in keratinized fragments (scutes) and internal tissues of green sea turtles from the Ceará coast to test the usefulness of scutes as a monitoring subject for sea turtles. A significantly positive correlation was found between Hg concentrations in muscle and scutes, which demonstrate that scutes can be used as a predictive matrix of Hg concentration in muscle tissue of green sea turtles.

Metal accumulation in the greentail prawn, Metapenaeus bennettae, in Sydney and Port Hacking estuaries, Australia

Metal concentrations of the inshore greentail prawn, Metapenaeus bennettae, and surface sediments from locations within Sydney estuary and Port Hacking (Australia) were assessed for bioaccumulation and contamination. The current study aimed to assess metal concentrations in prawn tissue (tail muscle, exoskeleton, hepatopancreas and gills), relate whole body prawn tissue metal concentrations to sediment metal concentrations and animal size, as well as assess prawn consumption as a risk to human health. Metal concentrations were highest in sediment and prawns from contaminated locations (Iron Cove, Hen and Chicken Bay and Lane Cove) in Sydney estuary compared with the reference estuary (Port Hacking). Concentrations in sediments varied considerably between sites and between metals (As, Cd, Cr, Cu, Ni, Pb and Zn), and although concentrations exceeded Interim Sediment Quality Guideline-Low values, metals (As, Cd, Cr, Cu, Ni, Pb and Zn) were below Australian National Health and Medical Research Council human consumption guidelines in prawn tail muscle tissue. Metal concentrations in prawn tail muscle tissue were significantly different (p ≤ 0.05) amongst locations for Pb, Zn and Cd, and metal concentrations were generally highest in gills tissue, followed by the hepatopancreas, exoskeleton and tail muscle. The exoskeleton contained the highest Sr concentration; the hepatopancreas contained the highest As, Cu and Mo concentrations; and the gills contained the highest Al, Cr, Fe and Pb concentrations. Concentrations of Pb, As and Sr were significantly different (p ≤ 0.05) between size groups amongst locations.

Screening Blood Samples to Estimate When Oxytetracycline Residues Exceed Regulatory Tolerances in Poultry Muscle

Presence of antibiotic residues in edible animal products is a human food safety concern. To address this potential problem, many governments sample edible tissues, such as muscle, to monitor for residues. Alternatively, antibiotic residue concentrations could be screened in blood which is readily available during carcass processing. To determine if blood concentrations are predictive of muscle concentrations, 252 market aged broilers were dosed with Oxytetracycline (OTC) in water at three doses: the maximum OTC approved dose for broilers (800 mg/gal) or five or ten times that dose. Blood and muscle samples were collected before initial dosing (0 hour, controls), during dosing at 1, 3, 6, 12, 24, 48, 96 or 144 hours and at 12, 24, 36, 48 or 60 hours after drug withdrawal. Concentrations in blood and muscle tissues followed similar time: concentration patterns, peaking 24 hours after initial dosing (396±9 vs. 557±37 ppb; 443±48 vs. 1846±58 ppb or 2447±67 vs. 3210±36 ppb for the 1, 5 or 10x doses in blood vs. muscle, respectively) and declined rapidly after withdrawal. These data suggest blood samples may be used to predict OTC concentrations in muscle as a screening procedure for OTC residues in poultry.

An Assessment of Heavy Metal Bioaccumulation in Asian Swamp Eel, Monopterus albus, During Plowing Stages of a Paddy Cycle

Livers and muscles of swamp eels (Monopterus albus) were analyzed for bioaccumulation of heavy metals during the plowing stage of a paddy cycle. Results showed heavy metals were bioaccumulated more highly in liver than muscle. Zinc (Zn) was the highest bioaccumulated metal in liver (98.5±8.95μg/g) and in muscle (48.8±7.17μg/g). The lowest bioaccumulated metals were cadmium (Cd) in liver (3.44±2.42μg/g) and copper (Cu) in muscle (0.65±0.20μg/g). In sediments, Zn was present at the highest mean concentration (52.7±2.85μg/g), while Cd had the lowest mean concentration (1.04±0.24μg/g). The biota-sediment accumulation factor (BSAF) for Cu, Zn, Cd and nickel (Ni) in liver tissue was greater than the corresponding BSAF for muscle tissue. For the three plowing stages, metal concentrations were significantly correlated between liver and muscle tissues in all cases, and between sediment and either liver or muscle in most cases. Mean measured metal concentrations in muscle tissue were below the maximum permissible limits established by Malaysian and U.S. governmental agencies, and were therefore regarded as safe for human consumption.

Arsenic and other trace elements in two catfish species from Paranaguá Estuarine Complex, Paraná, Brazil

Concentrations of arsenic and four additional trace elements (Cu, Cr, Ni, and Zn) were determined by inductively coupled plasma-optical emission spectrometry in the muscular tissue of the yellow catfish (Cathorops spixii) and the urutu catfish (Genidens genidens) from Paranaguá Estuarine Complex, Brazil (PEC). The PEC can be characterized by an environment of high ecological and economic importance in which preserved areas of rainforest and mangroves coexist with urban activities as ports and industries. The average concentrations (in milligram per kilogram dry weight) of elements in the muscle tissue of C. spixii are as follows: Zn (31), As (17), Cu (1.17), Cr (0.62), and Ni (0.28). Similar concentrations could be found in G. genidens with exception of As: Zn (36), As (4.78), Cu (1.14), Cr (0.51), and Ni (0.14). Fish from the geographic northern rural region (Guaraqueçaba-Benito) display higher As concentrations in the muscle tissues than fish found in the south-western (urban) part of the PEC. An international comparison of muscle tissue concentrations of trace elements in fish was made. Except for Ni in C. spixii, a tendency of decrease in element concentration with increasing size (age) of the fish could be observed. According to the National Health Surveillance Agency of Brazil, levels of Cr and As exceeded the permissible limits for seafood. An estimation of the provisional tolerable weekly intake of As was calculated with 109% for C. spixii and with 29% for G. genidens.

Measuring Potassium in Muscle Tissue Utilizing an Atomic Absorption Spectrometer Validation of an Adaptation for a Whole-body Potassium Counting Method

Potassium is a cation important for a properly functioning body. It is especially significant for nerves, kidneys, and muscles. The concentration of potassium ions in muscle tissue was determined using an atomic absorption spectrometer operating in emission mode. The meat samples were flash frozen using liquid nitrogen, further ground using a mortar and pestle and then digested by immersing the processed meat in a hydrochloric acid solution. The potassium concentrations in muscle tissue were found to range from 2.76 – 4.66 g K+/kg of beef sample.