Different Tissues Of Fish Research Articles

Multiple biomarkers responses in juvenile rainbow trout, Oncorhynchus mykiss, after acute exposure to a fungicide propiconazole

In this study, the toxic effects of propiconazole (PCZ), a triazole fungicide present in aquatic environment, were studied in juvenile rainbow trout, Oncorhynchus mykiss, by acute toxicity test with the concentration of 5.04 mg/L (96 h LC50). Morphological indices, hematological parameters, liver xenobiotic-metabolizing response, and tissue antioxidant status were evaluated. Compared with the control group, fish exposed to PCZ showed significantly higher Leuko, PCV, MCHC, and hepatic EROD, and significantly lower MCV. CF and HSI were not significantly different among groups. SOD, CAT, GPx, and GR activities increased significantly in liver of experimental groups, but decreased significantly in gill. In general, antioxidant enzyme activity in intestine was less evident than in liver. Oxidative stress indices (levels of LPO and CP) were significantly higher in gill. Additionally, through chemometrics of all parameters measured in this study, two groups with 67.29% of total accumulated variance were distinguished. In short, the physiological and biochemical responses in different tissues of fish indicated that PCZ-induced the stressful environmental conditions. But according to PCZ residual status in the natural environment, more long-term experiments at lower concentrations will be necessary in the future. © 2011 Wiley Periodicals, Inc. Environ Toxicol, 2013.

Assessment of genotoxic and mutagenic effects of chlorpyrifos in freshwater fish Channa punctatus (Bloch) using micronucleus assay and alkaline single-cell gel electrophoresis

Chlorpyrifos (CPF) is the single largest selling agrochemical that has been widely detected in surface waters in India. The studies on long-term genotoxic effects of CPF in different tissues of fish using genotoxic biomarkers are limited. Therefore, in the present study DNA damage by CPF in freshwater fish Channa punctatus using micronucleus (MN) and comet assays was investigated. The LC 50 – 96 h of CPF was estimated for the fish in a semi-static system. On this basis of LC 50 value sublethal and nonlethal concentrations were determined. The DNA damage was measured in lymphocytes and gill cells as the percentage of DNA in comet tails and micronuclei were scored in erythrocytes of fishes exposed to above concentrations of CPF. In general, significant effects for both the concentrations and time of exposure were observed in treated fish. It was found that MN induction in the blood was highest on day 14 at 203.0 μg/l of CPF. The highest DNA damage was observed on day 5, followed by a gradual non-linear decline in the lymphocytes and gill cells. The study indicated MN and comet assays to be sensitive and rapid methods to detect mutagenicity and genotoxicity of CPF and other pollutants in fishes.

Long-term genotoxic effect of monocrotophos in different tissues of freshwater fish Channa punctatus (Bloch) using alkaline single cell gel electrophoresis

Monocrotophos, commonly known as azodrin, is one of the organophosphate pesticides extensively used in agricultural practices throughout the world. However, little information is available on its long-term genotoxic effects in different tissues of fish using genotoxicity biomarkers. The objective of the present study was to detect DNA damage, induced by monocrotophos in freshwater teleost fish Channa punctatus using the comet assay. The LC 50-96 h value of technical-grade monocrotophos was estimated for the fish species in a semi-static system. On the basis of the LC 50 value, the sublethal and nonlethal concentrations were determined. The DNA damage was measured in the gill, kidney and lymphocytes as the percentage of DNA in comet tails of fish exposed to different sublethal and nonlethal concentrations of monocrotophos. In general, significant effects ( P < 0.01) from both concentration and time of exposure were observed in exposed fish. It was found that the tissues at all concentrations exhibited the highest DNA damage on day 4, after which there was a decline in percentage tail DNA. The comparison of DNA damage among tissues at different concentrations indicated that the gill cells were more sensitive to the pesticide than the kidney cells and lymphocytes. This study also explored the utility of the comet assay for in vivo laboratory studies using fish for screening the genotoxic potential of various agents.

Pesticide residues and reproductive dysfunction in different vertebrates from north India

Organochlorines (isomers of hexachlorocyclohexane – HCHs and metabolites of dichlorodiphenyltrichloroethane – DDTs, aldrin and endosulfan) and organophosphate (chlorpyrifos) insecticide residues were investigated by gas liquid chromatography in the blood of fish, chick, goat and man. The plasma levels of testosterone (T) and estradiol-17β (E2) was measured by radioimmunoassay in the catfish Rita rita captured from unpolluted reference site and polluted river Gomti during prespawning phase. Results indicated that in R. rita the ΣDDT, ΣHCH, endosulfan, aldrin, chlorpyrifos in blood levels were in preferential order (ΣDDT > ΣHCH > endosulfan > aldrin > chlorpyrifos) of their bioaccumulation. The blood levels of ΣHCH and ΣDDT also showed high levels in chick, goat and man, and preferential order of bioaccumulation was goat > chick > man > fish. The ΣDDT also showed preferential order (man > chick > goat > fish) of bioaccumulation. Among the different tissues of fish (blood, liver, brain and ovary) the ΣDDT was very high as compared to ΣHCH as well as the rest of tissues which was very selective bioconcentration in different tissues of fish during prespawning phase. The gonado-somatic index, T and E2 declined in the catfish captured from polluted river when compared with the catfish captured from reference site affecting reproductive physiology. Our results indicated that increase of insecticides in blood level in vertebrates causes reproductive dysfunction and suggested that for human beings food like fish, chick and goat containing beyond permissible limit of insecticides must be avoided.

Genotoxicity assessment of acute exposure of chlorpyrifos to freshwater fish Channa punctatus (Bloch) using micronucleus assay and alkaline single-cell gel electrophoresis

Chlorpyrifos (O,O-diethyl O-3,5,6-trichloro-2-pyridylphosphorothioate) is one of the organophosphate pesticides widely used in agricultural practices throughout world and irreversible inhibitor of cholinesterase in all animal species. Limited efforts have been made to study acute genotoxic effects of chlorpyrifos (CPF) in different tissues of fish using genotoxic biomarkers. Therefore, the present investigation was aimed to study the induction of DNA damage by CPF in freshwater teleost fish Channapunctatus using micronucleus assay (MN assay) and alkaline single-cell gel electrophoresis (comet assay). The value of LC50 – 96h of CPF was determined as 811.98μgl−1 for C. punctatus, in a semi-static system and on the basis of LC50 value three acute concentrations viz., 203, 406 and 609μgl−1 were determined. The fishes were exposed to the different concentrations of CPF for 96h and samplings were done at regular intervals for assessment of the MN frequencies and DNA damage. In general, significant effects (P<0.01) from both concentrations and time of exposure were observed in exposed fishes. It was found that the micronucleus induction was highest on 96h at all concentrations in the peripheral blood. Similar trend was observed for the DNA damage measured in terms of the percentage of tail DNA in the lymphocyte and gill cells. This study explored the combined use of micronucleus assay and comet assay for in vivo laboratory studies using fresh water fish for screening the genotoxic potential of xenobiotics.

Microcystin accumulation in liver and muscle of tilapia in two large Brazilian hydroelectric reservoirs

The objective of this study was to measure levels of the toxin microcystin in different tissues of fish known to feed on cyanobacteria during toxic bloom events. Wild Nile and redbreast tilapia ( Oreochromis niloticus and Tilapia rendalli) were sampled from the catch of artisanal fishermen at eutrophic stations of Funil and Furnas reservoirs in southeastern Brazil. Phytoplankton communities in the two reservoirs were quite different taxonomically, but not dissimilar in microcystin content (200 μg g dry weight (DW) seston −1 at Funil, 800 μg gDW seston −1 at Furnas). All of the 27 fish sampled contained microcystin, ranging from 0.8 to 32.1 μg g liver −1 and from 0.9 to 12.0 ng g muscle −1. Most microcystin variants found in seston were also found in fish liver . T. rendalli had the lowest concentration in both tissues when compared to O. niloticus. In both reservoirs, one of every four fish sampled, always O. niloticus, had a level of microcystins beyond the World Health Organization tolerable daily intake (8 ng g tissue −1) and represented a risk for consumers. It is possible that closer study of inter-species variability in toxin burden in cyanobacteria-impacted water bodies will permit the development of guidelines for fish consumption that will better protect public health.

Studies on the Genotoxicity of Endosulfan in Different Tissues of Fresh Water Fish Mystus vittatus Using the Comet Assay

Endosulfan, a widely used organochlorine pesticide, is readily bio-accumulative in fishes and can be indirectly harmful to human populations. Limited efforts have been made to study long-term genotoxic effects of endosulfan in different tissues of fish using gentoxicity biomarkers. Therefore, the current investigation was undertaken to detect single-cell DNA strand breaks induced by endosulfan in the fresh water teleost fish Mystus vittatus using the comet assay. The LC(50) value of technical grade endosulfan was first determined for the fish species in a semistatic system, and on the basis of the LC(50) value, the sublethal and nonlethal concentrations were determined. The DNA damage was measured in gill, kidney, and erythrocytes as the percentage of DNA in comet tails of fish specimens exposed to the sublethal and nonlethal concentrations of endosulfan. In general, significant effects (p < 0.01) from both concentration and time of exposure were observed in exposed fishes. It was found that all the tissues at all concentrations exhibited the highest DNA damage on day 1, after which there was a nonlinear decline in the percentage of tail DNA. The comparison of DNA damage among the tissues at different concentrations could not show the sensitivity of particular tissue to endosulfan. The current study explored the utility of the comet assay for in vivo laboratory studies using fish species to screen the genotoxic potential of chemical agents.

Toxicity ranking of estuarine sediments on the basis of Sparus aurata biomarkers

Sparus aurata biomarkers were used to rank sediments from the Sado River estuary (Portugal) according to their toxicity. Initially, the activities of liver ethoxyresorufin-O-deethylase, liver and gill glutathione S-transferases, muscle lactate dehydrogenase, and brain acetylcholinesterase were tested in a laboratory bioassay with the reference compound benzo[a]pyrene. Enzymatic activities were determined in different tissues of fish exposed for 48, 96, or 240 h to three concentrations of benzo[a]pyrene (25, 50, and 100 microg/L). Induction of liver ethoxyresorufin-O-deethylase was observed at all the exposure periods and concentrations, suggesting a continuous response of this system to toxicant exposure. Induction of liver glutathione S-transferases activity was only observed after 240 h of exposure, whereas gill glutathione S-transferases activity was significantly inhibited at all the exposure periods, suggesting a direct or indirect effect of the toxicant on these enzymes. Inhibition of lactate dehydrogenases activity was only observed after 96 h of exposure to 25 microg/L of benzo[a]pyrene. No significant effects were observed on acetylcholinesterase activity, suggesting that cholinergic function of S. aurata is not affected by benzo[a]pyrene. In a second phase, fish were exposed for 240 h to sediments collected at five sites of the Sado River estuary, and the same biomarkers were analyzed. For all the enzymes assayed, significant differences among sites were found. In this study, the battery of biomarkers used allowed to discrimination among sites with different types of contamination, levels of contamination, or both, after multivariate data analysis. Discrimination of sites was similar to the ranking provided by a more complex and parallel study (including chemical analysis of sediments, macrobenthic community analysis, amphipod mortality toxicity tests, and sea urchin abnormality embryo assays), suggesting its suitability to evaluate the toxicity of estuarine sediments.

Water quality affects SDH activity, protein content and RNA:DNA ratios in fish ( Catla catla, Labeo rohita and Oreochromis mossambicus) raised in ponds of a sewage-fed fish farm

The spatial and seasonal variability of the respiratory enzyme succinate dehydrogenase and the protein content were examined in different tissues of fish cultured in three ponds along the effluent gradient of a sewage-fed fish farm. Indian major carp Catla catla (150–230 g) and Labeo rohita (60–190 g) cultured in both the middle and last points of the sewage effluent (stocking pond 1) and (stocking pond 4) and Oreochromis mossambicus (50–160 g), a naturally growing fish of the inlet (facultative pond) and the out let of the sewage effluent (stocking pond 4) were procured every month during the period of January–December, 2005 and were subjected to determination of succinate dehydrogenase activity, total protein, DNA and RNA contents from gill, liver and muscle tissue respectively. The SDH activity of all three test fishes ( Catla catla, Labeo rohita and Oreochromis mossambicus) was reduced significantly (ANOVA; P < 0.05) when cultured in SP-4 compared to SP-1 in the case of Catla catla and Labeo rohita and in facultative pond in the case of Oreochromis mossambicus. Conspicuous differences in the SDH activity of fish between the last and first stocking pond or the facultative pond were clearly due to the result of the differences in water quality. There was a direct relationship between SDH activity in gill tissue of any of the fish investigated and ammonia-N concentration of water or water pH. This shows that the respiratory activity of these fishes was strongly affected by the ammonia and pH of water. In other words, this suggests that as the distance from the point source increases, there was a substantial improvement of water quality in the ponds located along the sewage effluent gradient. Evidently, there is a progressive pattern of growth, survival and physiological health of fish and abundance of favorable diversity of food organisms with rich biodiversity.

Distribution, Transformation, and Long-Term Accumulation of Polychlorinated Dibenzo-p-dioxins and Dibenzofurans in Different Tissues of Fish and Piscivorous Birds

The present study monitored 10-year-old fish and piscivorous birds from sites contaminated for many years. The data reflected the results of actual, long-term environmental exposures. The results demonstrate that different tissues of fish have quite different concentrations of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/F). The concentration order of PCDD/F within fish is liver≅egg≅intestine>kidney≅heart>gill≅bladder>muscle>brain. The concentration order of PCDD/F within piscivorous birds was liver>egg≅heart>muscle≅stomach>brain. The results obtained also demonstrate that the accumulation patterns of piscivorous birds and fish are quite different. The tissues of fish and piscivorous birds have different capacities for bioaccumulation and biotransformation of PCDD/F; variable proportions of TEQs were also found throughout their bodies. In fish, toxic equivalency quotient (TEQ): PCDD/F ratios in various tissues ranged from 0.01 to 0.07, whereas in birds the ratios ranged from 0.07 to 0.43. If the concentrations are normalized with lipid content, the results vary less. The effect of different lipid properties is obvious in the case of brain tissue, which is richer in phospholipids.

Distribution of mercury in the soft tissues of the blue tilapia Oreochromis aureus (Steindachner) after acute exposure to mercury (II) chloride

Mercury has no known biological functions in the animal body and is described as an ultratrace element. Consequently, there is no well defined regulatory mechanism present in the animal body and it tends to accumulate readily if available in an animal's environment. Sources of mercury include the chloroalkali industry, the manufacture of electrical equipment, paint, fungicides and dentistry. The use of mercury in the gold mining industry has caused extensive pollution in the Amazon Basin. Whether fish take up organic or inorganic mercury, most of it accumulates in the tissues in the organic form. Most cases of mercury poisoning arising from fish consumption are due to methylmercury because mercury entering the aquatic system rapidly becomes methylated. Minamata disease in humans was first reported in 1956 due to consumption of contaminated fish and shellfish from Minamata Bay. Therefore it is important to monitor the mercury content of fish which are caught or farmed for human consumption. Since many commercial animal feeds contain a fish meal component, monitoring is important from the aspect of contamination of farm animals intended for human consumption. Oreochromis aureus (Steindachner) is a species of tilapia often cultured in ponds and also in cages in North and Latinmore » America. Therefore, it is a suitable model to use for studying the effects of mercury exposure on the distribution of mercury in different tissues of fish. Distribution is important, because different cultures consume different fish organs, not just the muscle portion alone. The tissues which have a high content of mercury will be most dangerous from a toxicological viewpoint. Removal of the tissues known to contain the highest concentrations of mercury would reduce the mercury content of fish meal. Since fish are often species-specific in their responses to heavy metals, it is important to study a species which is actually farmed and cultured as a food fish. 20 refs., 2 tabs.« less

Age-related changes in oxygen consumption by the gill, brain and muscle tissues of Tilapia mossambica peters exposed to dichlorvos (DDVP)

Tissue slices (gill, brain and muscle) of Tilapia mossambica Peters exposed to Dichlorvos were used to study the effect of ageing on O 2 consumption. The O 2 consumption by different tissues of DDVP-exposed fish was weight-specific. Gill showed a higher O 2 consumption value in all age groups than brain and muscle tissues. The correlation of O 2 consumption and body weight exhibited an inverse relationship. O 2 consumption by different tissues of fish of all age groups decreased when exposed to Dichlorvos. The higher rate of O 2 consumption by gill could be attributed to its high metabolic activity. The gill exhibited maximum inhibition of O 2 consumption compared with brain and muscle. The recovery rate in O 2 consumption by muscle after transfer to clean water was greater than that of brain and gill and was inversely related to ageing.

P&lt;sup&gt;32&lt;/sup&gt; S&lt;sup&gt;35&lt;/sup&gt; Ca&lt;sup&gt;45&lt;/sup&gt;及びSr&lt;sup&gt;89&lt;/sup&gt;の魚体内への転移に関する研究

Previous findings in regard to radioactive contamination of fish varied among workers as to kinds, amounts and routes of radioactive elements transferring into different tissues of fish. In the present experiments one of two groups of the gold fish, Carassius autratus, each measuring 2cm. in the length, was reared for periods from one to 264 hours in water containing either one of the folowing isotopes at various concentrations, P32, S35, Ca45, or Sr89. The other, having been left without food for ten days, was reared for the same length of time in the presence of algae, Spirogyra radioactivated with the above isotopes. Radioactivity absorbed directly from the water is indicated in the ratio of the activity of ashed tissues against that of the water, and the activity transferred through the algae, in the ratio against the algae (Tables 1, 2; Figures 2, 3). Of the isotopes taken by the fish of the former group, Ca45 and Sr89 showed the counts, in most cases, stronger than P32 and S35, with the gill giving off the highest count of all the organs examined; while in the latter group, vice versa. The fact that P32 and S35 were more easily transferred into the digestive organs of the latter fish than Ca45 and Sr89 may be explained in the light of findings from electropherogram exmination of the radioactive algae that P32 and S35 were absorbed in higher molecule compounds, whereas the others found in ionic form in the algae.