Biochemical and hematological effects of a titanium dioxide industrial effluent on fish

Anticipatory plastic response of the cellular immune system in the face of future injury: chronic high perceived predation risk induces lymphocytosis in a cichlid fish

Vertebrate cellular immunity displays substantial variation among taxa and environments. Hematological parameters such as white blood-cell counts have emerged as a valuable tool to understand this variation by assessing the immunological status of individuals. These tools have long revealed that vertebrate cellular immune systems are highly plastic and respond to injury and infection. However, cellular immune systems may also be able to anticipate a high risk of injury from environmental cues (e.g., predation-related cues) and respond plastically ahead of time. We studied white blood-cell (leukocyte) profiles in African cichlids Pelvicachromis taeniatus that were raised for 4 years under different levels of perceived predation risk. In a split-clutch design, we raised fish from hatching onwards under chronic exposure to either conspecific alarm cues (communicating high predation risk) or a distilled water control treatment. Differential blood analysis revealed that alarm cue-exposed fish had twice as many lymphocytes in peripheral blood as did controls, a condition called lymphocytosis. The presence of a higher number of lymphocytes makes the cellular immune response more potent, which accelerates the removal of invading foreign antigens from the bloodstream, and, therefore, may be putatively beneficial in the face of injury. This observed lymphocytosis after long-term exposure to conspecific alarm cues constitutes first evidence for an anticipatory and adaptive plastic response of the cellular immune system to future immunological challenges.

Genetic, reproductive and oxidative damage in mice triggered by co-exposure of nanoparticles: From a hypothetical scenario to a real concern

Humans are potentially exposed to multiple nanoparticles kinds through nanotechnology-based consumer products. There is insufficient data on the in vivo toxicity of nanotechnology products, as well as no data on the possible toxicity, including genotoxicity and reproductive toxicity of co-exposure to different kind of nanoparticles. In this work, solid lipid nanoparticles (SLNs) and superparamagnetic iron oxide nanoparticles (SPIONs) were selected for evaluation of a hypothetical condition of in vivo co-exposure. Genotoxicity of SPIONs and SLNs was performed separately and in 1:1 mixture in mice. Bone marrow micronucleus assay, sperm morphology test, and sperm count were carried out. Also, the serum ALT and AST activities; and hematological parameters of the treated mice were analyzed. The results showed a significant increase (p < 0.05) in micronucleated polychromatic erythrocytes (MNPCE) and nuclear abnormalities (NA) in SPIONs, SLNs and their mixture treated mice. The mixture induced the highest frequency of MNPCE and NA. A similar result was observed in the sperm morphology test, with the mixture inducing the highest sperm abnormalities, followed by SLNs and the least by SPIONs. Significant alteration to RDW, MCHC, MCV, GRAN, and platelets, as well as increased activities of serum AST were observed in the mice treated with a mixture of the two kinds of nanoparticles. Calculation of interaction factor showed a possible synergistic effect between SPIONs and SLNs in MNPCE, NA and sperm morphology studied. Even as a hypothetical scenario of co-exposure to SLNs and SPIONs, this study showed, for the first time, that co-exposure to SPIONs and SLNs is more genotoxic to somatic and germ cells than their individual exposure.

Ecological risk assessment of silicon dioxide nanoparticles in a freshwater fish Labeo rohita: Hematology, ionoregulation and gill Na(+)/K(+) ATPase activity

The fate and effect of nanomaterials in the environment has raised concern about their environmental risk to aquatic organisms. Silica nanoparticles (SiO2-NPs) find its uses in various fields and are inevitably released into the environment. However, the ecotoxicological effects of SiO2-NPs on the freshwater fish remain poorly understood. The aim of this study was to evaluate the effect of different concentrations (1, 5 and 25mgL(-1)) of SiO2-NPs on certain hematological, ionoregulatory and enzymological profiles of a freshwater teleost fish Labeo rohita. Hematological parameters such as hemoglobin (Hb), hematocrit (Hct), red blood cells (RBC), white blood cells (WBC), mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH) and mean corpuscular hemoglobin concentration (MCHC) values were altered in SiO2-NPs treated groups. Likewise, plasma electrolytes such as plasma sodium (Na(+)), potassium (K(+)) and chloride (Cl(-)) levels and Na(+)/K(+) ATPase activity in gill of SiO2-NPs treated groups were altered in all concentrations throughout the study period (96h). The alterations of these parameters were found to be dependent on dose and exposure period. The results of the present study indicate that the alterations of these parameters may relate to physiological stress system to SiO2-NPs toxicity and also demonstrate that manufactured metal oxide NPs in aquatic environment may affect the health condition of the aquatic organisms.

Analysis methods and reference concentrations of 12 minor and trace elements in fish blood plasma

A comprehensive review of the analytical literature revealed substantial under-representation of trace element concentrations in fish blood, particularly for marine species. We describe a simple dilution procedure to measure Li, Mg, K, Ca, Mn, Cu, Zn, Se, Rb, Sr, Ba and Pb concentrations in low volumes of blood plasma of adult plaice (Pleuronectes platessa) using high resolution-inductively coupled plasma-mass spectrometry (HR-ICP-MS). Captive male and female plaice (n = 18) were serially sampled for one year and samples collected outside of the spawning season (n = 157) used to estimate reference ranges for this species. Method accuracy was deemed satisfactory, based on its application to the analysis of a certified reference material. Precision was generally <3%, with the most conservative measure of precision being ≤10% for all elements except Pb (∼20%). This is the first study to analyse fish blood plasma by ICP-MS and includes some of the first reference ranges for trace element concentrations in fish blood.

Haematotoxicity of integrated textile mill effluent to an air-breathing fish Heteropneustes fossilis (Bloch)

The effect of integrated textile mill effluent on the haematological characteristic of the fish Heteropneustes fossilis was studied. LC50 values were found to be 34%-38% on 96-24 h duration. Four sub-lethal concentrations were selected for this study. Exposure to effluent caused an increase in large lymphocytes, monocytes, neutrophils and basiphil granulocytes and decrease in small lymphocytes in H.fossilis.

Immunotoxicology of non-functionalized engineered nanoparticles in aquatic organisms with special emphasis on fish--review of current knowledge, gap identification, and call for further research

The rapid increase in use of nanotechnology products is increasing the presence of metal, metal-oxide and carbon-based nanoparticles in the aquatic environment. These non-functionalized engineered nanoparticles can interact with the immune system of fish and invertebrates, and tip the ecological balance of population sustainability. Most nanoparticle types present in the aquatic environment, such as titanium dioxide, do not exhibit or have very low direct toxicity, but instead display silent or concealed sub-lethal effects on the immune system with serious implications. There is a gap in current available information regarding the immunotoxic potential of engineered nanoparticles toward aquatic organisms. Therefore, there is a critical need to provide the first comprehensive review of the effects of engineered non-functionalized nanoparticles on the immune system of aquatic animals, address the major gaps in current existing information, and recommend the future focus of research. This manuscript identifies cell mediated immunity and the phagocytic cells as the primary target of nanoparticle immunotoxicity. The immunotoxicity is primarily govern by lysosomal destabilization, frustrated phagocytosis, and change in function of the phagocytic cells, which decrease the ability of animals to defend themselves against pathogens and infectious diseases. Humoral immune system is a lesser target of direct immunotoxicity, but plays a critical role in dissemination of the nanoparticles through the body and their presentation to the phagocytic cells. The external innate immunity and the acquired immunity have not been connected with overly important and direct immunotoxic effects, but instead a big gap in current targeted research has been acknowledged.

Alteration in hematology of Labeo rohita under stress of pollution from Lakes of Bangalore, Karnataka, India

Blood is an indicator of physiological condition of an animal. Therefore, a field study was conducted to investigate the hematological parameters of wild population of rohu, Labeo rohita (Ham). The following aspects were evaluated in blood: hemoglobin content, red blood cell (RBC) and white blood cell (WBC) count, packed cell volume (PCV), and mean corpuscular volume (MCV) and mean corpuscular hemoglobin concentration (MCHC) values, and in plasma: cholesterol, protein, and glucose levels. For this purpose, rohu fish of varying sizes and weights were sampled from Hebbal (receiving a storm water drain) and Chowkalli lake (received domestic sewage and industrial effluents from various sources and was more polluted than Hebbal lake). It revealed noticeable differences in hemoglobin content, RBC and WBC count, and PCV and MCHC values. Severe anemia can be marked by a significant decrease in RBC count (p < 0.5), hemoglobin content, and PCV and MCHC values, whereas an increase in leukocyte count and MCV values were observed in fish from Chowkalli lake. Fish from lake B had fewer RBC and low concentration of serum protein and cholesterol. Serum concentration of glucose showed initial higher levels and then low concentration (900-1,500 g) in fish from lake B when compared to lake A. The variation in values of different parameters can be attributed to exposure of fish to various types of pollutants present mainly in the Chowkalli lake which receives heavy metals, synthetic detergents, petroleum products, and other acid and alkali substances from the nearby local industries. Other observations of these fish include dark body color and aggressive nature of fish.

Are the immunocompetence and the presence of metazoan parasites in cyprinid fish affected by reproductive efforts of cyprinid fish?

Each organism has the limited resources of energy that is distributed among important life traits. A trade-off between immune response and other physiological demands of organism especially costly reproduction is expected. Leuciscus cephalus, the cyprinid fish, was investigated during three periods varying in reproductive investment, that is, before-breeding, breeding, and after-breeding periods. We tested whether a potentially limited investment in immunity during the breeding is associated with higher susceptibility to the metazoan parasites. Following the immunocompetence handicap and sperm protection hypotheses, males expressing more elaborated sexual ornamentation should produce better quality sperm and be more parasitized. We found that reproductive investments in fish play an important role for energy allocation into somatic condition, immunity, and reproduction. The immune parameters including respiratory burst and leukocyte count were higher in breeding; however, parasite species richness and abundance appeared low. Males investing more in spawning tubercles reached high spermatocrite and were more parasitized by digeneans.

Micronucleus incidence and hematological effects in bullfrog tadpoles (Rana catesbeiana) exposed to 2-acetylaminofluorene and 2-aminofluorene

The micronucleus technique used with Rana catesbeiana tadpoles is useful for the evaluation of aromatic amine toxicity. When exposed to increasing concentrations of the aromatic amine 2-acetylaminofluorene (2-AAF 1 x 10(-8) M to 5 x 10(-5) M), R. catesbeiana tadpoles responded with an increasing frequency of micronuclei (MN) in the peripheral blood. Micronuclei increased fourfold with the 5 x 10(-5) M 2-AAF exposure. Micronuclei frequency significantly increased with concentrations as low as 5 x 10(-8) M. The time from initial mutagen exposure to the time of maximum number of MN present in the peripheral blood occurred at two separate times: 2 d and 14 d after exposure. The occurrence of two MN frequency peaks may be due to the presence of two erythrocyte populations from two hemopoietic sources (liver and kidneys) in young tadpoles. The occurrence of immature erythrocytes, as well as general degenerative changes [such as fragmentation (schistocytosis)] in the erythrocytes and vacuolated cytoplasms suggested 2-AAF may contribute to hemolytic anemia effects. 2-AAF also increased the frequency of rubricytes found in the peripheral blood, but had no significant effect on the hematocrit values of animals exposed to concentrations up to 1 x 10(-5) M. The tadpoles may have been producing rubricytes to replace the damaged red blood cells (RBCs). The direct-acting mutagen 2-aminofluorene (2-AF) was considerably more toxic to peripheral RBCs than the indirect-acting 2-AAF.(ABSTRACT TRUNCATED AT 250 WORDS)

Is monitoring of respiratory properties of the haemoglobin of the Lugworm Arenicola marina meaningfull?

Haemoglobin in Arenicola has a high oxygen affinity, with a half saturation oxygen pressure of about 180 Pa at pH 7.4 and 15°C. The oxygen affinity decreases with increasing copper concentration in the blood to about 300 Pa at pH 7.4, 15°C. at a copper concentration of 35 μg ml(-1). Copper exerts only a slight influence on the subunit cooperativity in oxygen binding. The oxygen affinity, subunit cooperativity and the Bohr effect are pH dependent. Copper affects the functioning of the blood by inhibiting oxygen binding to the haemoglobin in the respiratory area and oxygen delivery in the tissues.

Physiological effects of an additional stressor on fish exposed to a simulated heavy-metal-containing effluent from a sulfide ore smeltery

Perches (Perca fluviatilis), kept in slightly hypotonic brackish water, were exposed to dilutions of a simulated heavy-metal-containing effluent from a sulfide ore smeltery . Biochemical and hematological effects of the effluent, as well as the metal residues in liver and muscle tissues, were investigated after 12 and 27 days of exposure. The metal analyses revealed no significant uptake of metals in liver and muscle during the experiment. In spite of this, the exposed fish showed several physiological effects. Some of these, e.g., anemia, hypocalcemia, increased muscle water content, and reduced liver size, were of a transient nature, while others, such as disturbed chloride balance and hyperglycemia, seemed to be more persistent. At the end of the experiment (29-33 days of exposure), the physiological response to stress treatment (asphyxia) and a subsequent recovery were studied in exposed and unexposed fish. This stress investigation indicates that an additional stressor may strengthen the toxic effects of the heavy-metal-containing effluent. Furthermore, the secondary stress responses were more pronounced and the ability to recover from them seemed to be impaired in exposed fish as compared to unexposed fish.

Nickel toxicity on carbohydrate metabolism of a freshwater fish, Colisa fasciatus

Effects of sublethal concentration (0.8 of LC50 96 h) of nickel sulphate (NiSO4 X 7H2O) on muscle glycogen and blood lactic acid levels of a freshwater teleost, Colisa fasciatus, at time intervals from 3-96 h have been recorded. Muscle glycogen levels showed a general decrease at all time intervals compared with controls, with a maximum decrease of 35.2% at 96 h (P less than 0.001). Blood lactic acid showed an increase at all stages attaining a maximum of 78.12% at 12 h (P less than 0.001) except at 24 h where, for reasons not clearly understood, a distinct fall was recorded. The muscle glycogenolysis accompanied by blood hyperlacticaemia is probably the result of some direct action of nickel on the fish. The severe stress conditions caused by nickel-induced pathological changes in the gills and blood may also be responsible for these metabolic changes.

Cadmium toxicity: inducement of changes in blood and tissue metabolites in fish

The effects of acute (24 h) and chronic (90 days) cadmium (Cd) poisoning on blood and tissue metabolite levels of a teleost, Puntius conchonius were studied. Significant hyperglycemia with an increment in liver, kidney and ovary cholesterol occurred during acute Cd poisoning. By contrast, an enduring hypoglycemia and diminished levels of tissue cholesterol manifested the chronically intoxicated fish. Both acute and chronic Cd poisoning, however, caused marked hypocholesterolemia, glycogenolysis in liver and brain, and a concomitant rise in myocardium glycogen concentration. Testes cholesterol was found to be depleted after both acute and chronic (60 days) Cd poisoning.