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Venkateswara J Rao - One of the best experts on this subject based on the ideXlab platform.
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sub lethal effects of profenofos on tissue specific antioxidative responses in a euryhyaline fish Oreochromis mossambicus
Ecotoxicology and Environmental Safety, 2009Co-Authors: P Kavitha, Venkateswara J RaoAbstract:Abstract The euryhaline fish, Oreochromis mossambicus was exposed to sub-lethal concentration (30 μg/L) of profenofos (PF) for 28 days and allowed to recover for 7 days. Responses were evaluated through antioxidant enzyme activities in various tissues of fish. Glutathione-S-transferase (GST) and superoxide dismutase (SOD) activities showed transient increases in gill, viscera and muscle, but decreased in brain. However, catalase (CAT) and glutathione reductase (GR) were inhibited in gill and viscera. Reduced glutathione (GSH) levels were depleted in all the tissues and a significant induction in lipid peroxidation (LPO) was observed. Significant recovery in all the studied parameters was noticed at the end of recuperation period. The enhanced LPO in the present study suggests that reactive oxygen species (ROS)-induced oxidative damage could be one of the main toxic effect of PF. The increased LPO and alterations in the antioxidant defense system can be used as biomarkers in the pesticide-contaminated aquatic streams.
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biochemical alterations in euryhaline fish Oreochromis mossambicus exposed to sub lethal concentrations of an organophosphorus insecticide monocrotophos
Chemosphere, 2006Co-Authors: Venkateswara J RaoAbstract:The euryhaline fish, Oreochromis mossambicus was exposed to sub-lethal concentration (1.15 mg l(-1)) of a organophosphorus insecticide, monocrotophos (MCP) for 30 days and allowed to recover for seven days. Alanine aminotransferase (ALAT), aspartate aminotransferase (AAT), acid phosphatase (AcP), alkaline phosphatase (ALP), glycogen, lactate dehydrogenase (LDH), Reduced glutathione (GSH), gluthathione-S-transferase (GST) and acetylcholinesterase (AChE), were assayed in plasma and different tissues at regular intervals of day -3, -7, -15, -30 and after recovery period of seven days. The ALAT and AAT activities were increased in plasma and kidney, where as liver and gill showed decrease. Increase in AcP and ALP activities were observed in plasma, gill and kidney, and reduction of 42% and 50% was observed in liver. Glycogen was depleted in plasma, liver and gill indicates of typical stress related response of the fish with pesticide. LDH activity was decreased in liver and muscle, indicating tissue damage and muscular harm, but a significant increase in LDH activity in gill and brain was observed. Depletion in GSH activity was observed in all the tissues, there by enhancing the lipid peroxidation resulting in cell damage. The induction in hepatic GST levels indicates the protection against the toxicity of xenobiotic-induced lipid peroxidation. There was a significant recovery in all the above biochemical parameters studied in plasma and different tissues, after seven days recovery period. These results revealed that MCP affects the intermediary metabolism of O. mossambicus and that the assayed enzymes can work as good biomarkers of organophosphorus contamination.
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sublethal effects of an organophosphorus insecticide rpr ii on biochemical parameters of tilapia Oreochromis mossambicus
Comparative Biochemistry and Physiology C-toxicology & Pharmacology, 2006Co-Authors: Venkateswara J RaoAbstract:Abstract The effect of exposure to sublethal concentrations (0.017 mg L − 1 , 1/10 of LC 50 ) of the novel organophosphate (OP) insecticide, 2-butenoic acid-3-(diethoxyphosphinothioyl) methyl ester (RPR-II) on biochemical parameters in Oreochromis mossambicus was studied during exposure for 3, 7, 15, 30 and its recovery response after seven days. Acetylcholinesterase (AChE) activity of brain, gill and muscle was inhibited by 67%, 77% and 73% respectively on day-30. The plasma and kidney alanine aminotransferase (AlaAT), and aspartate aminotransferase (AspAT) activity increased, while decreases were observed in gill and liver. Increases in acid phosphatase (AcP), and alkaline phosphatase (AP) activities were observed in plasma, gill, and kidney, and reductions of 20% and 61% in liver AcP and AP, respectively. Depletion of glycogen was observed in all tissues, an indication of typical stress related response of the fish with pesticide. Lactate dehydrogenase (LDH) activity decreased in liver and muscle, indicating tissue damage but a significant increase in LDH activity in gill and brain was observed. Depletion of glutathione (GSH) was observed in all tissues, thereby enhancing lipid peroxidation resulting in cell damage. The induction in hepatic glutathione- S -transferase (GST) levels indicates protection against the toxicity of xenobiotic-induced lipid peroxidation. There was a significant recovery in the above biochemical parameters, in all tissues of fish after a recovery period of seven days. These results revealed that the OP insecticide RPR-II is highly toxic and affects the intermediary metabolism of O. mossambicus .
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effects of monocrotophos and its analogs in acetylcholinesterase activity s inhibition and its pattern of recovery on euryhaline fish Oreochromis mossambicus
Ecotoxicology and Environmental Safety, 2004Co-Authors: Venkateswara J RaoAbstract:Acute toxicity of monocrotophos (MCP) and its newly synthesized thiol analogs 2-butenoic acid-3-(diethoxyphosphinothionyl) methyl ester (RPR II) and 2-butenoic acid-3-(diethoxyphosphinothionyl) ethyl ester (RPR-V) was studied on euryhaline fish, Oreochromis mossambicus. The median lethal concentrations of MCP, RPR-II, and RPR-V are 11.506, 0.167, and 0.174 mgL(-1), respectively. Both the analogs were found to be 65-fold more toxic than MCP. Inhibitory and recovery patterns of brain, gill, and muscle acetylcholinesterase (AChE) was studied in vivo after exposure to LC(50) (96 h) concentrations. Recovery study was performed of regular intervals of day-1, -7, -14, -21, and -28 to establish the time course of 50% and 100% recovery in neurotransmitter enzyme of brain, gill, and muscle tissues. The sensitivity of the tissue AChE was in the order gill>brain>muscle. The relative toxicity of these compounds with regard to AChE was RPR-II>RPR-V>MCP. The MCP-treated fishes recovered at a faster rate than for RPR-V, followed by RPR-II.
Dinakaran R Michael - One of the best experts on this subject based on the ideXlab platform.
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water soluble fraction of tinospora cordifolia leaves enhanced the non specific immune mechanisms and disease resistance in Oreochromis mossambicus
Fish & Shellfish Immunology, 2010Co-Authors: Catherine P Alexander, John Wesly C Kirubakaran, Dinakaran R MichaelAbstract:The present paper describes the effect of water-soluble fraction of the leaves of the Indian medicinal plant, Tinospora cordifolia (Miers) on the non-specific immunity and disease resistance in Oreochromis mossambicus (Peters). Fish were intraperitoneally injected with 0, 6, 60 or 600 mg kg(-1) body weight, of the water soluble fraction. The non-specific humoral (lysozyme, antiprotease and complement) and cellular (production of reactive oxygen and nitrogen species and myeloperoxidase) responses and disease resistance against Aeromonas hydrophila were tested. All the doses of water-soluble fraction tested, significantly enhanced the serum lysozyme, antiprotease and natural haemolytic complement activities on most of the days tested. Similarly, all the doses of water-soluble fraction used, enhanced the cellular myeloperoxidase activity on all the days tested. The enhancement in the ROS and RNI production by peripheral blood leucocytes was observed on almost all the days tested, in most of the treated groups. All the doses of water-soluble fraction when administered as a single or double dose gave protection in terms of reduced percent mortality which is reflected in the increased Relative Percent Survival (RPS) values. The results clearly indicate the immunostimulatory and disease resistance properties of T. cordifolia leaf fraction and so its potential to be used as an immunoprophylactic in finfish aquaculture.
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enhancement of non specific immune responses and disease resistance on oral administration of nyctanthes arbortristis seed extract in Oreochromis mossambicus peters
Aquaculture Research, 2010Co-Authors: John Wesly C Kirubakaran, Catherine P Alexander, Dinakaran R MichaelAbstract:The immunomodulatory effect of the seed extract of an Indian medicinal plant Nyctanthes arbortristis L. (NAT) on non-specific immune responses and disease resistance of tilapia, Oreochromis mossambicus was investigated. Chloroform extract was administered orally as a feed supplement at doses of 0.01%, 0.1% or 1% for 3 weeks. Non-specific immune parameters such as serum lysozyme and alternate complement haemolytic (ACH50) activities, and cellular reactive oxygen species (ROS), reactive nitrogen intermediate (RNI) and myeloperoxidase production and disease resistance against live virulent Aeromonas hydrophila were investigated after 1, 2 or 3 weeks of feeding with chloroform extract-supplemented diet. The results of this study indicated that feeding tilapia for 2 weeks with selected doses of chloroform extract of NAT seeds significantly enhanced serum lysozyme, alternate complement activities and cellular ROS, RNI and MPO production. It was evident from the disease resistance test that feed supplemented with NAT seed extract at 0.1% or 1% level significantly reduced the mortality of O. mossambicus and a 3-week feeding with 0.1% extract-supplemented diet appears to be the optimal regimen for maximal disease resistance. Thus, the study indicates the scope of using the NAT extract as an immunoprophylactic in finfish aquaculture.
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enhancement of nonspecific immunity and disease resistance in Oreochromis mossambicus by solanum trilobatum leaf fractions
Fish & Shellfish Immunology, 2007Co-Authors: M Divyagnaneswari, D Christybapita, Dinakaran R MichaelAbstract:The purpose of this study was to determine the effect of water and hexane soluble fractions of the Indian medicinal plant, Solanum trilobatum on the nonspecific immune mechanisms and disease resistance in Oreochromis mossambicus. Fish were intraperitoneally injected with different doses of 0, 4, 40 or 400 mg kg(-1) body weight of water or hexane soluble fraction. The nonspecific immune mechanisms were assessed in terms of serum lysozyme activity, reactive oxygen species production and reactive nitrogen species production by peripheral blood leucocytes. The functional immunity in terms of percentage mortality and Relative Percent Survival (RPS) was assessed by a challenge with live Aeromonas hydrophila. Almost all the doses of both water and hexane soluble fractions enhanced the serum lysozyme activity. All the doses of water soluble fraction significantly enhanced the ROS production on most of the days tested. In hexane soluble fraction treated groups, the enhancement in the ROS production was observed at least on 2 days. All the doses of water soluble fraction significantly enhanced the production of RNS only on one day. The RNS production was enhanced significantly only in the group treated with 40 mg kg(-1) of hexane fraction. The leaf fraction administration preceding the challenge with live A. hydrophila, decreased the percentage mortality in the experimental group with the consequent increase in RPS values. This preliminary study indicates that S. trilobatum could be used to promote the health status of fish in intensive finfish aquaculture.
Gordon E Grau - One of the best experts on this subject based on the ideXlab platform.
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identification and genomic sequence of a ghrelin receptor ghs r like receptor in the mozambique tilapia Oreochromis mossambicus
Zoological Science, 2009Co-Authors: Hiroyuki Kaiya, Larry G Riley, Tetsuya Hirano, Gordon E Grau, Whitney Janzen, Mikiya Miyazato, Kenji KangawaAbstract:The growth hormone secretagogue-receptor (GHS-R) is an endogenous receptor for the gut hormone ghrelin (GRLN). Two isoforms of GHS-R have been identified in several animals: functional GHS-R1a and a splice variant of unknown function, GHS-R1b. Here we report identification of a GHS-R-like receptor (GHSR-LR) in the Mozambique tilapia, Oreochromis mossambicus. The cDNA is 1584 bp in length and encodes a 384-amino acid GHS-R1a ortholog. The amino acid sequence of tilapia GHS-R1a is 54, 60, 80 and 89% identical to that of rat, chicken, pufferfish, and seabream GHS-R1a, respectively. Genomic PCR revealed that the tilapia GHS-R gene is composed of two exons separated by a single intron. In addition, a GHS-R1b ortholog, which is generated by alternative splicing of the GHS-R gene and contains part of the intron, was identified and predicted to be a 298-amino acid protein. Functional analyses of tilapia GHS-R1a were conducted using mammalian HEK 293 and CHO cells, but the expected increase in intracellular calciu...
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identification of tilapia ghrelin and its effects on growth hormone and prolactin release in the tilapia Oreochromis mossambicus
Comparative Biochemistry and Physiology B, 2003Co-Authors: Hiroyuki Kaiya, Larry G Riley, Tetsuya Hirano, Gordon E Grau, Masayasu Kojima, Hiroshi Hosoda, Kenji KangawaAbstract:We have identified ghrelin and cDNA encoding precursor protein from the stomach of a euryhaline tilapia, Oreochromis mossambicus. The sequence of 20-amino acid tilapia ghrelin is GSSFLSPSQKPQNKVKSSRI. The third serine residue was modified by n-decanoic acid. The carboxyl-terminal end of the peptide possessed an amide structure. RT-PCR analysis revealed high levels of gene expression in the stomach and low levels in the brain, kidney and gill. Tilapia ghrelin stimulated growth hormone (GH) and prolactin (PRL) release from the organ-cultured tilapia pituitary at a dose of 10 nM. Thus, a novel regulatory mechanism of GH secretion by gastric ghrelin seems to be conserved in the tilapia. Stimulation of PRL release by homologous ghrelin has been reported in human, bullfrog and eel, and suggests the presence of growth hormone secretagogue receptor not only on somatotrophs but also on PRL cells of the tilapia pituitary.
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rat ghrelin stimulates growth hormone and prolactin release in the tilapia Oreochromis mossambicus
Zoological Science, 2002Co-Authors: Larry G Riley, Tetsuya Hirano, Gordon E GrauAbstract:Abstract Recently, ghrelin (Ghr), a new peptide which specifically stimulates growth hormone (GH) release from the pituitary, was identified in the rat and human stomach. Ghrelin has been shown to stimulate GH release by acting through a growth hormone secretagogue (GHS) receptor in the rat. The present study describes the in vitro effect of rat Ghr on the release of GH and two forms of prolactin (PRL177 and PRL188) in the tilapia, Oreochromis mossambicus. Rat Ghr stimulated the release of GH in a dose-related manner after 8 and 24 hr of incubation. Rat Ghr also significantly stimulated the release of PRL177 and PRL188 in a dose-related manner after 24 hr. Rat Ghr had no effect on the pituitary content of GH or PRL188, but significantly increased PRL177 content. These results show for the first time that rat Ghr significantly stimulates GH and PRL release in teleosts, and suggest that Ghr and a GHS receptor are present in fish.
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physiological and respiratory responses of the mozambique tilapia Oreochromis mossambicus to salinity acclimation
Comparative Biochemistry and Physiology Part A: Physiology, 1997Co-Authors: John D Morgan, Gordon E Grau, Tatsuya Sakamoto, George K IwamaAbstract:Abstract We have examined several physiological variables related to salinity acclimation in the euryhaline tilapia, Oreochromis mossambicus. Tilapia reared in fresh water (FW) were transferred to FW, isosmotic salinity (ISO, 12‰) and 75% seawater (SW, 25‰). Oxygen consumption, plasma levels of cortisol, growth hormone (GH), prolactins (tPRL177 and tPRL188), glucose, ions (Na+, K+, Cl−), and gill Na+,K+-ATPase activities were measured for up to 4 days in each salinity treatment. Plasma Na+ and Cl− concentrations were elevated 1 day after transfer to SW, but returned to FW values on day 4. Plasma cortisol and glucose levels were higher in FW and ISO than in SW 1 day after transfer. Plasma GH levels of tilapia in SW increased above FW and ISO values after 4 days, whereas plasma PRL levels decreased in ISO and SW compared to FW at 4 days. These results are consistent with the possible osmoregulation roles of GH and PRL in SW and FW, respectively. Gill Na+,K+-ATPase activity of tilapia in SW increased more than 2-fold over the FW value after 4 days, but activity of this enzyme did not change in ISO. Oxygen consumption rates of tilapia in SW were significantly elevated 4 days after transfer compared to FW and ISO. The results of this study indicate that the physiological changes associated with SW acclimation in tilapia represents a significant short-term energetic cost, and may account for as much as 20% of total body metabolism after 4 days in SW.
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relationships among ration salinity 17α methyltestosterone and growth in the euryhaline tilapia Oreochromis mossambicus
Aquaculture, 1995Co-Authors: Benny Ron, George K Iwama, Steve K Shimoda, Gordon E GrauAbstract:Abstract The effects of long-term 17α-methyltestosterone (MT) treatment (10 mg MT kg −1 feed) and ration size on the growth of the euryhaline tilapia, Oreochromis mossambicus , in fresh water (FW) and seawater (SW) were examined. Tilapia were fed a limited daily ration, starting initially at 18% of body weight for yolk-sac fry and decreasing gradually to 4% at 126 days. Eight treatments were employed. Control and MT treatment groups were replicated in FW and SW using either fish fed the limited daily ration described above or fish fed twice that ration. On limited ration, control fish in SW grew to twice the size of their FW counterparts. Treatment with MT increased growth in both FW and in SW tilapia. Doubling the feeding ration produced a significant increase in growth in SW, but not in FW fish. The greatest growth was observed in SW, MT-treated fish on double ration which grew to >4.2 × the size of FW control fish on a limited ration. Routine metabolic rate was measured in tilapia reared from the yolk-sac fry stage in FW or SW. The rate of oxygen consumption in the SW tilapia was 72.4 ± 11.3 mg kg −1 h −1 (mean ± SE, n = 6) and 148.2 ± 9.2 mg kg −1 h −1 in FW fish ( n = 6). These data suggest that the reduction in routine metabolism in O. mossambicus in SW may account for the increase in growth of the SW animals over their FW counterparts.
George K Iwama - One of the best experts on this subject based on the ideXlab platform.
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physiological and respiratory responses of the mozambique tilapia Oreochromis mossambicus to salinity acclimation
Comparative Biochemistry and Physiology Part A: Physiology, 1997Co-Authors: John D Morgan, Gordon E Grau, Tatsuya Sakamoto, George K IwamaAbstract:Abstract We have examined several physiological variables related to salinity acclimation in the euryhaline tilapia, Oreochromis mossambicus. Tilapia reared in fresh water (FW) were transferred to FW, isosmotic salinity (ISO, 12‰) and 75% seawater (SW, 25‰). Oxygen consumption, plasma levels of cortisol, growth hormone (GH), prolactins (tPRL177 and tPRL188), glucose, ions (Na+, K+, Cl−), and gill Na+,K+-ATPase activities were measured for up to 4 days in each salinity treatment. Plasma Na+ and Cl− concentrations were elevated 1 day after transfer to SW, but returned to FW values on day 4. Plasma cortisol and glucose levels were higher in FW and ISO than in SW 1 day after transfer. Plasma GH levels of tilapia in SW increased above FW and ISO values after 4 days, whereas plasma PRL levels decreased in ISO and SW compared to FW at 4 days. These results are consistent with the possible osmoregulation roles of GH and PRL in SW and FW, respectively. Gill Na+,K+-ATPase activity of tilapia in SW increased more than 2-fold over the FW value after 4 days, but activity of this enzyme did not change in ISO. Oxygen consumption rates of tilapia in SW were significantly elevated 4 days after transfer compared to FW and ISO. The results of this study indicate that the physiological changes associated with SW acclimation in tilapia represents a significant short-term energetic cost, and may account for as much as 20% of total body metabolism after 4 days in SW.
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relationships among ration salinity 17α methyltestosterone and growth in the euryhaline tilapia Oreochromis mossambicus
Aquaculture, 1995Co-Authors: Benny Ron, George K Iwama, Steve K Shimoda, Gordon E GrauAbstract:Abstract The effects of long-term 17α-methyltestosterone (MT) treatment (10 mg MT kg −1 feed) and ration size on the growth of the euryhaline tilapia, Oreochromis mossambicus , in fresh water (FW) and seawater (SW) were examined. Tilapia were fed a limited daily ration, starting initially at 18% of body weight for yolk-sac fry and decreasing gradually to 4% at 126 days. Eight treatments were employed. Control and MT treatment groups were replicated in FW and SW using either fish fed the limited daily ration described above or fish fed twice that ration. On limited ration, control fish in SW grew to twice the size of their FW counterparts. Treatment with MT increased growth in both FW and in SW tilapia. Doubling the feeding ration produced a significant increase in growth in SW, but not in FW fish. The greatest growth was observed in SW, MT-treated fish on double ration which grew to >4.2 × the size of FW control fish on a limited ration. Routine metabolic rate was measured in tilapia reared from the yolk-sac fry stage in FW or SW. The rate of oxygen consumption in the SW tilapia was 72.4 ± 11.3 mg kg −1 h −1 (mean ± SE, n = 6) and 148.2 ± 9.2 mg kg −1 h −1 in FW fish ( n = 6). These data suggest that the reduction in routine metabolism in O. mossambicus in SW may account for the increase in growth of the SW animals over their FW counterparts.
R Ramamurthi - One of the best experts on this subject based on the ideXlab platform.
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impact of chronic phosalone toxicity on erythropoietic activity of fish Oreochromis mossambicus
Biochemistry international, 1991Co-Authors: S J Reddy, B V Reddy, R RamamurthiAbstract:Effect of multiple sublethal concentrations of Phosalone on whole animal and kidney oxygen consumption, haematological indices and serum enzymes of freshwater fish, Oreochromis mossambicus, were carried out over a 90 day exposure period. Significant changes were observed which have been indicating that the presence of hypoxic condition in the biosystem, gradual increase in the rate of synthesis of haemoglobin and disruption of liver function during the toxicity of phosalone.