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Degree of piRNA sharing and Piwi gene expression in the skeletal muscle of Piaractus mesopotamicus (pacu), Colossoma macropomum (tambaqui), and the hybrid tambacu. Comp Biochem Physiol A Mol Integr Physiol 2021; 264:111120. [PMID: 34822974 DOI: 10.1016/j.cbpa.2021.111120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2021] [Revised: 11/14/2021] [Accepted: 11/15/2021] [Indexed: 11/24/2022]
Abstract
PiRNAs are a class of small noncoding RNAs that, in their mature form, bind to Piwi proteins to repress transposable element activity. Besides their role in gametogenesis and genome integrity, recent evidence indicates their action in non-germinative tissues. We performed a global analysis of piRNA and Piwi gene expression in the skeletal muscle of juveniles pacu (Piaractus mesopotamicus), tambaqui (Colossoma macropomum), and the hybrid tambacu to evaluate the degree of piRNA sharing among these three genotypes. Total RNA was sequenced and analyzed using specific parameters of piRNAs by bioinformatics tools. piRNA and Piwi gene expression was analyzed by RT-qPCR. We detected 24 piRNA clusters common to the three genotypes, with eight shared between pacu and tambacu, three between pacu and tambaqui, and five between tambaqui and tambacu; seven, five, and four clusters were unique to pacu, tambacu, and tambaqui, respectively. Genomic localization and fold change values showed two clusters and 100 piRNAs shared among the three genotypes. The gene expression of four piRNAs was evaluated to validate our bioinformatics results. piRNAs from cluster 17 were higher in tambacu than pacu and piRNAs from cluster 18 were more highly expressed in tambacu than tambaqui and pacu. In addition, the expression of Piwis 1 and 2 was higher in tambacu and tambaqui than pacu. Our results open an important window to investigate whether these small noncoding RNAs benefit the hybrid in terms of faster growth and offer a new perspective on the function of piRNAs and Piwis in fish skeletal muscle.
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Torson AS, Dong YW, Sinclair BJ. Help, there are ‘omics’ in my comparative physiology! J Exp Biol 2020; 223:223/24/jeb191262. [DOI: 10.1242/jeb.191262] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Abstract
‘Omics’ methods, such as transcriptomics, proteomics, lipidomics or metabolomics, yield simultaneous measurements of many related molecules in a sample. These approaches have opened new opportunities to generate and test hypotheses about the mechanisms underlying biochemical and physiological phenotypes. In this Commentary, we discuss general approaches and considerations for successfully integrating omics into comparative physiology. The choice of omics approach will be guided by the availability of existing resources and the time scale of the process being studied. We discuss the use of whole-organism extracts (common in omics experiments on small invertebrates) because such an approach may mask underlying physiological mechanisms, and we consider the advantages and disadvantages of pooling samples within biological replicates. These methods can bring analytical challenges, so we describe the most easily analyzed omics experimental designs. We address the propensity of omics studies to digress into ‘fishing expeditions’ and show how omics can be used within the hypothetico-deductive framework. With this Commentary, we hope to provide a roadmap that will help newcomers approach omics in comparative physiology while avoiding some of the potential pitfalls, which include ambiguous experiments, long lists of candidate molecules and vague conclusions.
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Affiliation(s)
- Alex S. Torson
- Department of Biology, The University of Western Ontario, London, ON N6A 5B7, Canada
| | - Yun-wei Dong
- The Key Laboratory of Mariculture, Ministry of Education, Fisheries College, Ocean University of China, Qingdao 266003, PR China
| | - Brent J. Sinclair
- Department of Biology, The University of Western Ontario, London, ON N6A 5B7, Canada
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Skeletal Muscle and the Effects of Ammonia Toxicity in Fish, Mammalian, and Avian Species: A Comparative Review Based on Molecular Research. Int J Mol Sci 2020; 21:ijms21134641. [PMID: 32629824 PMCID: PMC7370143 DOI: 10.3390/ijms21134641] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Revised: 06/26/2020] [Accepted: 06/29/2020] [Indexed: 12/22/2022] Open
Abstract
Typically, mammalian and avian models have been used to examine the effects of ammonia on skeletal muscle. Hyperammonemia causes sarcopenia or muscle wasting, in mammals and has been linked to sarcopenia in liver disease patients. Avian models of skeletal muscle have responded positively to hyperammonemia, differing from the mammalian response. Fish skeletal muscle has not been examined as extensively as mammalian and avian muscle. Fish skeletal muscle shares similarities with avian and mammalian muscle but has notable differences in growth, fiber distribution, and response to the environment. The wide array of body sizes and locomotion needs of fish also leads to greater diversity in muscle fiber distribution and growth between different fish species. The response of fish muscle to high levels of ammonia is important for aquaculture and quality food production but has not been extensively studied to date. Understanding the differences between fish, mammalian and avian species’ myogenic response to hyperammonemia could lead to new therapies for muscle wasting due to a greater understanding of the mechanisms behind skeletal muscle regulation and how ammonia effects these mechanisms. This paper provides an overview of fish skeletal muscle and ammonia excretion and toxicity in fish, as well as a comparison to avian and mammalian species.
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Li Y, Zhang J. The Effect of Acute Erythromycin Exposure on the Swimming Ability of Zebrafish ( Danio rerio) and Medaka ( Oryzias latipes). INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2020; 17:ijerph17103389. [PMID: 32414023 PMCID: PMC7277679 DOI: 10.3390/ijerph17103389] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/07/2020] [Revised: 04/15/2020] [Accepted: 04/17/2020] [Indexed: 11/20/2022]
Abstract
Erythromycin is a widely used antibiotic, and erythromycin contamination may pose a threat to aquatic organisms. However, little is known about the adverse effects of erythromycin on swimming ability. To quantify erythromycin-induced damage to fish swimming ability, Oryzias latipes and Danio rerio were acutely exposed to erythromycin. The swimming ability of the experimental fish was measured after exposure to varying doses of erythromycin (2 µg/L, 20 µg/L, 200 µg/L, and 2 mg/L) for 96 h. Burst speed (Uburst) and critical swimming speed (Ucrit) of experimental fish significantly decreased. In addition, gene expression analysis of O. latipes and D. rerio under erythromycin treatment (2 mg/L) showed that the expression of genes related to energy metabolism in the muscle was significantly reduced in both species of fish. However, the gene expression pattern in the head of the two species was differentially impacted; D. rerio showed endocrine disruption, while phototransduction was impacted in O. latipes. The results of our study may be used as a reference to control erythromycin pollution in natural rivers.
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The adenylate energy charge as a new and useful indicator of capture stress in chondrichthyans. J Comp Physiol B 2015; 186:193-204. [PMID: 26660290 DOI: 10.1007/s00360-015-0948-y] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2015] [Revised: 11/20/2015] [Accepted: 11/23/2015] [Indexed: 02/04/2023]
Abstract
Quantifying the physiological stress response of chondrichthyans to capture has assisted the development of fishing practices conducive to their survival. However, currently used indicators of stress show significant interspecific and intraspecific variation in species' physiological responses and tolerances to capture. To improve our understanding of chondrichthyan stress physiology and potentially reduce variation when quantifying the stress response, we investigated the use of the adenylate energy charge (AEC); a measure of available metabolic energy. To determine tissues sensitive to metabolic stress, we extracted samples of the brain, heart, liver, white muscle and blood from gummy sharks (Mustelus antarcticus) immediately following gillnet capture and after 3 h recovery under laboratory conditions. Capture caused significant declines in liver, white muscle and blood AEC, whereas no decline was detected in the heart and brain AEC. Following 3 h of recovery from capture, the AEC of the liver and blood returned to "unstressed" levels (control values) whereas white muscle AEC was not significantly different to that immediately after capture. Our results show that the liver is most sensitive to metabolic stress and white muscle offers a practical method to sample animals non-lethally for determination of the AEC. The AEC is a highly informative indicator of stress and unlike current indicators, it can directly measure the change in available energy and thus the metabolic stress experienced by a given tissue. Cellular metabolism is highly conserved across organisms and, therefore, we think the AEC can also provide a standardised form of measuring capture stress in many chondrichthyan species.
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Nachtigall PG, Dias MC, Carvalho RF, Martins C, Pinhal D. MicroRNA-499 expression distinctively correlates to target genes sox6 and rod1 profiles to resolve the skeletal muscle phenotype in Nile tilapia. PLoS One 2015; 10:e0119804. [PMID: 25793727 PMCID: PMC4368118 DOI: 10.1371/journal.pone.0119804] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2014] [Accepted: 02/02/2015] [Indexed: 11/22/2022] Open
Abstract
A class of small non-coding RNAs, the microRNAs (miRNAs), has been shown to be essential for the regulation of specific cell pathways, including skeletal muscle development, maintenance and homeostasis in vertebrates. However, the relative contribution of miRNAs for determining the red and white muscle cell phenotypes is far from being fully comprehended. To better characterize the role of miRNA in skeletal muscle cell biology, we investigated muscle-specific miRNA (myomiR) signatures in Nile tilapia fish. Quantitative (RT-qPCR) and spatial (FISH) expression analyses revealed a highly differential expression (forty-four-fold) of miR-499 in red skeletal muscle compared to white skeletal muscle, whereas the remaining known myomiRs were equally expressed in both muscle cell types. Detailed examination of the miR-499 targets through bioinformatics led us to the sox6 and rod1 genes, which had low expression in red muscle cells according to RT-qPCR, FISH, and protein immunofluorescence profiling experiments. Interestingly, we verified that the high expression of miR-499 perfectly correlates with a low expression of sox6 and rod1 target genes, as verified by a distinctive predominance of mRNA destabilization and protein translational decay to these genes, respectively. Through a genome-wide comparative analysis of SOX6 and ROD1 protein domains and through an in silico gene regulatory network, we also demonstrate that both proteins are essentially similar in vertebrate genomes, suggesting their gene regulatory network may also be widely conserved. Overall, our data shed light on the potential regulation of targets by miR-499 associated with the slow-twitch muscle fiber type phenotype. Additionally the results provide novel insights into the evolutionary dynamics of miRNA and target genes enrolled in a putative constrained molecular pathway in the skeletal muscle cells of vertebrates.
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Affiliation(s)
- Pedro G. Nachtigall
- Department of Genetics, Institute of Biosciences, Sao Paulo State University (UNESP), Botucatu, Sao Paulo, 18618-970, Brazil
| | - Marcos C. Dias
- Department of Morphology, Institute of Biosciences, Sao Paulo State University (UNESP), Botucatu, Sao Paulo, 18618-970, Brazil
- Health Sciences Institute, Federal University of Mato Grosso (UFMT), Sinop, Mato Grosso, 78550-000, Brazil
| | - Robson F. Carvalho
- Department of Morphology, Institute of Biosciences, Sao Paulo State University (UNESP), Botucatu, Sao Paulo, 18618-970, Brazil
| | - Cesar Martins
- Department of Morphology, Institute of Biosciences, Sao Paulo State University (UNESP), Botucatu, Sao Paulo, 18618-970, Brazil
| | - Danillo Pinhal
- Department of Genetics, Institute of Biosciences, Sao Paulo State University (UNESP), Botucatu, Sao Paulo, 18618-970, Brazil
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Rearing temperature induces changes in muscle growth and gene expression in juvenile pacu (Piaractus mesopotamicus). Comp Biochem Physiol B Biochem Mol Biol 2013; 169:31-7. [PMID: 24365169 DOI: 10.1016/j.cbpb.2013.12.004] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2013] [Revised: 12/12/2013] [Accepted: 12/14/2013] [Indexed: 01/27/2023]
Abstract
Pacu (Piaractus mesopotamicus) is a fast-growing fish that is extensively used in Brazilian aquaculture programs and shows a wide range of thermal tolerance. Because temperature is an environmental factor that influences the growth rate of fish and is directly related to muscle plasticity and growth, we hypothesized that different rearing temperatures in juvenile pacu, which exhibits intense muscle growth by hyperplasia, can potentially alter the muscle growth patterns of this species. The aim of this study was to analyze the muscle growth characteristics together with the expression of the myogenic regulatory factors MyoD and myogenin and the growth factor myostatin in juvenile pacu that were submitted to different rearing temperatures. Juvenile fish (1.5 g weight) were distributed in tanks containing water and maintained at 24°C (G24), 28 °C (G28) and 32 °C (G32) (three replicates for each group) for 60 days. At days 30 and 60, the fish were anesthetized and euthanized, and muscle samples (n=12) were collected for morphological, morphometric and gene expression analyses. At day 30, the body weight and standard length were lower for G24 than for G28 and G32. Muscle fiber frequency in the <25 μm class was significantly higher in G24, and the >50 μm class was lower in G24. MyoD gene expression was higher in G24 compared with that in G28 and G32, and myogenin and myostatin mRNA levels were higher in G24 than G28. At day 60, the body weight and the standard length were higher in G32 but lower in G24. The frequency distribution of the <25 μm diameter muscle fibers was higher in G24, and that of the >50 μm class was lower in G24. MyoD mRNA levels were higher in G24 and G32, and myogenin mRNA levels were similar between G24 and G28 and between G24 and G32 but were higher in G28 compared to G32. The myostatin mRNA levels were similar between the studied temperatures. In light of our results, we conclude that low rearing temperature altered the expression of muscle growth-related genes and induced a delay in muscle growth in juvenile pacu (P. mesopotamicus). Our study provides a clear example of thermally induced phenotypic plasticity in pacu fish and shows that changing the rearing temperature during the juvenile stage can have a considerable effect on gene expression and muscle growth in this species.
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Sinha AK, Liew HJ, Diricx M, Blust R, De Boeck G. The interactive effects of ammonia exposure, nutritional status and exercise on metabolic and physiological responses in gold fish (Carassius auratus L.). AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2012; 109:33-46. [PMID: 22204987 DOI: 10.1016/j.aquatox.2011.11.002] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/17/2011] [Revised: 11/04/2011] [Accepted: 11/08/2011] [Indexed: 05/31/2023]
Abstract
This study aimed to elucidate the physiological effects of high environmental ammonia (HEA) following periods of feeding (2% body weight) and starvation (unfed for 7 days prior to sampling) in gold fish (Carassius auratus). Both groups of fish were exposed to HEA (1 mg/L; Flemish water quality guideline) for 0 h (control), 3 h, 12 h, 1 day, 4 days, 10 days, 21 days and 28 days. Measurements of weight gain (%), oxygen consumption (MO2), ammonia excretion rate, ammonia quotient (AQ), critical swimming speeds (Ucrit), plasma and muscle ammonia accumulation, plasma lactate, liver and muscle glycogen, lipid and protein content were done at various time intervals during the experimental periods. Overall, ammonia excretion rates, plasma ammonia accumulation and AQ were significantly affected by food regime in ammonia free water. HEA, the additional challenge in the present study, significantly altered all the studied parameters among fed and starved groups in days-dependent manner. Results show that weight gain (%), MO2, Ucrit, protein content in liver and muscle, and glycogen content in muscle among starved fish under HEA were considerably reduced compared to control and fed fish. Additionally a remarkable increase in plasma ammonia level, muscle ammonia, lactate accumulation and AQ was seen. However in fed fish, MO2, ammonia excretion rate, AQ and lactate level augmented after exposure to HEA. These results indicate that starved fish appeared more sensitive to HEA than fed fish. Furthermore, as expected, the toxic effect of ammonia exposure in both feeding treatments was exacerbated when imposed to exhaustive swimming (swum at 3/4th Ucrit). Such effects were more pronounced in starved fish. This suggests that starvation can instigate fish more vulnerable to external ammonia during exercise. Therefore, it was evident from our study that feeding ameliorates ammonia handling and reduces its toxicity during both routine and exhaustive swimming. Moreover, recovery was observed for some physiological parameters (e.g. MO2, ammonia excretion, Ucrit, plasma ammonia) during the last exposure periods (21-28 days) while for others (e.g. growth, tissue glycogen and protein content, muscle ammonia) effects only became apparent at this time. In the future, these results need to be considered in ecological context as fish in ammonia polluted may experience different phenomenon (starvation and exercise) simultaneously.
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Affiliation(s)
- Amit Kumar Sinha
- Laboratory for Ecophysiology, Biochemistry and Toxicology, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp, Belgium.
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de Almeida FLA, Pessotti NS, Pinhal D, Padovani CR, Leitão NDJ, Carvalho RF, Martins C, Portella MC, Dal Pai-Silva M. Quantitative expression of myogenic regulatory factors MyoD and myogenin in pacu (Piaractus mesopotamicus) skeletal muscle during growth. Micron 2010; 41:997-1004. [DOI: 10.1016/j.micron.2010.06.012] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2010] [Revised: 06/22/2010] [Accepted: 06/23/2010] [Indexed: 11/27/2022]
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Effects of exercise on L-carnitine and lipid metabolism in African catfish (Clarias gariepinus) fed different dietary L-carnitine and lipid levels. Br J Nutr 2009; 103:1139-50. [PMID: 19930769 DOI: 10.1017/s0007114509993035] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
African catfish (Clarias gariepinus) were fed four isonitrogenous diets (34 % crude protein), each containing one of two lipid (100 or 180 g/kg) and two L-carnitine (15 or 1000 mg/kg) levels. After 81 d of feeding, thirty-two fish (body weight 32 g) from each dietary group were randomly selected, sixteen fish were induced to a 3-h swim (speed of 1.5 body length (BL)/s), while the other sixteen fish were kept under resting condition. Fish fed 1000 mg L-carnitine accumulated 3.5 and 5 times more L-carnitine in plasma and muscle, respectively, than fish fed the 15 mg L-carnitine. Muscle L-carnitine content was significantly lower in exercised fish than in rested fish. High dietary lipid level (fish oil) led to an increase in muscle n-3 PUFA content and a decrease in SFA and MUFA content. In liver, the increase in dietary lipid level resulted in an increased levels of both n-6 and n-3 PUFA. L-carnitine supplementation significantly decreased n-3 PUFA content. Exercise decreased n-3 PUFA in both muscle and liver. Plasma lactate and lactate dehydrogenase, normally associated with increased glycolytic processes, were positively correlated with exercise and inversely correlated with dietary L-carnitine level. L-carnitine supplementation reduced significantly the RQ from 0.72 to 0.63, and an interaction between dietary L-carnitine and lipid was observed (P < 0.03). Our results indicate that an increase in fatty acids (FA) intake may promote FA oxidation, and both carnitine and exercise might influence the regulation of FA oxidation selectivity.
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Michelin AC, Justulin LA, Delella FK, Padovani CR, Felisbino SL, Dal-Pai-Silva M. Differential MMP-2 and MMP-9 activity and collagen distribution in skeletal muscle from pacu (Piaractus mesopotamicus) during juvenile and adult growth phases. Anat Rec (Hoboken) 2009; 292:387-95. [PMID: 19248158 DOI: 10.1002/ar.20863] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Here, we evaluated collagen distribution and matrix metalloproteinases (MMPs) MMP-2 and MMP-9 activities in skeletal muscle of pacu (Piaractus mesopotamicus) during juvenile and adult growth phases. Muscle samples from juvenile and adult fishes were processed by histochemistry for collagen system fibers and for gelatin-zymography for MMP-2 and MMP-9 activities analysis. Picrosirius staining revealed a myosept, endomysium, and perimysium-like structures in both growth phases and muscle types, with increased areas of collagen fibers in adults, mainly in red muscle. Reticulin staining showed that reticular fibers in the endomysium-like structure were thinner and discontinuous in the red muscle fibers. The zymography revealed clear bands of the pro- MMP-9, active- MMP-9, intermediate- MMP-2, and active- MMP-2 forms in red and white muscle in both growth phases. MMP-2 activity was more intense in juvenile than adult muscle fibers. Comparing the red and white muscle types, MMP-2 activity was significantly higher in red muscle in adult phase only. The activity of MMP-9 forms was similar in juvenile red and white muscles and in the adult red muscle, without any activity in adult white muscle. In conclusion, our results show that, in pacu, the higher activities of MMP-2 and -9 are associated with the rapid muscle growth in juvenile age and in adult fish, these activities are related with a different red and white muscle physiology. This study may contribute to the understanding muscle growth mechanisms and may also contribute to analyse red and the white muscle parameters of firmness and softness, respectively, of the commercial product.
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Affiliation(s)
- Aline Cristina Michelin
- Department of Morphology, Institute of Biosciences, São Paulo State University (UNESP), Botucatu, São Paulo, Brazil
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12
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Hildebrand JL, Bains OS, Lee DSH, Kennedy CJ. Functional and energetic characterization of P-gp-mediated doxorubicin transport in rainbow trout (Oncorhynchus mykiss) hepatocytes. Comp Biochem Physiol C Toxicol Pharmacol 2009; 149:65-72. [PMID: 18664392 DOI: 10.1016/j.cbpc.2008.07.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/01/2008] [Revised: 07/03/2008] [Accepted: 07/07/2008] [Indexed: 12/13/2022]
Abstract
An assessment of energetic costs associated with P-glycoprotein (P-gp)-mediated xenobiotic efflux is important in understanding the energy budgets, tradeoffs, and fitness of organisms inhabiting contaminated environments. Here, a functional characterization and determination of the energetic costs associated with doxorubicin (DOX) efflux was examined in isolated hepatocytes of rainbow trout. The accumulation and efflux of DOX were both concentration dependent. The efflux of DOX over a 3 h incubation period resulted in a significant decrease in intracellular ATP concentrations (maximum decrease 25%) compared to control baseline levels, while significant increases in concentrations of ADP (max. 26%), AMP (max. 36%) and inorganic phosphate (max. 11%). were observed. In addition, significant reductions in the adenylate energy charge ([AEC]: max 11%), and phosphorylation potential ([PP]: max. 53%) were shown in cells incubated with DOX compared to control cells. Inhibition of DOX efflux (max. 61%) by the non-competitive P-gp inhibitor tariquidar (XR9576), demonstrated that changes in ATP, ADP, AMP, inorganic phosphate concentrations, AEC and PP in DOX-exposed hepatocytes were mainly due to P-gp activity. Overall, these results indicate that the exposure of trout hepatocytes to DOX increases energetic and metabolic costs that are associated specifically with P-gp efflux activity.
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Hallman TM, Rojas-Vargas AC, Jones DR, Richards JG. Differential recovery from exercise and hypoxia exposure measured using 31P- and 1H-NMR in white muscle of the common carp Cyprinus carpio. ACTA ACUST UNITED AC 2008; 211:3237-48. [PMID: 18840657 DOI: 10.1242/jeb.019257] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Phosphocreatine (PCr) was reduced to equivalent levels in carp white muscle by high-intensity exhaustive exercise and exposure to hypoxia at 15 degrees C and 25 degrees C in order to assess the influence of intracellular pH (pH(i)), temperature and lactate levels on PCr recovery in vivo. High-intensity exercise resulted in a significantly lower pH(i) compared with hypoxia exposure and the rate of PCr depletion and tissue acidification during hypoxia exposure was significantly higher in carp held at 25 degrees C compared with those at 15 degrees C. During recovery, PCr and pH(i) returned towards normoxia/resting levels at a faster rate following hypoxia exposure than after exercise. The lower pH(i) in exercised carp caused a greater perturbation to cellular energy status (assessed as the free energy of ATP hydrolysis; DeltafG') and resulted in a higher [ATP]/[ADP(free)] ratio, which may limit mitochondrial ATP production and contribute to the slower recovery from exercise compared with recovery from hypoxia exposure. Rates of recovery from exercise and hypoxia exposure were not affected by acclimation temperature (15 and 25 degrees C), suggesting that the processes involved in acclimation compensate for the Q(10) effects of temperature on metabolic processes. Finally, using a dual 31P-NMR and 1H-NMR analysis technique, we demonstrated that the greater tissue acidification observed after high-intensity exercise compared with hypoxia exposure occurred at similar white muscle lactate concentrations.
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Affiliation(s)
- Troy M Hallman
- Department of Zoology, The University of British Columbia, Vancouver, BC, Canada
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Mandic M, Lau GY, Nijjar MMS, Richards JG. Metabolic recovery in goldfish: A comparison of recovery from severe hypoxia exposure and exhaustive exercise. Comp Biochem Physiol C Toxicol Pharmacol 2008; 148:332-8. [PMID: 18590983 DOI: 10.1016/j.cbpc.2008.04.012] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/09/2008] [Revised: 04/28/2008] [Accepted: 04/29/2008] [Indexed: 10/22/2022]
Abstract
Severe hypoxia exposure and exhaustive exercise in goldfish both elicit a strong activation of substrate-level phosphorylation with the majority of the metabolic perturbations occurring in the white muscle. Approximately half of the muscle glycogen breakdown observed during severe hypoxia exposure was accounted for by ethanol production and loss to the environment, which limited the extent of muscle glycogen recovery when animals were returned to normoxic conditions. Ethanol production in goldfish is not solely a response to anoxia/hypoxia exposure however, as a transient increase in ethanol production was observed during the early stages of recovery from exhaustive exercise. These data suggest that ethanol production is a ubiquitous "anaerobic" end product, which accumulates whenever metabolic demands exceed mitochondrial oxidative potential. Exhaustive exercise and hypoxia exposure both caused a 7 to 8 micromol g(-1) wet mass increase in muscle [lactate] and the rates of recovery following these perturbations were similar. The rates of muscle PCr and pHi recovery after hypoxia exposure and exhaustive exercise were similar with levels returning to controls values within 0.5 h. Surprisingly, liver [glycogen] was not depleted during exposure to severe hypoxia, however, during recovery from both hypoxia and exercise dramatically different responses in liver [glycogen] were noted. During the early stages of recovery, liver [glycogen] transiently increased to high levels after exhaustive exercise, while during recovery from hypoxia there was a transient decrease in liver glycogen over the same time frame. Overall, this points to the liver playing a dramatically different role in facilitating recovery from exercise compared with hypoxia exposure.
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Affiliation(s)
- Milica Mandic
- Department of Zoology, The University of British Columbia, Vancouver, British Columbia, V6T 1Z4 Canada
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de Almeida FLA, Carvalho RF, Pinhal D, Padovani CR, Martins C, Dal Pai-Silva M. Differential expression of myogenic regulatory factor MyoD in pacu skeletal muscle (Piaractus mesopotamicus Holmberg 1887: Serrasalminae, Characidae, Teleostei) during juvenile and adult growth phases. Micron 2008; 39:1306-11. [PMID: 18400505 DOI: 10.1016/j.micron.2008.02.011] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2007] [Revised: 02/19/2008] [Accepted: 02/20/2008] [Indexed: 11/27/2022]
Abstract
Skeletal muscle is the edible part of the fish. It grows by hypertrophy and hyperplasia, events regulated by differential expression of myogenic regulatory factors (MRFs). The study of muscle growth mechanisms in fish is very important in fish farming development. Pacu (Piaractus mesopotamicus) is one of the most important food species farmed in Brazil and has been extensively used in Brazilian aquaculture programs. The aim of this study was to analyze hyperplasia and hypertrophy and the MRF MyoD expression pattern in skeletal muscle of pacu (P. mesopotamicus) during juvenile and adult growth stages. Juvenile (n=5) and adult (n=5) fish were anaesthetized, sacrificed, and weight (g) and total length (cm) determined. White dorsal region muscle samples were collected and immersed in liquid nitrogen. Transverse sections (10 microm thick) were stained with Haematoxilin-Eosin (HE) for morphological and morphometric analysis. Smallest fiber diameter from 100 muscle fibers per animal was calculated in each growth phase. These fibers were grouped into three classes (<20, 20-50, and >50 microm) to evaluate hypertrophy and hyperplasia in white skeletal muscle. MyoD gene expression was determined by semi-quantitative RT-PCR. PCR products were cloned and sequenced. Juvenile and adult pacu skeletal muscle had similar morphology. The large number of <20 microm diameter muscle fibers observed in juvenile fish confirms active hyperplasia. In adult fish, most fibers were over 50 microm diameter and denote more intense muscle fiber hypertrophy. The MyoD mRNA level in juveniles was higher than in adults. A consensus partial sequence for MyoD gene (338 base pairs) was obtained. The Pacu MyoD nucleotide sequence displayed high similarity among several vertebrates, including teleosts. The differential MyoD gene expression observed in pacu white muscle is possibly related to differences in growth patterns during the phases analyzed, with hyperplasia predominant in juveniles and hypertrophy in adult fish. These results should provide a foundation for understanding the molecular control of skeletal muscle growth in economically important Brazilian species, with a view to improving production quality.
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Suski CD, Kieffer JD, Killen SS, Tufts BL. Sub-lethal ammonia toxicity in largemouth bass. Comp Biochem Physiol A Mol Integr Physiol 2006; 146:381-9. [PMID: 17258484 DOI: 10.1016/j.cbpa.2006.11.005] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2006] [Revised: 11/16/2006] [Accepted: 11/17/2006] [Indexed: 11/23/2022]
Abstract
Guidelines for ammonia toxicity in fish are often determined using static exposure tests with immature fish over a 96-h period. These results may not be relevant to aquaculture, hauling or angling tournament scenarios where mature fish can be exposed to ammonia for shorter durations, often following additional stressors such as handling. The current study sought to quantify (1) the impact of ambient ammonia on the ability of largemouth bass to recover from exercise, (2) the behavioural response of largemouth bass to elevated ambient ammonia and (3) the concentration of ammonia that can accumulate in a live-release vessel at an angling tournament. After approximately 3 h, total ammonia (T(amm)) concentrations in a live-release vessel at an angling tournament were almost 200 muM. Exposure of fish to 1000 microM T(amm) (a value approximately 80% below the criteria maximum concentration for largemouth bass) caused significant reductions in ventilation rates, and increases in erratic swimming and irregular ventilation. Exposure to 100 microM T(amm) impaired the ability of largemouth bass to recover from exercise relative to fish recovering in fresh water. Therefore, sub-lethal ambient ammonia concentrations cause physiological disturbances that can impair the recovery of largemouth bass from exercise.
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Affiliation(s)
- C D Suski
- Department of Biology, Kingston, Queen's University, Canada ON K7L 3N6.
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Blanco SL, Suárez MP, San Juan F. Seasonal changes of nucleotides in mussel (Mytilus galloprovincialis) mantle tissue. Comp Biochem Physiol B Biochem Mol Biol 2006; 143:384-90. [PMID: 16455280 DOI: 10.1016/j.cbpb.2005.12.021] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2005] [Revised: 12/20/2005] [Accepted: 12/21/2005] [Indexed: 10/25/2022]
Abstract
Seasonal variations of nucleotides in Mytilus galloprovincialis mantle tissue were analyzed. Separation and quantification was achieved by reversed-phase high-performance liquid chromatography. Total nucleotides show a pronounced seasonal variation with maximum and minimum values in autumn and spring, respectively. Adenine nucleotides accounted for the major part in spring and summer, guanosine and cytidine nucleotides in winter; uridine nucleotides were relatively constant throughout the year. Their inverse variation suggests inter-conversion among them and the maintenance of the potential cell energy in winter by other triphosphate nucleotides different from ATP. These results reflect environmental and nutritional conditions, and also the reserves and gametogenic cycles taking place in M. galloprovincialis mantle tissue.
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Affiliation(s)
- S L Blanco
- Departamento de Bioquímica, Genética e Inmunología, Facultad de Ciencias del Mar, Universidad de Vigo, Lagoas-Marcosende s/n. 36200 Vigo, Spain
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Abstract
Peter Hochachka was one of the most creative forces in the field of comparative physiology during the past half-century. His career was truly an exploratory adventure, in both intellectual and geographic senses. His broad comparative studies of metabolism in organisms as diverse as trout, tunas, oysters, squid, turtles, locusts, hummingbirds, seals, and humans revealed the adaptable features of enzymes and metabolic pathways that provide the biochemical bases for diverse lifestyles and environments. In its combined breadth and depth, no other corpus of work better illustrates the principle of "unity in diversity" that marks comparative physiology. Through his publications, his stimulating mentorship, his broad editorial services, and his continuous-and highly infectious-enthusiasm for his field, Peter Hochachka served as one of the most influential leaders in the transformation of comparative physiology.
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Affiliation(s)
- George N Somero
- Department of Biological Sciences, Hopkins Marine Station, Stanford University, Pacific Grove, California 93950-3094, USA.
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Tay ASL, Chew SF, Ip YK. The swamp eel Monopterus albus reduces endogenous ammonia production and detoxifies ammonia to glutamine during 144 h of aerial exposure. J Exp Biol 2003; 206:2473-86. [PMID: 12796462 DOI: 10.1242/jeb.00464] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The swamp eel Monopterus albus inhabits muddy ponds, swamps, canals and rice fields, where it can burrow within the moist earth during the dry summer season, thus surviving for long periods without water. This study aimed to elucidate the strategies adopted by M. albus to defend against endogenous ammonia toxicity when kept out of water for 144 h (6 days). Like any other fish, M. albus has difficulties in excreting ammonia during aerial exposure. In fact, the rates of ammonia and urea excretions decreased significantly in specimens throughout the 144 h of aerial exposure. At 144 h, the ammonia and urea excretion rates decreased to 20% and 25%, respectively, of the corresponding control values. Consequently, ammonia accumulated to high levels in the tissues and plasma of the experimental specimens. Apparently, M. albus has developed relatively higher ammonia tolerance at the cellular and subcellular levels compared with many other teleost fish. Since the urea concentration in the tissues of specimens exposed to air remained low, urea synthesis was apparently not adopted as a strategy to detoxify endogenous ammonia during 144 h of aerial exposure. Instead, ammonia produced through amino acid catabolism was detoxified to glutamine, leading to the accumulation of glutamine in the body during the first 72 h of aerial exposure. Complementing the increased glutamine formation was a significant increase in glutamine synthetase activity in the liver of specimens exposed to air for 144 h. Formation of glutamine is energetically expensive. It is probably because M. albus remained relatively inactive on land that the reduction in energy demand for locomotory activity facilitated its exploitation of glutamine formation to detoxify endogenous ammonia. There was a slight decrease in the glutamine level in the body of the experimental animals between 72 h and 144 h of aerial exposure, which indicates that glutamine might not be the end product of nitrogen metabolism. In addition, these results suggest that suppression of endogenous ammonia production, possibly through reductions in proteolysis and amino acid catabolism, acts as the major strategy to avoid ammonia intoxication in specimens exposed to air for >/=72 h. It is concluded that glutamine formation and reduction in ammonia production together served as effective strategies to avoid the excessive accumulation of ammonia in the body of M. albus during 144 h of aerial exposure. However, these strategies might not be adequate to sustain the survival of M. albus in the mud for longer periods during drought because ammonia and glutamine concentrations had already built up to high levels in the body of specimens exposed to air for 144 h.
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Affiliation(s)
- Angeline S L Tay
- Department of Biological Science, National University of Singapore, Kent Ridge, Singapore 117543, Republic of Singapore
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21
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Wilkie MP. Ammonia excretion and urea handling by fish gills: present understanding and future research challenges. THE JOURNAL OF EXPERIMENTAL ZOOLOGY 2002; 293:284-301. [PMID: 12115902 DOI: 10.1002/jez.10123] [Citation(s) in RCA: 168] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
In fresh water fishes, ammonia is excreted across the branchial epithelium via passive NH(3) diffusion. This NH(3) is subsequently trapped as NH(4)(+) in an acidic unstirred boundary layer lying next to the gill, which maintains the blood-to-gill water NH(3) partial pressure gradient. Whole animal, in situ, ultrastructural and molecular approaches suggest that boundary layer acidification results from the hydration of CO(2) in the expired gill water, and to a lesser extent H(+) excretion mediated by apical H(+)-ATPases. Boundary layer acidification is insignificant in highly buffered sea water, where ammonia excretion proceeds via NH(3) diffusion, as well as passive NH(4)(+) diffusion due to the greater ionic permeability of marine fish gills. Although Na(+)/H(+) exchangers (NHE) have been isolated in marine fish gills, possible Na(+)/NH(4)(+) exchange via these proteins awaits evaluation using modern electrophysiological and molecular techniques. Although urea excretion (J(Urea)) was thought to be via passive diffusion, it is now clear that branchial urea handling requires specialized urea transporters. Four urea transporters have been cloned in fishes, including the shark kidney urea transporter (shUT), which is a facilitated urea transporter similar to the mammalian renal UT-A2 transporter. Another urea transporter, characterized but not yet cloned, is the basolateral, Na(+) dependent urea antiporter of the dogfish gill, which is essential for urea retention in ureosmotic elasmobranchs. In ureotelic teleosts such as the Lake Magadi tilapia and the gulf toadfish, the cloned mtUT and tUT are facilitated urea transporters involved in J(Urea). A basolateral urea transporter recently cloned from the gill of the Japanese eel (eUT) may actually be important for urea retention during salt water acclimation. A multi-faceted approach, incorporating whole animal, histological, biochemical, pharmacological, and molecular techniques is required to learn more about the location, mechanism of action, and functional significance of urea transporters in fishes.
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Affiliation(s)
- Michael Patrick Wilkie
- Division of Life Sciences, University of Toronto at Scarborough, Scarborough, Ontario, M1C 1A6 Canada.
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Beaulieu MA, Guderley H. Changes in qualitative composition of white muscle with nutritional status of Atlantic cod, Gadus morhua. Comp Biochem Physiol A Mol Integr Physiol 1998; 121:135-41. [PMID: 9883575 DOI: 10.1016/s1095-6433(98)10114-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Proteins from white muscle are mobilized to cover energy requirements during long-term starvation in fish. Using SDS-polyacrylamide gel electrophoresis, we compared the soluble and insoluble fractions of white muscle proteins from fed and starved Atlantic cod, Gadus morhua, to establish whether preferential preservation or degradation of specific proteins occurred during starvation. While starvation induced no qualitative changes in the electrophoretic pattern of the myofibrillar fraction, our results document differential decreases in the levels of soluble proteins during fasting. Moreover, immunoblot analysis using a monoclonal antibody directed against actin, showed a marked accumulation of this protein in the sarcoplasmic fraction of starved individuals, most likely due to myofibrillar degradation.
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Affiliation(s)
- M A Beaulieu
- Department de Biologie, Université Laval, Qubec, Canada
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25
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The effect of dietary lipids on tissue lipids and ammonia excretion in European eels (Anguilla anguilla). ACTA ACUST UNITED AC 1995. [DOI: 10.1016/0300-9629(95)00029-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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26
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HOLDWAY DA, BRENNAN SE, AHOKAS JT. Short review of selected fish biomarkers of xenobiotic exposure with an example using fish hepatic mixed-function oxidase. AUSTRAL ECOL 1995. [DOI: 10.1111/j.1442-9993.1995.tb00520.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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27
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Barton KN, Gerrits MF, Ballantyne JS. Effects of exercise on plasma nonesterified fatty acids and free amino acids in Arctic char (Salvelinus alpinus). ACTA ACUST UNITED AC 1995. [DOI: 10.1002/jez.1402710304] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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28
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Caldwell CA, Hinshaw JM. Nucleotides and the adenylate energy charge as indicators of stress in rainbow trout (Oncorhynchus mykiss) subjected to a range of dissolved oxygen concentrations. ACTA ACUST UNITED AC 1994. [DOI: 10.1016/0305-0491(94)90015-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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29
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Effects of nutrition (herbivore vs carnivore) on energy charge and nucleotide composition inHyas araneus larvae. ACTA ACUST UNITED AC 1992. [DOI: 10.1007/bf02366210] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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31
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Johnson TP, Johnston IA, Moon TW. Temperature and the energy cost of oscillatory work in teleost fast muscle fibres. Pflugers Arch 1991; 419:177-83. [PMID: 1961688 DOI: 10.1007/bf00373004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Bundles of 20-30 fast muscle fibres were isolated from the abdominal myotomes of the short-horned sculpin (Myoxocephalus scorpius L.). The energy cost of contraction was measured during oscillatory work at 4 degrees C and 15 degrees C following treatment with iodoacetate and nitrogen gas to block glycolysis and aerobic metabolism. Isolated fibres were subjected to sinusoidal length changes about in situ resting length and stimulated at a selected phase in the strain cycle. Preliminary experiments with untreated preparations established the strain amplitude and stimulation parameters required to maximize work output over a range of cycle frequencies at 4 degrees C and 15 degrees C. Following oscillatory work, treated preparations were rapidly frozen, freeze-dried and the concentrations of phosphocreatine (PCr), creatine, adenosine 5'-triphosphate (ATP), adenosine 5'-di- and mono-phosphate and inosine 5-monophosphate measured by high performance liquid chromatography. The concentration of PCr declined in proportion to the total work done for up to 64 cycles without a significant change in ATP. Maximum power output was produced at a cycle frequency of 5 Hz at 4 degrees C (14-18 W/kg) and 17 Hz at 15 degrees C (23-27 W/kg). The rate of utilization of PCr per cycle was independent of temperature. However, since work per cycle was higher at 4 degrees C (2.7-3.7 mJ/g wet weight) than 15 degrees C (1.2-1.6 mJ/g wet weight), the energetic cost of contraction decreased with increasing temperature.
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Affiliation(s)
- T P Johnson
- Gatty Marine Laboratory, Department of Biology and Preclinical Medicine, University of St. Andrews, Fife, Scotland, UK
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33
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Schmidt H, Wegener G. Glycogen phosphorylase in fish muscle: demonstration of three interconvertible forms. THE AMERICAN JOURNAL OF PHYSIOLOGY 1990; 258:C344-51. [PMID: 2106266 DOI: 10.1152/ajpcell.1990.258.2.c344] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
White skeletal muscle of crucian carp contains a single isoenzyme of glycogen phosphorylase, which was purified approximately 300-fold to a specific activity of approximately 13 mumol.min-1.mg protein-1 (assayed in the direction of glycogen breakdown at 25 degrees C). Tissue extracts of crucian muscle produced three distinct peaks of phosphorylase activity when separated on DEAE-Sephacel. Peaks 1 and 3 were identified, in terms of kinetic properties and by interconversion experiments, as phosphorylase b and a, respectively. Peak 2 was shown to be a phospho-dephospho hybrid. The three interconvertible forms of phosphorylase were purified and shown to be dimeric molecules at 20 degrees C. At 5 degrees C, a and the hybrid tended to form tetramers. The Mr of the subunit was estimated to be 96,400 from sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The hybrid is kinetically homogeneous, and its kinetic properties are intermediate between those of b and a forms. The b, hybrid, and a forms of phosphorylase can be isolated from rapidly frozen muscle of crucian but in different proportions, depending on whether fish were anesthetized or forced to muscular activity for 20 s. Muscle of anesthetized crucian had 36, 36, and 28% of phosphorylase b, hybrid, and a forms, respectively, whereas the corresponding values for exercised fish were 12, 37, and 51%. Results suggest that three interconvertible forms of phosphorylase exist simultaneously in crucian muscle and that hybrid phosphorylase is active in contracting muscle in vivo.
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Affiliation(s)
- H Schmidt
- Institut für Zoologie, Johannes Gutenberg-Universität Mainz, Federal Republic of Germany
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Harms J, Moal J, Le Coz J, Daniel J, Samain J. Nucleotide composition and energy charge in growing and starving zoea I of Carcinus maenas (Decapoda: portunidae). ACTA ACUST UNITED AC 1990. [DOI: 10.1016/0305-0491(90)90396-b] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Persistent production of hypoxanthine in rat skeletal muscle causes prolonged hyperuricemia after an exhaustive exercise. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 1989; 253A:369-74. [PMID: 2624215 DOI: 10.1007/978-1-4684-5673-8_60] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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38
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Mutungi G, Johnston IA. Influence of pH and temperature on force development and shortening velocity in skinned muscle fibres from fish. FISH PHYSIOLOGY AND BIOCHEMISTRY 1988; 5:257-262. [PMID: 24226787 DOI: 10.1007/bf01874803] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Three species of fish were studied: Atlantic cod (Gadus morhua), sculpin (Myoxocephalus scorpius) (from the North Sea, temperature 2 to 12°C) andNotothenia neglecta (from Antarctica, temperature -2 to +2°C). Single fast muscle fibres were isolated from anterior myotomes and skinned with detergent in order to directly determine the effects of pH and temperature on force production and shortening velocity.In all species maximum force production (Po) was independent of pH over the range 7.3-8.0. Decreasing the pH from 7.3 to 6.6 reduced maximum force by 28% in fibres fromG. morhua andN. neglecta but had no effect on fibres fromM. scorpius. The depression in maximum force with acidosis was accompanied by a proportional decrease in stiffness and an increase in the rate of force recovery after stretch.Unloaded contraction velocity of cod fibres (Vmax) showed a pH optimum at around pH 7.6 decreasing by 31% at pH 6.6. Vmax of fibres from the other species was independent of pH over the range 6.6-8.0.The effects of pH on Po and Vmax were similar at 0 and 10°C. Thus for maximally activated fibres both force and contraction velocity are independent of temperature induced changes in pH. In some species acidosis depresses contractility and is likely to be a contributory factor to muscle fatigue.
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Affiliation(s)
- G Mutungi
- Gatty Marine Laboratory, Department of Biology & Preclinical Medicine, University of St Andrews, KY16 8LB, Fife, Scotland
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Wright PA, Wood CM. Muscle ammonia stores are not determined by pH gradients. FISH PHYSIOLOGY AND BIOCHEMISTRY 1988; 5:159-162. [PMID: 24226675 DOI: 10.1007/bf01875704] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
The theory of non-ionic diffusion predicts that ammonia will distribute between intracellular and extracellular tissue compartments according to transmembrane pH gradients. The distribution of ammonia and(14)C-DMO were compared in white muscle and plasma of rainbow trout (Salmo gairdneri) at rest, and following exhaustive exercise. Under both experimental conditions, intracellular ammonia levels far exceeded those predicted by transmembrane pH gradients. Calculated equilibrium potentials for[Formula: see text]) were very close to published resting values of membrane potential Em in fish white muscle. We conclude that NH 4 (+) is permeable across cell membranes and that intracellular ammonia stores are not determined by pH gradients.
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Affiliation(s)
- P A Wright
- Department of Zoology, University of British Columbia, V6T 2A9, Vancouver, British Columbia, Canada
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40
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Mommsen TP, Hochachka PW. The purine nucleotide cycle as two temporally separated metabolic units: a study on trout muscle. Metabolism 1988; 37:552-6. [PMID: 3374321 DOI: 10.1016/0026-0495(88)90170-9] [Citation(s) in RCA: 85] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Experimental results on fast-twitch muscle of rainbow trout following exercise and during subsequent recovery lead us to a reinterpretation for the function of the components of the purine nucleotide cycle (PNC). Exhaustive exercise depletes tissue ATP by more than 90% and results in a stoichiometric gain in IMP and ammonium ions. Simultaneously, white-muscle aspartate decreases by half, but its maximum contribution can account for less than 2% of the accumulated ammonium. Of the three enzymes of the purine nucleotide cycle, AMP deaminase, adenylosuccinate synthetase and adenylosuccinate lyase, only AMP deaminase is functional during exhaustive exercise. During the slow (greater than 15 hour) recovery, AMP deaminase is effectively shut off, while the other two enzymes replenish the adenylate pool. At all times, a tight inverse correlation exists between ATP and IMP concentrations. Tissue ammonium and malate supply the required aspartate. Theoretical treatment with special attention to proton dynamics in a potentially anaerobic tissue also leads to the conclusion that rather than constituting a true cycle, distinct parts of the PNC are temporally segregated. We hypothesize that during periods of high energy demand, exclusively AMP deaminase is activated as a means (1) to push the myokinase reaction toward ATP synthesis, (2) to supply allosteric effectors, and (3) to remove some of the accumulating protons through the formation of ammonium, all at the expense of the adenylate pool. The process leading to its replenishment, which involves the production of two protons and the consumption of a high-energy phosphate, can be active during aerobic recovery only.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- T P Mommsen
- Department of Zoology, University of British Columbia, Vancouver, Canada
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Giesy JP. Phosphoadenylate concentrations and adenylate energy charge of largemouth bass (Micropterus salmoides): relationship with condition factor and blood cortisol. COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY. A, COMPARATIVE PHYSIOLOGY 1988; 90:367-77. [PMID: 2901306 DOI: 10.1016/0300-9629(88)90204-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
1. Concentrations of phosphoadenylate nucleotides and adenylate energy charge in the dorsal muscle and blood of largemouth bass from a reservoir receiving heated effluent were investigated. These values were compared with the length, weight, body condition and blood cortisol concentrations. 2. Body condition of the largemouth bass ranged from 1043 to 2544, reflecting the range of condition due to starvation of some fish in the population. 3. Blood cortisol concentrations ranged from 4.0 to 23.1 micrograms/100 ml with a mean of 6.3 micrograms/100 ml. 4. The adenylate energy charge of muscle (MATP) and blood ranged from 0.37 to 0.98 and 0.74 to 0.99, respectively. 5. Blood cortisol concentration was positively correlated with body condition but not correlated with the adenylate energy charge of either blood or muscle. 6. Blood cortisol concentration was negatively correlated with concentration of adenylates in both muscle and blood.
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Affiliation(s)
- J P Giesy
- Department of Fisheries and Wildlife, Michigan State University, E. Lansing 48824
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Wieser W, Lackner R, Hinterleitner S, Platzer U. Distribution and properties of lactate dehydrogenase isoenzymes in red and white muscle of freshwater fish. FISH PHYSIOLOGY AND BIOCHEMISTRY 1987; 3:151-162. [PMID: 24233443 DOI: 10.1007/bf02180417] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
The distribution and kinetics of LDH isoenzymes in red and white muscles of 5 species of salmonids, 4 species of cyprinids and one coregonid species were studied. In all species the white muscles are characterized by the occurrence of only the most cathodic isoenzymes, or groups of isoenzymes. The red muscles contained either the full set of isoenzymes (cyprinids) or a selection in which the anodic forms dominated (salmonids, coregonid). The most striking difference between the two types of muscle was met inCoregonus sp. The temperature profiles of pyruvate affinity are similar in all species of fish studied. On the other hand, Km(pyr) values and degree of pyruvate inhibition are closely related and vary greatly with temperature, with the taxonomic position (and thus biology) of the species, and with electrophoresic mobility of the isoenzyme. Highest affinity and strongest inhibition occurred in the anodic (H4) isoenzymes of cyprinids at low temperature; lowest affinity and zero inhibition in the cathodic isoenzymes (Mα4 → Mβ4) of salmonids and coregonids at high temperature. In salmonids the more recently duplicated loci of the M-group of isoenzymes possess identical Km values at all temperatures, whereas the two older M and H loci differ greatly in this respect. Thus the more recent duplication of LDH loci in salmonids and coregonids may be seen as a mechanism by which the tetramers required for LDH activity can be constructed from more closely related subunits than are provided by the older M and H loci.Some problems in connection with the determination of the kinetic constants of the lactate oxidase reaction are discussed and it is suggested that an alkaline, pyruvate trapping system provides conditions which are more realistic than those of other assay systems. The Km(lactate) values found are in the biological range and, at 20°C, provide further circumstantial evidence that the red muscles of fish should be capable of oxidizing the lactate produced by the white muscles during strenuous exercise. At 4°C the Km(lactate) values are abnormally high in all muscle preparations and thus are not correlated with the Km(pyruvate) values which are lowest at this temperature.
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Affiliation(s)
- W Wieser
- Institut für Zoologie, Abteilung Zoophysiologie, Universität Innsbruck, Technikerstraβe 25, A-6020, Innsbruck, Austria
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Randall DJ, Wright PA. Ammonia distribution and excretion in fish. FISH PHYSIOLOGY AND BIOCHEMISTRY 1987; 3:107-120. [PMID: 24233438 DOI: 10.1007/bf02180412] [Citation(s) in RCA: 70] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
This paper reviews the literature concerning ammonia production, storage and excretion in fish. Ammonia is the end product of protein catabolism and is stored in the body of fish in high concentrations relative to basal excretion rates. Ammonia, if allowed to accumulate, is toxic and is converted to less toxic compounds or excreted. Like other weak acids and bases, ammonia is distributed between tissue compartments in relation to transmembrane pH gradients. NH3 is generally equilibrated between compartments but NH4 (+) is distributed according to pH. Ammonia is eliminated from the blood upon passage through the gills. The mechanisms of branchial ammonia excretion vary between different species of fish and different environments, and primarily involves NH3 passive diffusion and NH4 (+)/Na(+) exchange. Water chemistry near the gill surface may also be important to ammonia excretion, but a more accurate measurement of the NH3 gradient across the gill epithelium is required before a more detailed analysis of NH3 and NH4 (+) excretion can be made.
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Affiliation(s)
- D J Randall
- Department of Zoology, University of British Columbia, Vancouver, B.C., V6T 2A9
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Siau H, Ip YK. Activities of enzymes associated with phosphoenolpyruvate metabolism in the mudskippers, Boleophthalmus boddaerti and Periophthalmodon schlosseri. COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY. B, COMPARATIVE BIOCHEMISTRY 1987; 88:119-25. [PMID: 3677593 DOI: 10.1016/0305-0491(87)90089-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
1. PK and LDH activities in the muscle of Periophthalmodon schlosseri and Boleophthalmus boddaerti were at least 100-fold higher than their respective activities in the liver. 2. The ratio of PK:PEPCK in liver of B. boddaerti was smaller than that of P. schlosseri. 3. PK:PEPCK ratios in both fishes were intermediate between those of aerobic and anaerobic organisms. 4. MDH activity was higher than other enzymes assayed in the liver of both fishes. 5. The ratios of LDH:MDH in the liver of both mudskippers were comparable to those of anaerobic organisms. 6. AST was at least eight times more active than ALT in the liver of both fishes. 7. In the muscle of these mudskippers, the aspartate content was significantly less than that of alanine. 8. Exposure of these fishes to various experimental conditions led to changes in specific activities of PEPCK, LDH, AST and ALT.
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Affiliation(s)
- H Siau
- Department of Zoology, National University of Singapore, Kent Ridge
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Morris AS, Shearer JD, Forster J, Mastrofrancesco B, Henry W, Caldwell MD. The relationship of purine metabolism to the macrophage-mediated increase of high energy phosphates in skeletal muscle. J Surg Res 1986; 41:339-46. [PMID: 3773494 DOI: 10.1016/0022-4804(86)90046-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Previous investigations have demonstrated that the high energy phosphate and adenine nucleotide content of wounded tissue are decreased. Purine metabolism was investigated in incubated lambda-carrageenan wounded skeletal muscle and in muscle exposed to peritoneal macrophages or macrophage-conditioned media. Wounded muscle released predominately uric acid into the incubation medium; whereas, nonwounded muscle released inosine, hypoxanthine, and xanthine as well as uric acid. Macrophages incubated with nonwounded muscle changed the purine release pattern toward one of wounded muscle. The conversion of inosine to allantoin and uric acid by macrophages increased linearly with the addition of up to 1 X 10(7) macrophages per incubation. Muscles incubated in macrophage-conditioned media had a decreased release of inosine and hypoxanthine and higher tissue levels of creatine phosphate, ATP, ADP, AMP, and adenosine compared to muscles incubated in standard media. These data suggest that the macrophage determines the pattern of purine release from wounded skeletal muscle in the incubated system and that in conditioned media a high energy phosphate promoting factor may exert its effect by mechanisms that augment the adenine purine pool.
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Ottolenghi C, Puviani AC, Gavioli ME, Brighenti L. Epinephrine effect on glycogen phosphorylase activity in catfish liver and muscles. Gen Comp Endocrinol 1986; 61:469-75. [PMID: 3956998 DOI: 10.1016/0016-6480(86)90235-2] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
In catfish, the percentage of the active (a) form of glycogen phosphorylase with respect to the total (a + b) form varied in control slices from about 90% to 65% and 20%, respectively for liver, red, and white muscles. Epinephrine added to the incubation medium of liver and white muscle slices caused a significant increase in the specific activity of phosphorylase a in liver and white muscle, but not in red muscle. In liver slices epinephrine showed its effect from the concentration of 3.5 X 10(-8) M. The increase of enzyme activity explains the lowering of the glycogen level in liver and white muscle induced by epinephrine.
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49
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Milligan CL, Farrell TP. Extracellular and intracellular acid-base status following strenuous activity in the sea raven (Hemitripterus americanus). J Comp Physiol B 1986. [DOI: 10.1007/bf00691045] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Wieser W, Koch F, Drexel E, Platzer U. “Stress” reactions in teleosts: Effects of temperature and activity on anaerobic energy production in roach (Rutilus rutilus L.). ACTA ACUST UNITED AC 1986. [DOI: 10.1016/0300-9629(86)90085-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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