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Boonsanit P, Chanchao C, Pairohakul S. Effects of hypo-osmotic shock on osmoregulatory responses and expression levels of selected ion transport-related genes in the sesarmid crab Episesarma mederi (H. Milne Edwards, 1853). Comp Biochem Physiol A Mol Integr Physiol 2024; 288:111541. [PMID: 37935274 DOI: 10.1016/j.cbpa.2023.111541] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2023] [Revised: 10/29/2023] [Accepted: 11/01/2023] [Indexed: 11/09/2023]
Abstract
This study examined the osmoregulatory responses to hypo-osmotic shock in the commercially and ecologically important crab Episesarma mederi (H. Milne Edwards, 1853). After the acclimation for one week at a salinity of 25 PSU, Adult males E. mederi were immediately exposed to salinities of 5 PSU and 25 PSU (the control group). The time course of changes in haemolymph osmolality, gill Na+/K+ ATPase (NKA) activity, oxygen uptake rates, and mRNA expression levels of ion-transport related genes, including the NKA-α subunit, V-type H+ATPase (VT) and Na+/K+/2Cl-(NKCC), were determined. The results showed that E. mederi was a strong hyperosmoregulator after exposure to 5 PSU, achieved by modulations of NKA activity in their posterior gills rather than the anterior gills. The crabs acclimated to 5 PSU increased oxygen uptake, especially during the initial exposure, reflecting increased energetic costs for osmotic stress responses. In the posterior gills, the NKA activities of the crabs acclimated to 5 PSU at 3, 72 and 168 h were significantly higher than those in the control group. Elevated NKA-α subunit expression levels were detected at 6 h and 12 h. Increased expression levels of VT and NKCC were identified at 6 h and 12 h, respectively. Our results indicate that elevated gill NKA activity at 3 h could result from enzyme activity and kinetic alterations. On the other hand, the gill NKA activity at 72 and 168 h was sustained by elevated NKA-α subunit expression. Hence, these adaptive responses in osmoregulation enable the crabs to withstand hypo-osmotic challenges and thrive in areas of fluctuating salinity in mangroves and estuaries.
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Affiliation(s)
- Phurich Boonsanit
- Department of Marine Science, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand
| | - Chanpen Chanchao
- Department of Biology, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand
| | - Supanut Pairohakul
- Department of Marine Science, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand.
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Griffith MB. Toxicological perspective on the osmoregulation and ionoregulation physiology of major ions by freshwater animals: Teleost fish, crustacea, aquatic insects, and Mollusca. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY 2017; 36:576-600. [PMID: 27808448 PMCID: PMC6114146 DOI: 10.1002/etc.3676] [Citation(s) in RCA: 88] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/2016] [Revised: 04/11/2016] [Accepted: 11/01/2016] [Indexed: 05/21/2023]
Abstract
Anthropogenic sources increase freshwater salinity and produce differences in constituent ions compared with natural waters. Moreover, ions differ in physiological roles and concentrations in intracellular and extracellular fluids. Four freshwater taxa groups are compared, to investigate similarities and differences in ion transport processes and what ion transport mechanisms suggest about the toxicity of these or other ions in freshwater. Although differences exist, many ion transporters are functionally similar and may belong to evolutionarily conserved protein families. For example, the Na+ /H+ -exchanger in teleost fish differs from the H+ /2Na+ (or Ca2+ )-exchanger in crustaceans. In osmoregulation, Na+ and Cl- predominate. Stenohaline freshwater animals hyperregulate until they are no longer able to maintain hypertonic extracellular Na+ and Cl- concentrations with increasing salinity and become isotonic. Toxic effects of K+ are related to ionoregulation and volume regulation. The ionic balance between intracellular and extracellular fluids is maintained by Na+ /K+ -adenosine triphosphatase (ATPase), but details are lacking on apical K+ transporters. Elevated H+ affects the maintenance of internal Na+ by Na+ /H+ exchange; elevated HCO3- inhibits Cl- uptake. The uptake of Mg2+ occurs by the gills or intestine, but details are lacking on Mg2+ transporters. In unionid gills, SO42- is actively transported, but most epithelia are generally impermeant to SO42- . Transporters of Ca2+ maintain homeostasis of dissolved Ca2+ . More integration of physiology with toxicology is needed to fully understand freshwater ion effects. Environ Toxicol Chem 2017;36:576-600. Published 2016 Wiley Periodicals Inc. on behalf of SETAC. This article is a US government work and, as such, is in the public domain in the United States of America.
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Affiliation(s)
- Michael B. Griffith
- Office of Research and Development, National Center for Environmental Assessment, US Environmental Protection Agency, Cincinnati, Ohio, USA
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Larsen EH, Deaton LE, Onken H, O'Donnell M, Grosell M, Dantzler WH, Weihrauch D. Osmoregulation and Excretion. Compr Physiol 2014; 4:405-573. [DOI: 10.1002/cphy.c130004] [Citation(s) in RCA: 127] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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Henry RP, Lucu Č, Onken H, Weihrauch D. Multiple functions of the crustacean gill: osmotic/ionic regulation, acid-base balance, ammonia excretion, and bioaccumulation of toxic metals. Front Physiol 2012; 3:431. [PMID: 23162474 PMCID: PMC3498741 DOI: 10.3389/fphys.2012.00431] [Citation(s) in RCA: 222] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2012] [Accepted: 10/24/2012] [Indexed: 12/19/2022] Open
Abstract
The crustacean gill is a multi-functional organ, and it is the site of a number of physiological processes, including ion transport, which is the basis for hemolymph osmoregulation; acid-base balance; and ammonia excretion. The gill is also the site by which many toxic metals are taken up by aquatic crustaceans, and thus it plays an important role in the toxicology of these species. This review provides a comprehensive overview of the ecology, physiology, biochemistry, and molecular biology of the mechanisms of osmotic and ionic regulation performed by the gill. The current concepts of the mechanisms of ion transport, the structural, biochemical, and molecular bases of systemic physiology, and the history of their development are discussed. The relationship between branchial ion transport and hemolymph acid-base regulation is also treated. In addition, the mechanisms of ammonia transport and excretion across the gill are discussed. And finally, the toxicology of heavy metal accumulation via the gill is reviewed in detail.
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Affiliation(s)
- Raymond P. Henry
- Department of Biological Sciences, Auburn UniversityAuburn, AL, USA
| | - Čedomil Lucu
- Center for Marine Research Rovinj, Institute Ruđder Bošković ZagrebRovinj, Croatia
- Department of Aquaculture, University of DubrovnikDubrovnik, Croatia
| | - Horst Onken
- Department of Biological Sciences, Wagner CollegeStaten Island, NY, USA
| | - Dirk Weihrauch
- Department of Biological Sciences, University of ManitobaWinnipeg, MB, Canada
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McNamara JC, Faria SC. Evolution of osmoregulatory patterns and gill ion transport mechanisms in the decapod Crustacea: a review. J Comp Physiol B 2012; 182:997-1014. [DOI: 10.1007/s00360-012-0665-8] [Citation(s) in RCA: 120] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2011] [Revised: 04/02/2012] [Accepted: 04/04/2012] [Indexed: 10/28/2022]
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Weber AK, Pirow R. Physiological responses of Daphnia pulex to acid stress. BMC PHYSIOLOGY 2009; 9:9. [PMID: 19383148 PMCID: PMC2689847 DOI: 10.1186/1472-6793-9-9] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/29/2008] [Accepted: 04/21/2009] [Indexed: 12/30/2022]
Abstract
BACKGROUND Acidity exerts a determining influence on the composition and diversity of freshwater faunas. While the physiological implications of freshwater acidification have been intensively studied in teleost fish and crayfish, much less is known about the acid-stress physiology of ecologically important groups such as cladoceran zooplankton. This study analyzed the extracellular acid-base state and CO2 partial pressure (P(CO2)), circulation and ventilation, as well as the respiration rate of Daphnia pulex acclimated to acidic (pH 5.5 and 6.0) and circumneutral (pH 7.8) conditions. RESULTS D. pulex had a remarkably high extracellular pH of 8.33 and extracellular P(CO2) of 0.56 kPa under normal ambient conditions (pH 7.8 and normocapnia). The hemolymph had a high bicarbonate concentration of 20.9 mM and a total buffer value of 51.5 meq L(-1) pH(-1). Bicarbonate covered 93% of the total buffer value. Acidic conditions induced a slight acidosis (DeltapH = 0.16-0.23), a 30-65% bicarbonate loss, and elevated systemic activities (tachycardia, hyperventilation, hypermetabolism). pH 6.0 animals partly compensated the bicarbonate loss by increasing the non-bicarbonate buffer value from 2.0 to 5.1 meq L(-1) pH(-1). The extracellular P(CO2) of pH 5.5 animals was significantly reduced to 0.33 kPa, and these animals showed the highest tolerance to a short-term exposure to severe acid stress. CONCLUSION Chronic exposure to acidic conditions had a pervasive impact on Daphnia's physiology including acid-base balance, extracellular PCO2, circulation and ventilation, and energy metabolism. Compensatory changes in extracellular non-bicarbonate buffering capacity and the improved tolerance to severe acid stress indicated the activation of defense mechanisms which may result from gene-expression mediated adjustments in hemolymph buffer proteins and in epithelial properties. Mechanistic analyses of the interdependence between extracellular acid-base balance and CO2 transport raised the question of whether a carbonic anhydrase (CA) is involved in the catalysis of the CO2-HCO3(-)-H(+) reaction, which led to the discovery of 31 CA-genes in the genome of D. pulex.
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Affiliation(s)
- Anna K Weber
- Institute of Zoophysiology, University of Münster, Münster, Germany.
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Bianchini A, Wood CM. Sodium uptake in different life stages of crustaceans: the water fleaDaphnia magnaStrauss. J Exp Biol 2008; 211:539-47. [DOI: 10.1242/jeb.009175] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
SUMMARYThe concentration-dependent kinetics and main mechanisms of whole-body Na+ uptake were assessed in neonate and adult water flea Daphnia magna Strauss acclimated to moderately hard water (0.6 mmol l–1 NaCl, 1.0 mmol l–1 CaCO3 and 0.15 mmol l–1 MgSO4·7H2O; pH 8.2). Whole-body Na+ uptake is independent of the presence of Cl– in the external medium and kinetic parameters are dependent on the life stage. Adults have a lower maximum capacity of Na+ transport on a mass-specific basis but a higher affinity for Na+ when compared to neonates. Based on pharmacological analyses,mechanisms involved in whole-body Na+ uptake differ according to the life stage considered. In neonates, a proton pump-coupled Na+channel appears to play an important role in the whole-body Na+uptake at the apical membrane. However, they do not appear to contribute to whole-body Na+ uptake in adults, where only the Na+channel seems to be present, associated with the Na+/H+exchanger. In both cases, carbonic anhydrase contributes by providing H+ for the transporters. At the basolateral membrane of the salt-transporting epithelia of neonates, Na+ is pumped from the cells to the extracellular fluid by a Na+,K+-ATPase and a Na+/Cl– exchanger whereas K+ and Cl– move through specific channels. In adults, a Na+/K+/2Cl– cotransporter replaces the Na+/Cl– exchanger. Differential sensitivity of neonates and adults to iono- and osmoregulatory toxicants, such as metals, are discussed with respect to differences in whole-body Na+ uptake kinetics, as well as in the mechanisms of Na+ transport involved in the whole-body Na+ uptake in the two life stages.
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Affiliation(s)
- Adalto Bianchini
- Fundação Universidade Federal do Rio Grande, Departamento de Ciências Fisiológicas, Campus Carreiros, Av. Itália s/n,96.201-900 Rio Grande, RS, Brazil
| | - Chris M. Wood
- McMaster University, Department of Biology, 1280 Main Street West, Hamilton,ON, L8S 4K1, Canada
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Freire CA, Onken H, McNamara JC. A structure-function analysis of ion transport in crustacean gills and excretory organs. Comp Biochem Physiol A Mol Integr Physiol 2007; 151:272-304. [PMID: 17604200 DOI: 10.1016/j.cbpa.2007.05.008] [Citation(s) in RCA: 224] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2006] [Revised: 05/08/2007] [Accepted: 05/11/2007] [Indexed: 11/29/2022]
Abstract
Osmotic and ionic regulation in the Crustacea is mostly accomplished by the multifunctional gills, together with the excretory organs. In addition to their role in gas exchange, the gills constitute organs of active, transepithelial, ion transport, an activity of major importance that underlies many essential physiological functions like osmoregulation, calcium homeostasis, ammonium excretion and extracellular pH regulation. This review focuses on structure-function relationships in crustacean gills and excretory effectors, from the organ to molecular levels of organization. We address the diversity of structural architectures encountered in different crustacean gill types, and in constituent cell types, before examining the physiological mechanisms of Na(+), Cl(-), Ca(2+) and NH(4)(+) transport, and of acid-base equivalents, based on findings obtained over the last two decades employing advanced techniques. The antennal and maxillary glands constitute the principal crustacean excretory organs, which have received less attention in functional studies. We examine the diversity present in antennal and maxillary gland architecture, highlighting the structural similarities between both organ types, and we analyze the functions ascribed to each glandular segment. Emphasis is given to volume and osmoregulatory functions, capacity to produce dilute urine in freshwater crustaceans, and the effect of acclimation salinity on urine volume and composition. The microanatomy and diversity of function ascribed to gills and excretory organs are appraised from an evolutionary perspective, and suggestions made as to future avenues of investigation that may elucidate evolutionary and adaptive trends underpinning the invasion and exploitation of novel habitats.
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Affiliation(s)
- Carolina A Freire
- Departamento de Fisiologia, Setor de Ciências Biológicas, Universidade Federal do Paraná, Curitiba, PR, 81531-990, Brazil.
| | - Horst Onken
- Department of Biological Sciences, Wagner College, Staten Island, NY 10301, USA
| | - John C McNamara
- Departamento de Biologia, FFCLRP, Universidade de São Paulo, Ribeirão Preto, SP, 14040-901, Brazil
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Abstract
SUMMARYThe emphasis in this review will be on Na+ absorption across the skin and gills of vertebrates and the gills of crustaceans. However, some recent studies of Cl– uptake, especially in crustaceans, will also be described.
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Affiliation(s)
- Leonard B Kirschner
- School of Biological Sciences, Washington State University, Pullman, WA 99164-4236, USA.
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Abstract
Recently, three proton pump inhibitors were shown to have no effect on proton excretion and little on Na uptake in tapwater-adapted (TW) crayfish, while all three reduced Na-H exchange in salt-depleted (SD) animals. It appeared that the exchange was mediated by the Na channel-H pump in SD crayfish but not in TW animals. An alternative, a 2Na-1H exchanger, might function in the latter. To test this, the effects of amiloride (AM) and ethylisopropyl AM (EIPA) on Na fluxes were observed. AM inhibits the Na channel but is a much weaker blocker of Na-H exchangers. In contrast, EIPA inhibits exchangers but acts weakly on the Na channel. If an exchanger functions in TW crayfish, we should expect EIPA to block Na influx in them with AM having a weaker action. The reverse should be true in SD animals. Experimental data showed that EIPA was a potent inhibitor of Na influx in TW crayfish with half-maximal inhibition at about 0.2 microM. However, AM proved to be equipotent. In SD crayfish, EIPA was as effective as in TW animals, and again AM was equally potent. The data fail to show the expected differential action. Therefore, AM and its analogues cannot be used to distinguish between the two models of Na-H exchange in crayfish.
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Affiliation(s)
- Leonard B Kirschner
- School of Biological Sciences, Washington State University, Pullman, WA 99164-4236, USA.
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Schmieder S, Lindenthal S, Ehrenfeld J. Cloning and characterisation of amphibian ClC-3 and ClC-5 chloride channels. BIOCHIMICA ET BIOPHYSICA ACTA 2002; 1566:55-66. [PMID: 12421537 DOI: 10.1016/s0005-2736(02)00594-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Amphibians have provided important model systems to study transepithelial transport, acid-base balance and cell volume regulation. Several families of chloride channels and transporters are involved in these functions. The purpose of this review is to report briefly on some of the characteristics of the chloride channels so far reported in amphibian epithelia, and to focus on recently cloned members of the ClC family and their possible physiological roles. The electrophysiological characterisation, distribution, localisation and possible functions are reviewed and compared to their mammalian orthologs.
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Affiliation(s)
- S Schmieder
- Laboratoire de Physiologie des Membranes Cellulaires, Université de Nice-Sophia Antipolis, UMR 6078/CNRS, 284 Chemin du Lazaret, BP 68, Villefranche sur Mer, France
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Grosell M, Nielsen C, Bianchini A. Sodium turnover rate determines sensitivity to acute copper and silver exposure in freshwater animals. Comp Biochem Physiol C Toxicol Pharmacol 2002; 133:287-303. [PMID: 12356534 DOI: 10.1016/s1532-0456(02)00085-6] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The mechanisms of acute copper and silver toxicity in freshwater organisms appear similar. Both result in inhibition of branchial sodium (and chloride) uptake initiating a cascade of effects leading to mortality. The inhibition of the branchial Na/K-ATPase in the basolateral membrane is generally accepted as the key component responsible for the reduced sodium uptake. We propose that branchial carbonic anhydrase and the apical sodium channel may also be important targets for both copper and silver exposure. Several attempts have been made to predict metal sensitivity. A prominent example is the geochemical-biotic ligand model. The geochemical-biotic ligand modeling approach has been successful in explaining variations in tolerance to metal exposure for specific groups of animals exposed at different water chemistries. This approach, however, cannot explain the large observed variation in tolerance to these metals amongst different groups of freshwater animals (i.e. Daphnia vs. fish). Based on the detailed knowledge of physiological responses to acute metal exposure, the present review offers an explanation for the observed variation in tolerance. Smaller animals are more sensitive than large animals because they exhibit higher sodium turnover rates. The same relative inhibition of sodium uptake results in faster depletion of internal sodium in animals with higher sodium turnover. We present a way to improve predictions of acute metal sensitivity, noting that sodium turnover rate is the key predictor for variation in acute copper and silver toxicity amongst groups of freshwater animals. We suggest that the presented sodium turnover model is used in conjunction with the Biotic Ligand Model for risk management decisions.
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Affiliation(s)
- Martin Grosell
- Copenhagen University, The August Krogh Institute, Zoophysiological Laboratory, Universitetsparken 13, DK-2100 Copenhagen Ø, Denmark.
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