1
|
Ceron FJM, Prodocimo V, Freire CA. Distribution of Na +/K +-ATPase-immunoreactive ionocytes varies between two superorders of ray-finned fish: Ostariophysi and Acanthopterygii. FISH PHYSIOLOGY AND BIOCHEMISTRY 2021; 47:1063-1071. [PMID: 33999342 DOI: 10.1007/s10695-021-00963-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/2021] [Accepted: 05/04/2021] [Indexed: 06/12/2023]
Abstract
Ray-finned fishes of the superorder Ostariophysi are primarily freshwater (FW), and normally stenohaline. Differently, fishes of the superorder Acanthopterygii are essentially marine, and frequently euryhaline, with some secondary FW. Na+/K+-ATPase-immunoreactive ionocytes were localized in the branchial epithelia of 4 species of Ostariophysi and 3 of Acanthopterygii. The Ostariophysi grass carp (Ctenopharyngodon idella, Cypriniformes), twospot Astyanax (Astyanax bimaculatus) and piracanjuba (Brycon orbignyanus), Characiformes, and the jundiá (Rhamdia quelen, Siluriformes), all from FW, displayed ionocytes in the filament plus secondary lamellae (F + SL). In their turn, all the three species of Acanthopterygii showed immunoreactive ionocytes in the filaments only (F). They were the Nile tilapia (Oreochromis niloticus, Cichliformes) in FW, the dog snapper (Lutjanus jocu, Perciformes) in seawater (SW), and the green puffer (Sphoeroides greeleyi, Tetraodontiformes) in SW. Ionocytes normally extend their distribution to the secondary lamellae (F + SL) in Ostariophysi. In Acanthopterygii, we find more plasticity: ionocytes are more frequently restricted to the filament in SW, but also spread to SL in FW. It may be that the occurrence of ionocytes in SL is the ancestral condition, but some euryhaline acanthopterygians rely on the space of the SL for placement of additional ionocytes when in FW absorbing salt. Our study contributed to the identification of the pattern of ionocyte distribution in gills of Ostariophysi in respect to that of Acanthopterygii.
Collapse
Affiliation(s)
- F Juliane M Ceron
- Departamento de Fisiologia, Setor de Ciências Biológicas, Universidade Federal do Paraná, Curitiba, Paraná, 81531-980, Brazil
| | - Viviane Prodocimo
- Departamento de Fisiologia, Setor de Ciências Biológicas, Universidade Federal do Paraná, Curitiba, Paraná, 81531-980, Brazil
| | - Carolina A Freire
- Departamento de Fisiologia, Setor de Ciências Biológicas, Universidade Federal do Paraná, Curitiba, Paraná, 81531-980, Brazil.
| |
Collapse
|
2
|
Lucu Č. Hypoxia attenuate ionic transport in the isolated gill epithelium of Carcinus maenas. J Comp Physiol B 2020; 190:391-401. [PMID: 32333115 DOI: 10.1007/s00360-020-01277-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2019] [Revised: 03/31/2020] [Accepted: 04/08/2020] [Indexed: 12/18/2022]
Abstract
The gills are osmorespiratory organs of aquatic organisms and the prime target of environmentally induced hypoxia. We have studied the impact of severe hypoxia (0.5 mg O2/L) on the ionic transport across posterior gills of Carcinus maenas acclimated to 12 ppt seawater (DSW). The short-circuit current (Isc) across hemilamellae from gills i.e. active ion transport was studied in micro Ussing chambers. Hypoxia induced by deoxygenation of the basolateral side, and not the apical side, resulted in time-dependent inhibition of Isc and full recovery of Isc after reoxygenation. Exposure of the crabs to severe 7 h hypoxia decreased the specific activity of Na+,K+-ATPase in the gills by 36%. Full recovery of enzyme activity occurred in fasted crabs after 3 days of reoxygenation. The intensity of Western blotting bands was not different in the gills of oxygenated, hypoxic and reoxygenated crabs. The reversible, nonspecific blocker of K+ channels Cs and hypoxia inhibited over 90% of Isc which is after reoxygenation fully recovered. The specific blocker of Cl- channels NPPB [5-nitro-2-(3-phenylpropylamino)benzoic acid] blocked Isc by 68.5%. Only the rest of not inhibited Isc in aerated saline was blocked by hypoxia and recovered after reoxygenation. The activity of the antioxidant enzyme catalase was not changed during hypoxia and reoxygenation kept the high enzyme activity in the gills at the level of crabs acclimated to DSW. As a response to hypoxia the presence of 2 mM H2O2 induce an initial slight transient decrease of Isc followed by a rise and after reoxygenation fully recovered Isc. Incubation of hemilamellae with the antioxidant derivative Trolox did not affect the inhibition of Isc by hypoxia.
Collapse
Affiliation(s)
- Čedomil Lucu
- Center for Marine Research, Institute Ruđer Bošković, Rovinj, Zagreb, Croatia.
- Alfred Wegener-Institute Helmholtz Centre for Polar and Marine Research, Wadden Sea Station List, Sylt, Germany.
| |
Collapse
|
3
|
Giacomin M, Onukwufor JO, Schulte PM, Wood CM. Ionoregulatory aspects of the hypoxia-induced osmorespiratory compromise in the euryhaline Atlantic killifish (Fundulus heteroclitus): the effects of salinity. J Exp Biol 2020; 223:jeb.216309. [DOI: 10.1242/jeb.216309] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2019] [Accepted: 05/26/2020] [Indexed: 12/20/2022]
Abstract
The osmorespiratory compromise is a physiological trade-off between the characteristics of the gill that promote respiratory gas-exchange and those that limit passive fluxes of ions and water with the environment. In hypoxia, changes in gill blood flow patterns and functional surface area that increase gas transfer can promote an exacerbation in ion and water fluxes. Our goal was to determine whether the osmorespiratory compromise is flexible, depending on environmental salinity (fresh, isosmotic and sea water) and oxygen levels (hypoxia) in euryhaline killifish, Fundulus heteroclitus. Plasma ion concentrations were minimally affected by hypoxia, indicating a maintenance of osmoregulatory homeostasis. In FW-killifish, hypoxia exposure reduced branchial Na+/K+-ATPase and NEM-sensitive-ATPase activities, as well as diffusive water flux rates. Unidirectional Na+ influx and Na+ efflux decreased during hypoxia in FW, but net Na+ flux remained unchanged. Net loss rates of Cl−, K+ and ammonia were also attenuated in hypoxia, suggesting both transcellular and paracellular reductions in permeability. These reductions appeared to be regulated phenomena as fluxes were restored immediately in normoxia. Na+ flux rates increased during hypoxia in 11 ppt, but decreased in 35 ppt, the latter suggesting a similar response to hypoxia as in FW. In summary, FW- and SW-killifish experience a reduction in gill permeability, as seen in other hypoxia-tolerant species. Fish acclimated to isosmotic salinity increased Na+ influx and efflux rates, as well as paracellular permeability in hypoxia, responses in accord with the predictions of the classic osmorespiratory compromise.
Collapse
Affiliation(s)
- Marina Giacomin
- Department of Zoology, The University of British Columbia, Vancouver, BC, V6T 1Z4, Canada
| | - John O. Onukwufor
- Department of Zoology, The University of British Columbia, Vancouver, BC, V6T 1Z4, Canada
- Department of Anesthesiology and Perioperative Medicine, University of Rochester Medical Center, Rochester, NY, 14642, USA
| | - Patricia M. Schulte
- Department of Zoology, The University of British Columbia, Vancouver, BC, V6T 1Z4, Canada
| | - Chris M. Wood
- Department of Zoology, The University of British Columbia, Vancouver, BC, V6T 1Z4, Canada
- Department of Biology, McMaster University, Hamilton, ON, L8S 4K1, Canada
| |
Collapse
|
4
|
Giacomin M, Bryant HJ, Val AL, Schulte PM, Wood CM. The osmorespiratory compromise: physiological responses and tolerance to hypoxia are affected by salinity acclimation in the euryhaline Atlantic killifish ( Fundulus heteroclitus). ACTA ACUST UNITED AC 2019; 222:jeb.206599. [PMID: 31488621 DOI: 10.1242/jeb.206599] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2019] [Accepted: 09/03/2019] [Indexed: 12/16/2022]
Abstract
The characteristics of the fish gill that maximize gas exchange are the same that promote diffusion of ions and water to and from the environment; therefore, physiological trade-offs are likely to occur. Here, we investigated how salinity acclimation affects whole-animal respiratory gas exchange during hypoxia using Fundulus heteroclitus, a fish that inhabits salt marshes where salinity and oxygen levels vary greatly. Salinity had marked effects on hypoxia tolerance, with fish acclimated to 11 and 35 ppt showing much longer time to loss of equilibrium (LOE) in hypoxia than 0 ppt-acclimated fish. Fish acclimated to 11 ppt (isosmotic salinity) exhibited the greatest capacity to regulate oxygen consumption rate (Ṁ O2 ) under hypoxia, as measured through the regulation index (RI) and P crit At 35 ppt, fish had a higher routine metabolic rate (RMR) but a lower RI than fish at 11 ppt, but there were no differences in gill morphology, ventilation or blood O2 transport properties between these groups. In contrast, 0 ppt-acclimated fish had the highest ventilation and lowest O2 extraction efficiency in normoxia and hypoxia, indicating a higher ventilatory workload in order to maintain similar levels of Ṁ O2 These differences were related to alterations in gill morphology, where 0 ppt-acclimated fish had the smallest lamellar surface area with the greatest epithelial cell coverage (i.e. thicker lamellae, longer diffusion distance) and a larger interlamellar cell mass, contrasting with 11 ppt-acclimated fish, which had overall the highest respiratory surface area. The alteration of an array of physiological parameters provides evidence for a compromise between salinity and hypoxia tolerance in killifish acclimated to freshwater.
Collapse
Affiliation(s)
- Marina Giacomin
- Department of Zoology, The University of British Columbia, Vancouver, BC, Canada V6T 1Z4 .,Bamfield Marine Sciences Centre, Bamfield, BC, Canada V0R 1B0
| | - Heather J Bryant
- Department of Zoology, The University of British Columbia, Vancouver, BC, Canada V6T 1Z4
| | - Adalberto L Val
- Laboratory of Ecophysiology and Molecular Evolution, Instituto Nacional de Pesquisas da Amazônia (INPA), Manaus, Amazonas 69080-971, Brazil
| | - Patricia M Schulte
- Department of Zoology, The University of British Columbia, Vancouver, BC, Canada V6T 1Z4
| | - Chris M Wood
- Department of Zoology, The University of British Columbia, Vancouver, BC, Canada V6T 1Z4.,Bamfield Marine Sciences Centre, Bamfield, BC, Canada V0R 1B0.,Department of Biology, McMaster University, Hamilton, ON, Canada L8S 4K1
| |
Collapse
|
5
|
Wood CM, Ruhr IM, Schauer KL, Wang Y, Mager EM, McDonald MD, Stanton B, Grosell M. The osmorespiratory compromise in the euryhaline killifish: water regulation during hypoxia. ACTA ACUST UNITED AC 2019; 222:jeb.204818. [PMID: 31466998 DOI: 10.1242/jeb.204818] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2019] [Accepted: 08/27/2019] [Indexed: 01/15/2023]
Abstract
Freshwater- and seawater-acclimated Fundulus heteroclitus were exposed to acute hypoxia (10% air saturation, 3 h), followed by normoxic recovery (3 h). In both salinities, ventilation increased and heart rate fell in the classic manner, while Ṁ O2 initially declined by ∼50%, with partial restoration by 3 h of hypoxia, and no O2 debt repayment during recovery. Gill paracellular permeability (measured with [14C] PEG-4000) was 1.4-fold higher in seawater, and declined by 50% during hypoxia with post-exposure overshoot to 188%. A similar pattern with smaller changes occurred in freshwater. Drinking rate (also measured with [14C] PEG-4000) was 8-fold higher in seawater fish, but declined by ∼90% during hypoxia in both groups, with post-exposure overshoots to ∼270%. Gill diffusive water flux (measured with 3H2O) was 1.9-fold higher in freshwater fish, and exhibited a ∼35% decrease during hypoxia, which persisted throughout recovery, but was unchanged during hypoxia in seawater fish. Nevertheless, freshwater killifish gained mass while seawater fish lost mass during hypoxia, and these changes were not corrected during normoxic recovery. We conclude that this hypoxia-tolerant teleost beneficially reduces gill water permeability in a salinity-dependent fashion during hypoxia, despite attempting to simultaneously improve Ṁ O2 , but nevertheless incurs a net water balance penalty in both freshwater and seawater.
Collapse
Affiliation(s)
- Chris M Wood
- Department of Marine Biology and Ecology, Rosenstiel School of Marine and Atmospheric Science, University of Miami, Miami, FL 33149, USA .,Department of Zoology, University of British Columbia, Vancouver, BC V6T 1Z4, Canada.,Department of Biology, McMaster University, Hamilton, ON L8S 4K1, Canada
| | - Ilan M Ruhr
- Department of Marine Biology and Ecology, Rosenstiel School of Marine and Atmospheric Science, University of Miami, Miami, FL 33149, USA.,Cardiovascular Sciences, School of Medical Sciences, University of Manchester, Manchester M13 9NT, UK
| | - Kevin L Schauer
- Department of Marine Biology and Ecology, Rosenstiel School of Marine and Atmospheric Science, University of Miami, Miami, FL 33149, USA
| | - Yadong Wang
- Department of Marine Biology and Ecology, Rosenstiel School of Marine and Atmospheric Science, University of Miami, Miami, FL 33149, USA
| | - Edward M Mager
- Department of Marine Biology and Ecology, Rosenstiel School of Marine and Atmospheric Science, University of Miami, Miami, FL 33149, USA.,Department of Biological Sciences, Advanced Environmental Research Institute, University of North Texas, Denton, TX 76203, USA
| | - M Danielle McDonald
- Department of Marine Biology and Ecology, Rosenstiel School of Marine and Atmospheric Science, University of Miami, Miami, FL 33149, USA
| | - Bruce Stanton
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, NH 03755, USA
| | - Martin Grosell
- Department of Marine Biology and Ecology, Rosenstiel School of Marine and Atmospheric Science, University of Miami, Miami, FL 33149, USA
| |
Collapse
|
6
|
Wu NC, Cramp RL, Ohmer MEB, Franklin CE. Epidermal epidemic: unravelling the pathogenesis of chytridiomycosis. ACTA ACUST UNITED AC 2019; 222:jeb.191817. [PMID: 30559300 DOI: 10.1242/jeb.191817] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2018] [Accepted: 12/05/2018] [Indexed: 12/18/2022]
Abstract
Chytridiomycosis, a lethal fungal skin disease of amphibians, fatally disrupts ionic and osmotic homeostasis. Infected amphibians increase their skin shedding rate (sloughing) to slow pathogen growth, but the sloughing process also increases skin permeability. Healthy amphibians increase active ion uptake during sloughing by increasing ion transporter abundance to offset the increased skin permeability. How chytridiomycosis affects the skin function during and between sloughing events remains unknown. Here, we show that non-sloughing frogs with chytridiomycosis have impaired cutaneous sodium uptake, in part because they have fewer sodium transporters in their skin. Interestingly, sloughing was associated with a transient increase in sodium transporter activity and abundance, suggesting that the newly exposed skin layer is initially fully functional until the recolonization of the skin by the fungus again impedes cutaneous function. However, the temporary restoration of skin function during sloughing does not restore ionic homeostasis, and the underlying loss of ion uptake capacity is ultimately detrimental for amphibians with chytridiomycosis.
Collapse
Affiliation(s)
- Nicholas C Wu
- School of Biological Sciences, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Rebecca L Cramp
- School of Biological Sciences, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Michel E B Ohmer
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - Craig E Franklin
- School of Biological Sciences, The University of Queensland, Brisbane, Queensland 4072, Australia
| |
Collapse
|
7
|
Lucu Č, Ziegler A. The effects of hypoxia on active ionic transport processes in the gill epithelium of hyperregulating crab, Carcinus maneas. Comp Biochem Physiol A Mol Integr Physiol 2017. [PMID: 28629793 DOI: 10.1016/j.cbpa.2017.06.011] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Effects of hypoxia on the osmorespiratory functions of the posterior gills of the shore crab Carcinus maenas acclimated to 12ppt seawater (DSW) were studied. Short-circuit current (Isc) across the hemilamella (one epithelium layer supported by cuticle) was substantially reduced under exposure to 1.6, 2.0, or 2.5mg O2/L hypoxic saline (both sides of epithelium) and fully recovered after reoxygenation. Isc was reduced equally in the epithelium exposed to 1.6mg O2/L on both sides and when the apical side was oxygenated and the basolateral side solely exposed to hypoxia. Under 1.6mg O2/L, at the level of maximum inhibition of Isc, conductance was decreased from 40.0mScm-2 to 34.7mScm-2 and fully recovered after reoxygenation. Isc inhibition under hypoxia and reduced 86Rb+ (K+) fluxes across apically located K+ channels were caused preferentially by reversible inhibition of basolaterally located and ouabain sensitive Na+,K+-ATPase mediated electrogenic transport. Reversible inhibition of Isc is discussed as decline in active transport energy supply down regulating metabolic processes and saving energy during oxygen deprivation. In response to a 4day exposure of Carcinus to 2.0mg O2/L, hemolymph Na+ and Cl- concentration decreased, i.e. hyperosmoregulation was weakened. Variations of the oxygen concentration level and exposure time to hypoxia lead to an increase of the surface of mitochondria per epithelium area and might in part compensate for the decrease in oxygen availability under hypoxic conditions.
Collapse
Affiliation(s)
- Čedomil Lucu
- Alfred Wegener- Institute Helmholtz Center for Polar and Marine Research Wadden Sea Station/List/Sylt, Germany; Institute Ruđer Bošković, Center for Marine Research Rovinj, Zagreb, Croatia.
| | - Andreas Ziegler
- Central Facility for Electron Microscopy University of Ulm, A. Einstein Alee 11, 89069 Ulm, Germany
| |
Collapse
|