Control of Calcium Balance in Fish

Guerreiro, Pedro M.; Fuentes, Juan

doi:10.1201/b10994-16

Cited by 9 publications

(19 citation statements)

References 236 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The intracellular Ca 2+ concentration of the chloride cells is very low, and consequently apical uptake is diffusional by a Ca 2+ channel even from soft water (Evans et al, 2005). The exit of Ca 2+ across the basolateral membrane is active, involving the Ca 2+ -ATPase and the Na + /Ca 2+ exchanger (Guerreiro & Fuentes, 2007). Tamoatás transferred to chambers with ion-poor black water or well water presented net Ca 2+ efflux in the first 2 h of experiment.…”

Section: Discussionmentioning

confidence: 98%

Calcium fluxes in Hoplosternum littorale (tamoatá) exposed to different types of Amazonian waters

et al. 2009

View full text Add to dashboard Cite

Fishes that live in the Amazonian environment may be exposed to several kinds of waters: ''black waters'', containing high dissolved organic carbon and acidic pH, ''white waters'', with ten fold higher Ca 2+ concentrations than black waters and neutral pH, and ''clear waters'', with two fold higher Ca 2+ concentrations than black waters and also neutral pH. Therefore, the aim of the present study was to analyze Ca 2+ fluxes in the facultative air-breather Hoplosternum littorale (tamoatá) exposed to different Amazonian waters. Fishes were acclimated in well water (similar to clear water) and later placed in individual chambers for Ca 2+ fluxes measurements. After 4 h, water from the chambers was replaced by a different type of water. Transfer of tamoatás to ion-poor black or acidic black water resulted in net Ca 2+ loss only in the first 2 h of experiment. However, transfer from black or acidic black water to white water led to only net Ca 2+ influxes. The results obtained allowed us to conclude that transfer of tamoatás to ion-poor waters (black and acidic black water) led to transient net Ca 2+ loss, while the amount of Ca 2+ in the ion-rich white water seems adequate to prevent Ca 2+ loss after transfer. Therefore, transfer of tamoatás between these Amazonian waters does not seem to result in serious Ca 2+ disturbance.Os peixes que vivem na Amazônia são expostos a vários tipos de água: águas pretas, contendo grande quantidade de carbono orgânico dissolvido, águas brancas, com concentração de Ca 2+ dez vezes maior que as águas pretas e pH neutro, e águas claras, com concentração de Ca 2+ duas vezes maior que as águas pretas e pH também neutro. Dessa forma, o objetivo deste trabalho foi analisar o fluxo de Ca 2+ no peixe de respiração aérea facultativa Hoplosternum littorale (tamoatá) exposto a diferentes tipos de águas amazônicas. Os peixes foram aclimatados em água de poço artesiano (semelhante à água clara) e depois colocados individualmente em câmaras para medir o fluxo de Ca 2+ . Após 4 h, a água das câmaras foi trocada por um tipo diferente de água. A transferência do tamoatá das águas pobres em íons água preta e preta ácida ou da água branca, rica em íons, para as águas preta e preta ácida, pobres em íons, resulta em uma perda de Ca 2+ apenas nas duas primeiras horas de experimento. Entretanto, a transferência da água preta e preta ácida, para a água branca resulta em um influxo de Ca 2+ . Os resultados obtidos nos permitem concluir que a transferência do tamoatá para as águas preta e preta ácida, pobres em íons, leva a uma temporária perda de Ca 2+ , e a quantidade de Ca 2+ na água branca, rica em íons, é adequada para prevenir sua perda após a transferência. Sendo assim, a transferência do tamoatá entre as águas estudadas não resulta em sérios distúrbios no Ca 2+ .

show abstract

Section: Discussionmentioning

confidence: 98%

Calcium fluxes in Hoplosternum littorale (tamoatá) exposed to different types of Amazonian waters

et al. 2009

View full text Add to dashboard Cite

show abstract

“…The in vitro model used in the present study strongly supports a role for PTHrP in the rapid renal regulation of plasma Ca 2ϩ and P i in fishes, substantiating our previous observations that a functional parathyroid-like system evolved before the colonization of land by vertebrates. Such a system, together with the antihypercalcemic peptide STC and calcitriol, equipped fish with mechanisms to thrive in a wide range of Ca 2ϩ concentrations (25) and still keep balance with the low environmental P i . Clearly, additional studies on the interaction between such systems are justified, and further information should be gathered from in vivo experiments under different Ca 2ϩ and P i conditions to determine actual excretion levels and hormone secretion and clearance rates.…”

Section: Perspectivesmentioning

confidence: 99%

“…Teleosts, either freshwater or marine, face a constant Ca 2ϩ influx from the environment, and compensation includes active excretion by several routes, including the urine (6,25). P i , however, is normally scarce in the aquatic environment, the only adequate source being the food, and therefore fish must balance the sporadic dietary intake with metabolic utilization and renal excretion lest Ca 2ϩ activity is perturbed (33,41).…”

mentioning

confidence: 99%

“…Fish, like most nonmammalian vertebrates (5), are capable of net renal P i secretion, a phenomenon apparently regulated by protein kinase C (PKC)-mediated-pathways (41). However, the primary messenger stimulating renal P i secretion in the fishes is unknown, and the roles of other classic hormones such as calcitonin and vitamin D in fish kidney Ca 2ϩ and P i physiology are unclear (1,21,25,26,33,36).…”

mentioning

confidence: 99%

See 1 more Smart Citation

Piscine PTHrP regulation of calcium and phosphate transport in winter flounder renal proximal tubule primary cultures

Guerreiro

Canário

Power

et al. 2010

American Journal of Physiology-Regulatory, Integrative and Comp

View full text Add to dashboard Cite

Multiple factors control calcium (Ca(2+)) and inorganic phosphate (P(i)) transport in the fish nephron, and the recently discovered members of the piscine parathyroid hormone-like protein family are likely participants in such regulatory mechanisms. The effects of an NH(2)-terminal peptide (amino acids 1-34) of Takifugu rubripes parathyroid hormone-related protein, (1-34)PTHrP, on Ca(2+) and P(i) transport were investigated in winter flounder (Pseudopleuronectes americanus) proximal tubule cells in primary culture (fPTCs). RT-PCR performed on RNA extracted from fPTCs and from intact kidney tissue indicated that expression of PTHrP and types 1 and 3 PTH/PTHrP receptors occurred both in vivo and in vitro and that circulating levels of PTHrP measured by specific radioimmunoassay averaged 2.5 +/- 0.13 ng/ml. fPTC monolayers were mounted in Ussing chambers, and under neutral electrochemical conditions, addition of 10 nM (1-34)PTHrP to the basolateral side induced a slight increase in Ca(2+) transport rate from luminal to peritubular side, significantly stimulating net Ca(2+) reabsorption. (1-34)PTHrP also significantly increased the P(i) secretory flux, and slightly reduced P(i) reabsorption, evoking a significant increase in P(i) net secretion. This stimulatory effect was partially inhibited by bisindolylmaleimide, an inhibitor of protein kinase C. Incubation of ex vivo flounder renal tubules with (1-34)PTHrP resulted in apparent reduction of Na(+)-P(i) cotransporter type II (NaP(i)-II) protein in tubule membranes. PTHrP seems therefore to participate in the modulation of Ca(2+) and P(i) homeostasis by fish kidney.

show abstract

“…The gill, together with the kidney, also appears to play a role in Ca 2+ excretion but little is known about this process [3,8]. Branchial Ca 2+ uptake appears to occur mainly through specialized mitochondrion-rich cells (MR cells) or "chloride cells" following a 3-step process similar to that proposed for Ca 2+ reabsorption in the mammalian kidney: passive entry of Ca 2+ through apical epithelial Ca 2+ channels (e.g.…”

Section: Introductionmentioning

confidence: 99%

Gill transcriptome response to changes in environmental calcium in the green spotted puffer fish

et al. 2010

View full text Add to dashboard Cite

BackgroundCalcium ion is tightly regulated in body fluids and for euryhaline fish, which are exposed to rapid changes in environmental [Ca2+], homeostasis is especially challenging. The gill is the main organ of active calcium uptake and therefore plays a crucial role in the maintenance of calcium ion homeostasis. To study the molecular basis of the short-term responses to changing calcium availability, the whole gill transcriptome obtained by Super Serial Analysis of Gene Expression (SuperSAGE) of the euryhaline teleost green spotted puffer fish, Tetraodon nigroviridis, exposed to water with altered [Ca2+] was analysed.ResultsTransfer of T. nigroviridis from 10 ppt water salinity containing 2.9 mM Ca2+ to high (10 mM Ca2+ ) and low (0.01 mM Ca2+) calcium water of similar salinity for 2-12 h resulted in 1,339 differentially expressed SuperSAGE tags (26-bp transcript identifiers) in gills. Of these 869 tags (65%) were mapped to T. nigroviridis cDNAs or genomic DNA and 497 (57%) were assigned to known proteins. Thirteen percent of the genes matched multiple tags indicating alternative RNA transcripts. The main enriched gene ontology groups belong to Ca2+ signaling/homeostasis but also muscle contraction, cytoskeleton, energy production/homeostasis and tissue remodeling. K-means clustering identified co-expressed transcripts with distinct patterns in response to water [Ca2+] and exposure time.ConclusionsThe generated transcript expression patterns provide a framework of novel water calcium-responsive genes in the gill during the initial response after transfer to different [Ca2+]. This molecular response entails initial perception of alterations, activation of signaling networks and effectors and suggests active remodeling of cytoskeletal proteins during the initial acclimation process. Genes related to energy production and energy homeostasis are also up-regulated, probably reflecting the increased energetic needs of the acclimation response. This study is the first genome-wide transcriptome analysis of fish gills and is an important resource for future research on the short-term mechanisms involved in the gill acclimation responses to environmental Ca2+ changes and osmoregulation.

show abstract

Control of Calcium Balance in Fish

Cited by 9 publications

References 236 publications

Calcium fluxes in Hoplosternum littorale (tamoatá) exposed to different types of Amazonian waters

Calcium fluxes in Hoplosternum littorale (tamoatá) exposed to different types of Amazonian waters

Piscine PTHrP regulation of calcium and phosphate transport in winter flounder renal proximal tubule primary cultures

Gill transcriptome response to changes in environmental calcium in the green spotted puffer fish

Contact Info

Product

Resources

About