Active excretion of ammonia across the gills of the shore crab Carcinus maenas and its relation to osmoregulatory ion uptake

Weihrauch, Dirk; Becker, W.; Postel, U.; Riestenpatt, S.; Siebers, D.

doi:10.1007/s003600050156

Cited by 88 publications

(76 citation statements)

References 31 publications

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“…Furthermore, application of Ba 2+ in split gills of the Chinese mitten crab, Eriocheir sinensis, resulted in a complex di-phasic response of the short-circuit current I SC (Onken et al, 1991), also indicating the participation of more than one kind of K + channel. In addition to their role in osmoregulation, basolateral K + channels also participate in branchial ammonia excretion in C. maenas, with NH 4 + substituting for K + because of its similar size and charge (Lignon, 1987;Skou, 1960;Weihrauch et al, 1998). Apical application of Cs + , however, did not affect branchial ammonia excretion in this species (Weihrauch et al, 1998).…”

Section: +mentioning

confidence: 97%

The role of an ancestral hyperpolarization activated cyclic nucleotide-gated K+-channel in branchial acid-base regulation in the green crab,Carcinus maenas(L.)

Fehsenfeld

Weihrauch

2016

Journal of Experimental Biology

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Numerous electrophysiological studies on branchial K + transport in brachyuran crabs have established an important role for potassium channels in osmoregulatory ion uptake and ammonia excretion in the gill epithelium of decapod crustaceans. However, hardly anything is known of the actual nature of these channels in crustaceans. In the present study, the identification of a hyperpolarization-activated cyclic nucleotide-gated potassium channel (HCN) in the transcriptome of the green crab Carcinus maenas and subsequent performance of quantitative real-time PCR revealed the ubiquitous expression of this channel in this species. Even though mRNA expression levels in the cerebral ganglion were found to be approximately 10 times higher compared with all other tissues, posterior gills still expressed significant levels of HCN, indicating an important role for this transporter in branchial ion regulation. The relatively unspecific K + -channel inhibitor Ba 2+ , as well as the HCN-specific blocker ZD7288, as applied in gill perfusion experiments and electrophysiological studies employing the split gill lamellae revealed the presence of at least two different K + /NH 4 + -transporting structures in the branchial epithelium of C. maenas. Furthermore, HCN mRNA levels in posterior gill 7 decreased significantly in response to the respiratory or metabolic acidosis that was induced by acclimation of green crabs to high environmental P CO2 and ammonia, respectively. Consequently, the present study provides first evidence that HCNpromoted NH 4 + epithelial transport is involved in both branchial acidbase and ammonia regulation in an invertebrate.

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Section: +mentioning

confidence: 97%

The role of an ancestral hyperpolarization activated cyclic nucleotide-gated K+-channel in branchial acid-base regulation in the green crab,Carcinus maenas(L.)

Fehsenfeld

Weihrauch

2016

Journal of Experimental Biology

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“…In these experiments, 0.5% DMSO was also added to the control solutions. Inhibitor concentrations were chosen to be within the range applied in comparable studies on other invertebrates (Weihrauch et al, 1998(Weihrauch et al, , 2012b(Weihrauch et al, , 2004a. Comparatively high doses were needed for acetazolamide and colchicine, probably because of the need to penetrate the apical membrane of the hypodermal syncytium.…”

Section: Nitrogen Excretion Experiments Inhibitor and Ph Experimentsmentioning

confidence: 99%

“…Determination of ammonia and urea in excretion experiments using an NH 3 -selective electrode Ammonia samples from excretion experiments were analyzed using a gassensitive NH 3 electrode (Thermo Orion, Beverly, MA, USA) connected to a digital pH meter as described in detail by Weihrauch et al (1998) For the parallel determination of ammonia (A) and urea (U), samples were split in half, S A and S U , as also described by Cruz et al (2013). Sample A was analyzed for background ammonia concentration, whereas sample S U was treated with urease type III, employed at a final concentration of 10 units ml −1 (Sigma, St Louis, MO, USA) for 30 min at room temperature to convert all urea into ammonia and CO 2 .…”

Section: Body Ammonia Concentrationmentioning

confidence: 99%

“…For the basolateral localized Na + /K + -ATPase, it was shown in 1960 by Jens Skou that this enzyme does accept NH 4 + as a substrate by replacing K + ions (Skou, 1960) and thereby is capable of actively pumping NH 4 + from the body fluids into the respective ammonia-transporting epithelial cell. The direct participation of this pump in the ammonia transport mechanism has now been identified for numerous systems, including those in gills of crustaceans (Furriel et al, 2004;Masui et al, 2002;Weihrauch et al, 1998;Weihrauch et al, 1999) and fish (Mallery, 1983;Nawata et al, 2010a;Wood et al, 2013), frog skin (Cruz et al, 2013), mammalian kidney (Garvin et al, 1985;Wall and Koger, 1994) and intestine (Worrell et al, 2008). The second pump often, if not always, involved in the ammonia transport processes is the V-ATPase.…”

Section: Introductionmentioning

confidence: 99%

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Ammonia excretion inCaenorhabditis elegans: mechanism and evidence of ammonia transport of the Rhesus protein CeRhr-1

Adlimoghaddam

Boeckstaens

Marini

et al. 2015

Journal of Experimental Biology

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The soil-dwelling nematode Caenorhabditis elegans is a bacteriovorous animal, excreting the vast majority of its nitrogenous waste as ammonia (25.3±1.2 µmol gFW −1 day ). Although these roundworms have been used for decades as genetic model systems, very little is known about their strategy to eliminate the toxic waste product ammonia from their bodies into the environment. The current study provides evidence that ammonia is at least partially excreted via the hypodermis. Starvation reduced the ammonia excretion rates by more than half, whereas mRNA expression levels of the Rhesus protein CeRhr-2, V-type H + -ATPase (subunit A) and Na + /K + -ATPase (α-subunit) decreased correspondingly. Moreover, ammonia excretion rates were enhanced in media buffered to pH 5 and decreased at pH 9.5. Inhibitor experiments, combined with enzyme activity measurements and mRNA expression analyses, further suggested that the excretion mechanism involves the participation of the V-type H +

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“…The anterior gills are the main sites for gas exchange whereas the posterior ones participate mainly in salt transporting processes (Siebers et al 1982 ;Gilles & Pe! queux, 1986 ;Towle, 1990 ;Taylor & Taylor, 1992 ;Weihrauch et al 1998). The epithelium lining posterior gills characteristically shows thick cells with extensive interdigitations of the plasma membranes closely related to mitochondria (Copeland, 1968).…”

Section: mentioning

confidence: 99%

The morphometric changes in the gills of the estuarine crab Chasmagnathus granulatus under hyper‐ and hyporegulation conditions are not caused by proliferation of specialised cells

et al. 2000

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Chasmagnathus granulatus is a hyper-hyporegulating crab that inhabits changing habitats of salinity in Brazil, Uruguay and Argentina. Since the gills are the main sites for active ion transport in crabs, the adaptive changes in the gill epithelium occurring under different conditions of salinity were studied by means of morphological and morphometric analysis, and immunohistochemical identification of cell proliferation (BrdU technique). In anterior (1-3) gills the epithelium thickness from crabs acclimatised to 12, 34 and 44 g\l ranged from 1n27 to 2n46 µm, with no significant change during acclimatisation, thus denoting a respiratory function. Medial (4-5) gill epithelium was slightly thicker in extreme salinities, but these differences were not statistically significant. In contrast, epithelial thickness of the posterior (6-8) gills increased significantly up to 8n10 µm (dorsal zone of gill 8) both in hyper-and hyposaline media compared with seawater. The dark areas measured in gill 8 treated with AgNO $ revealed putative ion transporting tissue, especially at 12 and 44 g\l, corresponding to the zones of higher epithelial thickness. Hence these areas seem to participate both in hyper-and hyporegulation. Proliferating cells labelled with BrdU almost never occurred in the gills\salinity combinations studied during the initial 48 h of transfer from seawater to hyperconcentrated or diluted media, thus suggesting an increase in cell size rather than cell proliferation.

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Active excretion of ammonia across the gills of the shore crab Carcinus maenas and its relation to osmoregulatory ion uptake

Cited by 88 publications

References 31 publications

The role of an ancestral hyperpolarization activated cyclic nucleotide-gated K+-channel in branchial acid-base regulation in the green crab,Carcinus maenas(L.)

The role of an ancestral hyperpolarization activated cyclic nucleotide-gated K+-channel in branchial acid-base regulation in the green crab,Carcinus maenas(L.)

Ammonia excretion inCaenorhabditis elegans: mechanism and evidence of ammonia transport of the Rhesus protein CeRhr-1

The morphometric changes in the gills of the estuarine crab Chasmagnathus granulatus under hyper‐ and hyporegulation conditions are not caused by proliferation of specialised cells

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