Osmotic and cationic urine concentrations/blood concentrations ratios in hyporegulating Ucides cordatus

doi:10.1016/0300-9629(85)90926-0

Comparative Biochemistry and Physiology Part A: Physiology

Volume 81, Issue 4, 1985, Pages 895-898

Comparative Biochemi...

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Abstract

1.
1. In crabs exposed to sea-water for 96 hr, the haemolymph sodium, potassium, calcium, magnesium and osmotic concentrations have risen, but to levels below those found in the medium.
2.
2. Blood and urine were isosmotic for all exposure times.
3.
3. Urine sodium concentration was higher than that of blood during the first 24 hr.
4.
4. Urine, potassium and magnesium concentrations were higher than those of blood during every exposure period.
5.
5. Na U/B ratios and K U/B ratios significantly decreased, whereas Mg U/B ratios significantly increased along the sea-water exposure time.
6.
6. The role of the antennal gland is discussed.

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Salt and water balance in selected crabs of Madagascar
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Osmotic and ionic regulation
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Relationship concerning respiratory devices in crabs from different habitats
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Transition from water to land in decapod crustacean
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Premières donnés sur la régulation osmotique et la régulation ionique du crabe terrestre, Cardisoma armatum Herkiots
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There are more references available in the full text version of this article.

Cited by (14)

Osmotic and ionic regulation, and modulation by protein kinases, FXYD2 peptide and ATP of gill (Na<sup>+</sup>, K<sup>+</sup>)-ATPase activity, in the swamp ghost crab Ucides cordatus (Brachyura, Ocypodidae)
2020, Comparative Biochemistry and Physiology Part - B: Biochemistry and Molecular Biology
Citation Excerpt :
Acclimation of U. cordatus to dilute seawater increases (Na+, K+)-ATPase activity by ≈1.5-fold in the posterior gills and by ≈2-fold in the antennal glands (Harris and Santos, 1993b). However, while osmoregulatory ability seems well characterized (Santos and Salomão, 1985a, 1985b), little is known of the biochemical processes underlying ion transport in U. cordatus gills. Here, we evaluate the regulation in vitro of gill (Na+, K+)-ATPase activity of U. cordatus after 10 days acclimation to hypo-, iso- or hyper-osmotic salinities by the endogenous protein kinases PKA, PKC and CaMK, and by an exogenous pig kidney FXYD2 peptide.
We analyzed the modulation by exogenous FXYD2 peptide and by endogenous protein kinases A and C, and Ca²⁺-calmodulin-dependent kinase, of gill (Na⁺, K⁺)-ATPase activity in the semi-terrestrial mangrove crab Ucides cordatus after 10-days acclimation to different salinities. Osmotic and ionic regulatory ability and gill (Na⁺, K⁺)-ATPase activity also were evaluated. (Na⁺, K⁺)-ATPase activity is stimulated by exogenous pig kidney FXYD2 peptide, while phosphorylation by endogenous protein kinases A and C and Ca²⁺/calmodulin-dependent kinase inhibits activity. Stimulation by FXYD2 and inhibition by protein kinase C and Ca²⁺/calmodulin-dependent kinase are salinity-dependent. This is the first demonstration of inhibitory phosphorylation of a crustacean (Na⁺, K⁺)-ATPase by Ca²⁺/calmodulin-dependent kinase. At low salinities, the (Na⁺, K⁺)-ATPase exhibited a single, low affinity ATP-binding site that showed Michaelis-Menten behavior. Above 18‰S, a second, cooperative, high affinity ATP-binding site appeared, corresponding to 10–20% of total (Na⁺, K⁺)-ATPase activity. Hemolymph osmolality was strongly hyper−/hypo-regulated in crabs acclimated at 2 to 35‰S. Cl⁻ was well hyper−/hypo-regulated although Na⁺ much less so, becoming isonatremic at elevated salinity. (Na⁺, K⁺)-ATPase activity was greatest in isosmotic crabs (26‰S), decreasing notably at 35‰S and also diminishing progressively from 18to 2‰S. Hyper-osmoregulation in U. cordatus showed little dependence on gill (Na⁺, K⁺)-ATPase activity, suggesting a role for other ion transporters. These findings reveal that the salinity acclimation response in U. cordatus consists of a suite of enzymatic and osmoregulatory adjustments that maintain its osmotic homeostasis in a challenging, mangrove forest environment.
Calcium transport in gill cells of Ucides cordatus, a mangrove crab living in variable salinity environments
2013, Comparative Biochemistry and Physiology - A Molecular and Integrative Physiology
Citation Excerpt :
However, no study have looked at cellular Ca2 + transport in isolated gill cells of mangrove crabs (see Sá et al., 2009, 2010). U. cordatus is a typical Brazilian mangrove crab and can osmoregulate at salinities in the range of 2–33 ppt (Santos and Salomão, 1985; Martinez et al., 1999). At these salinities these crabs are able to regulate hemolymph Na tightly, suggesting a strong homeostatic mechanism during exposure to different salinities (Martinez et al., 1998).
Crustaceans show discontinuous growth and have been used as a model system for studying cellular mechanisms of calcium transport, which is the main mineral found in their exoskeleton. Ucides cordatus, a mangrove crab, is naturally exposed to fluctuations in calcium and salinity. To study calcium transport in this species during isosmotic conditions, dissociated gill cells were marked with fluo-3 and intracellular Ca^2 + change was followed by adding extracellular Ca^2 + as CaCl₂ (0, 0.1, 0.25, 0.50, 1.0 and 5 mM), together with different inhibitors. For control gill cells, Ca^2 + transport followed Michaelis–Menten kinetics with V_max = 0.137 ± 0.001 ∆Ca^2 +i (μM × 22.10⁴ cells^− 1 × 180 s^− 1; N = 4; r² = 0.99); K_m = 0.989 ± 0.027 mM. The use of different inhibitors for gill cells showed that amiloride (Na⁺/Ca^2 + exchange inhibitor) inhibited 80% of Ca^2 + transport in gill cells (V_max). KB-R, an inhibitor of Ca influx in vertebrates, similarly caused a decrease in Ca^2 + transport and verapamil (Ca^2 + channel inhibitor) had no effect on Ca^2 + transport, while nifedipine (another Ca^2 + channel inhibitor) caused a 20% decrease in Ca^2 + affinity compared to control values. Ouabain, on the other hand, caused no change in Ca^2 + transport, while vanadate increased the concentration of intracellular calcium through inhibition of Ca^2 + efflux probably through the plasma membrane Ca^2 +-ATPase. Results show that transport kinetics for Ca^2 + in these crabs under isosmotic conditions is lower compared to a hyper-regulator freshwater crab Dilocarcinus pagei studied earlier using fluorescent Ca^2 + probes. These kinds of studies will help understanding the comparative mechanisms underlying the evolution of Ca transport in crabs living in different environments.
A structure-function analysis of ion transport in crustacean gills and excretory organs
2008, Comparative Biochemistry and Physiology - A Molecular and Integrative Physiology
Citation Excerpt :
Riegel's early, groundbreaking, micropuncture studies (e.g., Riegel, 1963, 1965, 1966a,b, 1968) analyzed decapod antennal gland function, establishing the essential ion transport characteristics of each antennal gland segment in the freshwater crayfish. Investigations on urine composition and urine/hemolymph ratios for osmolality, inulin and specific ions have revealed the ability of various species to produce dilute urine at low salinities or in freshwater (Robertson, 1960; Schmidt-Nielsen et al., 1968; Mantel and Farmer, 1983; Santos and Salomão, 1985; Schoffeniels and Dandrifosse, 1994). The principal enzyme driving active, epithelial transport, the Na+/K+-ATPase, has been localized to specific organ segments, and its activity measured in several species, although to a far lesser extent than in gills (e.g., Peterson and Loizzi, 1974; Sarver et al., 1994; Khodabandeh et al., 2005b).
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⁻, Ca²⁺ and NH₄⁺ 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.
Drinking and osmoregulation in the mangrove crab Ucides cordatus following exposure to benzene
2002, Comparative Biochemistry and Physiology - A Molecular and Integrative Physiology
In benzene-exposed Ucides cordatus acclimated for 96 h to 9 and 34‰ SW, haemolymph, urine and gastric juice are isosmotic with each other, but differ significantly in osmolality from external media. In both salinities, under benzene action, urine K⁺ excretion and calcium absorption are increased significantly, whereas Na⁺ absorption and Mg²⁺ excretion show U/B ratios similar to control values. In 9‰ SW, some ionic exchanges via benzene-exposed gills are possibly hastened. Benzene exposure decreases significantly branchial chamber water osmolality, [Na⁺] and [K⁺], whereas [Ca²⁺] and [Mg²⁺] are unaffected. However, faster medium exchange presumably occurs in 34‰ SW, both crab groups show branchial chamber water osmotic and ionic concentrations similar to surrounding medium. Benzene exposure unaffected gastric juice composition. In both media, [Ca²⁺] and [Mg²] accumulate several times higher than surrounding media, and [Na⁺] and [K⁺] are significantly hypo-ionic to haemolymph. Na⁺ and K⁺ G/H ratios are lower in crabs acclimated to 34‰ SW than in crabs acclimated to 9‰ SW. Drinking rates are enhanced by benzene exposure and are higher at 34‰ SW than in seawater isosmotic with the haemolymph (26‰ SW). Benzene exposure affects significantly osmoregulatory capability, slowing haemolymph dilution after transfer to clean 9‰ SW. Lower haemolymph dilution rate accounts for higher osmolality, but 48 h after transfer there is no recovery like in control crabs. Haemolymph transfusion experiments suggest an interaction among effects of benzene and hormonal factors, possibly on water influx.
A morphological study on posterior gills of the mangrove crab Ucides cordatus
1999, Tissue and Cell
Morphological and histological studies on posterior gills of the mangrove crab Ucides cordatus showed that the 5th gill (of 7) has a larger surface area and a greater number of lamellae compared to the 6th gill. Regular separation of gill lamellae, important when the gill is in air, is maintained by enlargements of the marginal canals. Conical, spine-like structures along the efferent vessel of both 5th and 6th gills were also observed. In addition, pillar cells, a discontinuous lamellar septum and a hypobranchial artery were observed. The presence of valve-like structures near the efferent vessel was also indicated. These structures, together with the pillar cells, may have a role in directing the hemolymph flow towards certain gills during particular physiological states. Localization of osmoregulatory epithelia in the lamellae of both gills was inferred from dimethylaminostyrylethylpyridiniumiodine staining. Apparently gills 5 and 6 have osmoregulatory epithelial cell patches of similar area, corresponding to 43% and 38% of the total lamellae area, respectively. However, their localization is quite different. Gill number 5 osmoregulatory patches seem to be restricted to the afferent region of the lamella whereas in gill number 6, they are more dispersed over the entire lamella. These differences may be related to the particular functional characteristics of these gills.
Transepithelial potential differences and sodium fluxes in isolated perfused gills of the mangrove crab Ucides cordatus
1998, Comparative Biochemistry and Physiology - A Molecular and Integrative Physiology
Marked differences in transepithelial potential difference (TEP) and unidirectional sodium fluxes were observed in isolated, perfused posterior gills 5 and 6 of the hyper–hyporegulating crab Ucides cordatus. Gills were perfused with a saline which closely matched the composition of the crab's haemolymph, and bathed with 9, 17, 26 and 34‰ seawater (SW). In 26‰ SW, TEPs were small and similar in magnitude and sign for both gills, but in all other salinities TEPs were very different, exhibiting opposite polarities and different responses to the changes in external salinity. Calculated relative ionic permeabilities, P_Na:P_Cl, showed that gills 5 were more permeable to sodium than gills 6, while the latter were chloride permeable. In gills 5 the TEP can be regarded as a diffusion potential. This is not the case in gill 6 where ion extrusion probably takes place. Influx rates in gill 5 were larger than efflux rates in all salinities and ranged from 726.93±103.52 to 1111.47±135.55 μM Na⁺ g⁻¹ h⁻¹. Sodium efflux varied from 337.49±56.42 to 689.03±108.87 μM Na⁺ g⁻¹ h⁻¹. In gill 6 influx rates were orders of magnitude smaller (3.67±0.25 to 8.45±0.79 μM Na⁺ g⁻¹ h⁻¹), while efflux rates varied from 87.24±20.25 to 223.27±19.38 μM Na⁺ g⁻¹ h⁻¹. Flux-ratio analysis showed active uptake of Na⁺ in gill 5 and active extrusion in gills 6, suggesting functional differences in adjacent gills of this hyper–hyporegulating crab.

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Comparative Biochemistry and Physiology Part A: Physiology

Abstract

References (14)

Salt and water balance in selected crabs of Madagascar

Comp. Biochem. Physiol.

Salt and water balance in the West African fresh water/land crab Sudanonautes africanus africanus and the effects of desiccation

Comp. Biochem. Physiol.

Osmotic and ionic regulation

Relationship concerning respiratory devices in crabs from different habitats

Comp. Biochem. Physiol.

Transition from water to land in decapod crustacean

Am. Zool.

From sea to tree: saga of a land crab

Am. Zool.

Premières donnés sur la régulation osmotique et la régulation ionique du crabe terrestre, Cardisoma armatum Herkiots

Cah. Biol. mar.

Cited by (14)

Osmotic and ionic regulation, and modulation by protein kinases, FXYD2 peptide and ATP of gill (Na<sup>+</sup>, K<sup>+</sup>)-ATPase activity, in the swamp ghost crab Ucides cordatus (Brachyura, Ocypodidae)

Calcium transport in gill cells of Ucides cordatus, a mangrove crab living in variable salinity environments

A structure-function analysis of ion transport in crustacean gills and excretory organs

Drinking and osmoregulation in the mangrove crab Ucides cordatus following exposure to benzene

A morphological study on posterior gills of the mangrove crab Ucides cordatus

Transepithelial potential differences and sodium fluxes in isolated perfused gills of the mangrove crab Ucides cordatus

General paperOsmotic and cationic urine concentrations/blood concentrations ratios in hyporegulating Ucides cordatus

Abstract

Comp. Biochem. Physiol.

Comp. Biochem. Physiol.

Comp. Biochem. Physiol.

Transition from water to land in decapod crustacean

Am. Zool.

From sea to tree: saga of a land crab

Am. Zool.

Premières donnés sur la régulation osmotique et la régulation ionique du crabe terrestre, Cardisoma armatum Herkiots

Cah. Biol. mar.

General paper
Osmotic and cationic urine concentrations/blood concentrations ratios in hyporegulating Ucides cordatus