The Excretion of Magnesium by Carcinus Maenas

1969 ◽  
Vol 51 (3) ◽  
pp. 575-589
Author(s):  
A. P. M. LOCKWOOD ◽  
J. A. RIEGEL
Keyword(s):  
Sea Water ◽  
Carcinus Maenas ◽  
Inulin Clearance ◽  
Secretory Process ◽  
A Value ◽  
Sodium Calcium ◽  
Clearance Studies ◽  
Calcium And Magnesium

1. Measurements have been made of the concentrations of sodium, calcium and magnesium in the blood and urine of Carcinus maenas after transfer to 50 or 150% sea water. Inulin clearance studies were also made. 2. Magnesium is concentrated in the urine by a secretory process when the crabs are in 100% sea water or 150% sea water. There is evidence that the rate of secretion declines when the crabs are in 50% sea water or in 100% magnesium-free sea water. 3. There is no evidence for active withdrawal of magnesium from the urine. When the blood is depleted of this ion the U/B for magnesium drops to a value similar to the U/B for inulin. 4. The clearance of inulin is faster when Carcinus is in 150% sea water than when it is in 100% sea water, and it is calculated that the animal excretes magnesium at a faster rate than it does in 50% sea water. 5. The excretion of magnesium by Carcinus and Pachygrapsus is compared, and it is shown that magnesium is conserved more effectively in dilute media by Carcinus than by Pachygrapsus. This probably reflects differences in the ecology of the two species.

Effect of chlorothiazide on renal calcium and magnesium handling in the hamster

1982 ◽  
Vol 60 (9) ◽  
pp. 1160-1165 ◽  
Author(s):  
Norman L. M. Wong ◽  
Gary A. Quamme ◽  
John H. Dirks
Keyword(s):  
Distal Tubule ◽  
Sodium Concentration ◽  
Urinary Calcium ◽  
Sodium Reabsorption ◽  
Calcium Excretion ◽  
Acute Administration ◽  
Sodium Calcium ◽  
Clearance Studies ◽  
Calcium And Magnesium ◽  
Distal Delivery

Recollection micropuncture and clearance studies were performed on 21 thyroparathyroidcetomized hamsters to characterize the effect of chlorothiazide on tubular sodium, calcium, and magnesium transport. Acute administration of chlorothiazide resulted in a marked natriuresis while urinary calcium excretion fell and magnesium remained unchanged. The fraction of sodium, calcium, and magnesium remaining at the late proximal tubule increased modestly from 65 ± 4 to 75 ± 3, 68 ± 3 to 75 ± 4, and 78 ± 4 to 85 ± 2%, respectively. Distal tubular fluid to ultrafilterable plasma (TF/UF) sodium concentration rose from 0.24 ± 0.03 to 0.44 ± 0.04 whereas distal TF/UFCa concentration fell from 0.58 ± 0.05 to 0.38 ± 0.06. The fraction of sodium remaining at the distal tubule rose from 4.0 ± 1.4 to 10.0 ± 1.4% while that of calcium decreased from 10.2 ± 1.1 to 7.6 ± 1.2% following administration of chlorothiazide. No change was observed in distal delivery of magnesium. Thus chlorothiazide acted in the distal tubule to decrease sodium reabsorption, enhance calcium transport, and had little effect on distal magnesium reabsorption. These data are consistent with the distal tubular action of chlorothiazide which is independent of parathyroid hormone.

scholarly journals The accumulation of radioactive caesium in crabs

1961 ◽  
Vol 41 (3) ◽  
pp. 551-575 ◽  
Author(s):  
G. W. Bryan
Keyword(s):  
Body Surface ◽  
Natural Environment ◽  
Sea Water ◽  
Carcinus Maenas ◽  
The Body ◽  
Limiting Factor ◽  
A Value ◽  
Cancer Pagurus ◽  
The Relationship ◽  
Accuracy Rates

SUMMARYThe accumulation of 134Cs and 42K from artificial sea water has been followed in crabs of the following species, viz. Carcinus maenas, Portunus puber, P. depurator, Polybius henslowi, Cancer pagurus and Corystes. cassivelaunm. In all cases 134Cs is taken up far more slowly than 42K but at equilibrium a higher concentration factor is attained by 134Cs. In Carcinus a value of about 8 is found for 134Cs and about 4 for 42K. Uptake of 134Cs in Carcinus is not affected by feeding on inactive food over a period of 1000 h. The relationship between the rates of uptake of the two isotopes is not the same in the different species and it is concluded that it would not be possible to predict with any accuracy rates of uptake for 134Cs in other species of crabs from the results of short 42K experiments.Uptake of 134Cs was followed in the blood and tissues of Carcinus and Cancer, and muscle is the principal limiting factor in the attainment of equilibrium by whole animals. Uptake of 42K by tissues has also been followed and in all species nearly all the inactive K appears to be readily exchangeable. At equilibrium in all species plasma/sea water and tissue/plasma 134Cs ratios nearly always exceed those for inactive K. The tissue/plasma 134Cs ratios in Carcinus are about twice those for K and the significance of this has been discussed.Loss of both isotopes in whole Carcinus is a slower process than uptake.Isotope accumulation takes place mainly across the body surface in unfed animals, but uptake of 134Cs from food is very rapid and complete and would considerably enhance the attainment of equilibrium in a natural environment.Selective excretion of 134Cs relative to K has been found in Carcinus, Cancer and Portunus puber.

The Regulation of Calcium and Magnesium in the Brackish Water Polychaete Nereis Diversicolor O.F.M

1970 ◽  
Vol 53 (2) ◽  
pp. 425-443
Author(s):  
C. R. FLETCHER
Keyword(s):  
Brackish Water ◽  
Calcium Concentration ◽  
Sea Water ◽  
Calcium Influx ◽  
Coelomic Fluid ◽  
Nereis Diversicolor ◽  
Active Uptake ◽  
Calcium And Magnesium ◽  
Electrochemical Potentials

1. Nereis diversicolor tolerates changes in the concentration of calcium and magnesium in its coelomic fluid proportional to the concentrations in the medium between chlorosities of 100-1000 mM/kg of water. 2. In lower salinities both ions are maintained relatively constant providing that the ratios of these ions to chloride in the medium are similar to the ratios in sea water. 3. The ratio of the concentration of calcium in the coelomic fluid to the concentration in the medium is a function of the salinity of the medium but not of the calcium concentration. 4. Both calcium and magnesium are at lower electrochemical potentials in the coelomic fluid than in the medium, indicating that it is not necessary to invoke active uptake. 5. The rate of calcium influx is substantial. 6. In salinities below to mM of chloride/kg of water the urine must contain less calcium than the coelomic fluid. 7. The significance of these results is discussed.

Urinary Bladder Volume and the Reabsorption of Water from the Urine of Crabs

1974 ◽  
Vol 60 (1) ◽  
pp. 167-181
Author(s):  
J. A. RIEGEL ◽  
A. P. M. LOCKWOOD ◽  
J. R. W. NORFOLK ◽  
N. C. BULLEID ◽  
P. A. TAYLOR
Keyword(s):  
Body Weight ◽  
Urinary Bladder ◽  
Blood Volume ◽  
Ethacrynic Acid ◽  
Sea Water ◽  
Carcinus Maenas ◽  
Bladder Volume ◽  
Active Secretion ◽  
51Cr Edta

1. Measurements have been made to determine the blood volume, bladder volume, clearance of 131I-sodium diatrizoate and U/H for diatrizoate in the crabs Carcinus maenas and Macropipus (Portunus) depurator. 2. Observed values of clearance blood volume and bladder volume in the two species at 18 °C were: Clearance (as % blood volume per day), Macropipus 56.1±14.5; Carcinus 27.1±5.8; Blood volume (as % body weight), Macropipus 21.0±4.0; Carcinus 19.2±3.0; Bladder volume (as % blood volume), Macropipus 12.1 ±5.0; Carcinus 11.0±8.0. 3. It is shown that the measured U/H differs from that to be expected if no reabsorption of water or secretion of diatrizoate occurs. 4. 14C-inulin and 51Cr-EDTA are excreted in an essentially similar manner to 131I-diatrizoate by Carcinus, implying that any active secretion of diatrizoate must be small in magnitude. 5. Injections of ethacrynic acid decrease the U/H ratio for diatrizoate relative to that in control Carcinus injected with sea water. In some Carcinus the concentration of diatrizoate in the urine comes to exceed that initially present in the blood. Both these points are taken, with 3, as support for the conclusion that water can be withdrawn from the primary urine of Carcinus.

scholarly journals Assessment of the physicochemical variables of a subtropical reservoir in the northwest of Argentina

2014 ◽  
Vol 26 (4) ◽  
pp. 367-380 ◽  
Author(s):  
Beatriz Concepción Tracanna ◽  
Silvia Nelly Martínez De Marco ◽  
María de los Ángeles Taboada ◽  
Virginia Mirande ◽  
María de Lourdes Gultemirian ◽  
...  
Keyword(s):  
Dissolved Oxygen ◽  
Physicochemical Parameters ◽  
Thermal Stratification ◽  
Oxygen Demand ◽  
Limiting Factor ◽  
Alkaline Ph ◽  
A Value ◽  
Sodium Calcium ◽  
Calcium Bicarbonate ◽  
Laboratory Results

AIM: The Escaba dam is located in the south of the Tucumán province, Argentina, at 650 m above sea level. It has an extension of 541 ha. and a depth of 65 m and its tributaries are the Chavarría, Las Moras, El Chorro and Singuil rivers. The climate is mild with dry winters and rainy summers. The objective of this study was to characterize physicochemical parameters in the limnetic zone of the dam and the mouths of the tributaries to determine the water quality. METHODS: Seasonal sampling was carried out between August 2010 and May 2012. Temperature, transparency, pH and electrical conductivity were field measured, whereas dissolved oxygen, biochemical oxygen demand (BOD5), major ion constituents and nitrogen and phosphate compounds were analyzed at the laboratory. RESULTS: The water was classified as sodium-calcium-bicarbonate with neutral to alkaline pH, and thermal stratification during spring and summer. The water assayed was well oxygenated except for the bottom of the limnetic zone during the summer months. Lowest transparency was measured in the El Chorro River in November 2011 (0.12 m) and highest degree of transparency in the Singuil River during the winter of 2010 (4.1 m). The waters assayed showed weak mineralization with conductivities between 83 and 218 µS.cm-1. Maximum BOD5 value (183 mg.L-1) was measured in the Singuil River in spring 2010. Highest values for the different nitrogen compounds were as follows: 7 mg NO3-.L-1 at the bottom of the limnetic zone in August 2010, 0.07 mg NO2-.L-1 in the Las Moras River in May 2011 and 1.8 mg NH4+.L-1 in the Chavarría River in March 2011. During the summer of 2012 orthophosphate reached a value of 0.22 mg.L-1 at the bottom of the limnetic zone. The TN/TP ratio revealed that phosphate was generally the limiting factor and rarely nitrogen. CONCLUSIONS: Considering the TN, TP and transparency parameters the ecosystem was classified as hypertrophic. PCA allowed a seasonal differentiation of the sites, and components 1 and 2 classified the samples according to nutrient gradient, dissolved oxygen, BOD5 and temperature.

Zinc Regulation in the Lobster Homarus Gammarus: Importance of Different Pathways of Absorption and Excretion

1986 ◽  
Vol 66 (1) ◽  
pp. 175-199 ◽  
Author(s):  
G. W. Bryan ◽  
L. G. Hummerstone ◽  
Eileen Ward
Keyword(s):  
Sea Water ◽  
Carcinus Maenas ◽  
The Body ◽  
Shore Crab ◽  
Freshwater Crayfish ◽  
Uptake Mechanism ◽  
Major Pathway ◽  
Homarus Gammarus ◽  
Wide Range ◽  
Body Concentration

Zinc is one of the most important of the essential trace metals and more than 90 zinc-containing enymes and proteins have been discovered: furthermore, zinc increases the activity of many other enzymes (Vallee, 1978). It is not surprising, therefore, that in some groups of animals the body concentration is regulated against fluctuations in intake. Decapod crustaceans comprise one such group, although the ways in which regulation is achieved vary from species to species. In the freshwater crayfish, Austropotamobius pallipes, excretion in the faeces is a major pathway for removing zinc (Bryan, 1967a) whereas in the shore crab Carcinus maenas losses over the body surface also assume considerable importance (Bryan, 1966). On the other hand, preliminary work on the lobster Homarus gammarus (formerly H. vulgaris) suggests that in this species urinary excretion plays a major role in regulation (Bryan, 1964). The present work continues the study of zinc regulation in lobsters and its main aims are: (1) to measure rates of absorption from sea water over a wide range of concentrations and study the uptake mechanism; (2) to examine absorption from the stomach under different conditions; (3) to determine the relative importance of different pathways for the removal of zinc in response to various levels of intake.

The Physiology of the Antennal Gland of Carcinus Maenas (L.)

1969 ◽  
Vol 51 (1) ◽  
pp. 1-10
Author(s):  
R. BINNS
Keyword(s):  
Sea Water ◽  
Carcinus Maenas ◽  
Urine Concentration ◽  
Antennal Gland ◽  
Rate Of Increase ◽  
Urine Production ◽  
Urine Concentrations

1. U/B ratios for inulin and sorbitol have been measured in 100%, 75% and 50% sea water. 2. When Carcinus is in 100% sea water, a U/B ratio of 1 for both sorbitol and inulin is reached and maintained after 40 and 115 hr. respectively. A reason for this difference is suggested. 3. In dilute media the rate of increase of U/B ratio for both molecules is more rapid than in 100% sea water. For instance, in 50% sea water the inulin U/B ratio is 1 after 50-60 hr. Sorbitol ratios are generally less than 1 in dilute sea water and a possible explanation of this is given. 4. In any particular concentration of sea water blood and urine concentrations of injected solutes fall at approximately the same rate once the maximum urine concentration has been reached. 5. It is concluded that primary urine production in Carcinus is by a filtration mechanism and that reabsorption of water from the urine does not normally occur.

The Mechanical Properties of the Cell Surface

1955 ◽  
Vol 32 (4) ◽  
pp. 734-750 ◽  
Author(s):  
J. M. MITCHISON ◽  
M. M. SWANN
Keyword(s):  
Cell Surface ◽  
Young’S Modulus ◽  
Sea Water ◽  
Young's Modulus ◽  
Contractile Ring ◽  
A Value ◽  
Sudden Rise ◽  
Slow Rise ◽  
Stage Yield ◽  
Sperm Aster

1. Measurements with the cell elastimeter on the stiffness of the cell membrane of fertilized sea-urchin eggs show the following general features. There is a sudden rise at fertilization, followed by a fall during the early sperm aster stage to the lowest value reached during development (a Young's modulus of about 0.58 x 104 dynes/cm.2). The stiffness rises slowly until metaphase, after which it rises rapidly to reach a maximum during late anaphase and early cleavage (6.81 x 104 dynes/cm.2). During the later stages of cleavage the stiffness falls again and reaches a value in the second interphase which is about twice as high as in the first interphase. Masurements on naked eggs in calcium-free sea water indicate that the slow rise in metaphase is due to the development of the hyaline layer. 2. Measurements on swollen and shrunken eggs at cleavage indicate that there is no interal pressure in the eggs at this stage, but similar experiments with eggs at the sperm aster stage yield anomalous results. Observations on the wrinkling point in shrunken eggs show that the maximum possible internal pressure is 19 dynes/cm.2 for sperm aster eggs and 500 dynes/cm.2 for cleaving eggs. 3. The bearing of these results on various theories of the mechanism of cleavage is briefly discussed. The rise in Young's modulus of the whole cell surface at cleavage argues against theories depending on the action of the spindle and asters, and against theories proposing a contractile ring in the surface. The rise is, however, what might be expected on the basis of the expanding membrane theory.

Extracellular Fluid Volume Changes in Carcinus Maenas during Acclimation to Low and High Environmental Salinities

1982 ◽  
Vol 99 (1) ◽  
pp. 161-173
Author(s):  
R. R. HARRIS ◽  
M. B. ANDREWS
Keyword(s):  
Sea Water ◽  
Carcinus Maenas ◽  
Extracellular Fluid ◽  
Blood Sampling ◽  
Extracellular Fluid Volume ◽  
Clearance Rates ◽  
Volume Changes ◽  
Marker Distribution ◽  
Water Contents

Changes in extracellular fluid (ECF) volume of Carcinus maenas (L.) were studied in vivo during acclimation to low and high environmental salinities. Initial investigations showed that there was a rapid equilibration into this compartment of the ECF markers used ([3H]inulin and [14C]hydroxymethyl inulin). Earlier reports of a relatively slow marker distribution, indicated from clearance curves, can be explained by high clearance rates occurring when frequent blood sampling was carried out. After transfer of the crabs to media hyposmotic to the haemolymph, ECF volumes decreased transiently to 74.8% of the initial volume, but within 40 h in 26% sea water original volumes were restored. Calculation of intracellular water contents suggests that a volume limitation phase precedes the regulatory return to the original volume. In hyperosmotic media, the ECF volumes increased significantly (to a maximum of 143%) but, in contrast to the response in hyposmotic conditions, showed only a partial return to the original volumes.

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