scholarly journals Intestinal Na+ and Cl- levels control drinking behavior in the seawater-adapted eel Anguilla japonica

1996 ◽  
Vol 199 (3) ◽  
pp. 711-716 ◽  
Author(s):  
M Ando ◽  
K Nagashima
Keyword(s):  
Sea Water ◽  
Direct Action ◽  
Choline Chloride ◽  
Drinking Behavior ◽  
Anguilla Japonica ◽  
Urine Flow ◽  
Perfusion Medium ◽  
Drinking Rate ◽  
Gastrointestinal Fluid ◽  
High Concentrations

To analyze drinking mechanisms in seawater teleosts, seawater-adapted eels were used as a model system. When the intestine of the eel was perfused with iso-osmotic mannitol, the eels drank sea water. However, when the perfusion medium was switched to iso-osmotic NaCl, seawater drinking was depressed. This depression was observed even after blocking NaCl absorption across the intestine by replacement of the perfusate with choline chloride or by treatment with furosemide, an inhibitor of NaCl and water absorption across the eel intestine. Furthermore, depression of drinking rate preceded an increase in urine flow by over 1 h. These results indicate that this depression is not due to a recovery of blood volume and suggest that intestinal Cl- itself inhibits drinking. Direct action of luminal Cl- on drinking behavior was further supported by the observation that perfusion with iso-osmotic NMDG-HCl, Tris-HCl, choline chloride and RbCl all inhibited seawater drinking. When NaCl in the perfusion medium was replaced with sodium acetate, sodium butyrate, sodium methylsulfate or NaSCN, the drinking rate was enhanced threefold, suggesting that Na+ itself stimulates drinking in the absence of Cl-. In the present study, concentrations of Na+ and Cl- in the swallowed fluid were also measured simultaneously. As the drinking rate was enhanced, the Na+ and Cl- concentrations in the gastrointestinal fluid were increased. On the basis of these results, it seems possible that high concentrations of Cl- in the intestine reduce the drinking rate, thus lowering esophageal Cl- concentration due to desalination of the ingested sea water. When Cl- concentration in the intestine falls below a certain level, Na+ will stimulate seawater drinking again.

Glycerol and water balance in a near-isosmotic teleost, winter-acclimatized rainbow smelt

1993 ◽  
Vol 71 (9) ◽  
pp. 1849-1854 ◽  
Author(s):  
James A. Raymond
Keyword(s):  
Water Balance ◽  
Freezing Point ◽  
Urine Flow ◽  
Osmerus Mordax ◽  
Rainbow Smelt ◽  
Water Losses ◽  
Drinking Rate ◽  
Osmotic Water ◽  
High Concentrations ◽  
Reduced Drinking

Rainbow smelt, Osmerus mordax, have previously been shown to produce high concentrations of glycerol in winter to avoid freezing, becoming almost isosmotic in a marine environment when temperatures reach the freezing point of seawater. Here it is shown that osmotic water losses, as shown by drinking rate, decrease dramatically in winter as a result of the increased osmolality. Urine flow also appears to decrease in winter in response to reduced drinking. Glycerol is lost through the skin and gills, and probably through intestinal discharge, at total rates ranging from 3.5 to 9.5 mg∙100 g−1∙h−1. Combined permeabilities to glycerol of the gills and skin in the head were in the range 0.9–2.6 × 10−7 cm∙s−1. Glycerol concentrations, efflux, and permeability of the gills were comparable to those for urea in marine elasmobranchs. However, mechanisms for conserving the two osmolytes may differ.

Osmoregulation of Lampetra Fluviatilis L. and Petromyzon Marinus (Cyclostomata) in Hyperosmotic Solutions

1970 ◽  
Vol 53 (1) ◽  
pp. 231-243
Author(s):  
ALAN D. PICKERING ◽  
R. MORRIS
Keyword(s):  
Alimentary Canal ◽  
Sea Water ◽  
Petromyzon Marinus ◽  
Urine Flow ◽  
Sodium Potassium ◽  
Monovalent Ions ◽  
Anadromous Migration ◽  
Calcium Magnesium ◽  
High Concentrations ◽  
Osmoregulatory Mechanism

1. Freshly caught migrating lampreys were placed in 50% sea water and their method of osmoregulation was analysed. Some osmoregulated more successfully than others. 2. Water balance is maintained by a mechanism involving the drinking of large quantities of water (up to 99.5 ml/kg/day). Sodium, potassium and chloride are absorbed by the intestine (often against a concentration gradient) with the subsequent uptake of water. Divalent ions are not readily absorbed by the intestine and there is some evidence for the secretion of magnesium and sulphate into the gut lumen. 3. The limited urine flow (up to 6.2 ml/kg/day) is used for the excretion of calcium, magnesium and sulphate in high concentrations, but the urine is never hyperosmotic to the blood. The urinary excretion of monovalent ions is not sufficient to eliminate those entering by the intestine and extrarenal excretion at the gills must presumably occur. 4. The breakdown of this osmoregulatory mechanism during the anadromous migration involves: an increase in the permeability of the integument to water, breakdown of the swallowing mechanism which is not dependent upon the occlusion of the alimentary canal, a reduction in the ability to absorb monovalent ions and water from the ingested 50% sea water, and a loss in the large mitochondria-rich ‘chloride output cells’ of the gills. 5. The similarities between the mechanisms of ‘marine’ osmoregulation of lampreys and teleosts are discussed in terms of the evolution of the two groups, and it is concluded that almost identical osmoregulatory mechanisms have evolved independently.

Sodium, Chloride and Water Balance of the Intertidal Teleost, Xiphister Atropurpureus

1967 ◽  
Vol 47 (3) ◽  
pp. 519-524
Author(s):  
DAVID H. EVANS
Keyword(s):  
Sodium Chloride ◽  
Water Balance ◽  
Sea Water ◽  
Urine Flow ◽  
Drinking Rate ◽  
Euryhaline Teleost ◽  
Xiphister Atropurpureus ◽  
Low Rate

1. The rate of loss of sodium, chloride and water via the urine and the rate of intake of sodium, chloride and water by ingestion of the medium was determined for the euryhaline teleost, Xiphister atropurpureus. 2. The urinary losses of sodium and chloride were approximately 0.5 mM/kg. fish/day in both 100 % sea water (480 mM-Na/kg.) and 10% sea water. The ingestion of sodium and chloride by drinking the medium amounted to approximately 4 mM/kg. fish/day in 100% sea water and approximately 0.1 mM/kg. fish/day in 10% sea water. 3. The low rate of urine flow in 10 % sea water and the low drinking rate in 100 % sea water indicate a relative impermeability to water in both salinities.

scholarly journals Adaptations to a Terrestrial Existence by the Robber Crab Birgus Latro: VI. The Role of the Excretory System in Fluid Balance

1990 ◽  
Vol 152 (1) ◽  
pp. 505-519 ◽  
Author(s):  
PETER GREENAWAY ◽  
H. H. TAYLOR ◽  
S. MORRIS
Keyword(s):  
Drinking Water ◽  
Fresh Water ◽  
Fluid Balance ◽  
Filtration Rate ◽  
Sea Water ◽  
Urine Flow ◽  
Water Losses ◽  
Drinking Rate ◽  
The Difference

Primary urine is formed by filtration in the antennal organ of Birgus latro L. Urine isosmotic with the haemolymph is released into the anterior branchial chambers where substantial reabsorption of water and ions may occur. Some of the branchial fluid is ingested and the remainder (final excretory fluid, P) is released. Crabs supplied with fresh water have a low drinking rate (1.82 ml 100 g−1 day−1). Primary urine is partially reabsorbed (27%) in the antennal organ and urine flow (4.48 ml 100 g−1 day−1) is significantly lower than filtration rate (5.77 ml 100 g−1 day−1). The volume of P released is small in crabs drinking fresh water (0.45 ml 100 g−1 day−1) and the fluid is dilute (≈25 mmol l−1 NaCl). The difference between P flow and drinking rate (1.37 ml 100 g−1 day−1) represents evaporative and faecal water losses. Provision of saline drinking water (300, 600 or 1000 mosmol kg−1 sea water) doubles rates of drinking, filtration and urine flow and increases P flow fourfold. Evaporative/faecal water loss remains constant. Reabsorption of salts from the P rapidly decreases when saline media are provided for drinking.

COASTAL AND ESTUARINE SEDIMENT DYNAMICS IN THE MEZEN BAY AND ESTUARIES MEZEN AND KULOY

2018 ◽  
Author(s):  
Н. Демиденко ◽  
N. Demidenko
Keyword(s):  
River Water ◽  
River Discharge ◽  
Sea Water ◽  
Sediment Dynamics ◽  
Estuarine Sediment ◽  
Sea Surface ◽  
Cross Sectional ◽  
Sand Waves ◽  
Tidal Estuaries ◽  
High Concentrations

In the Mezen bay and estuaries Mezen and Kuloy can be high concentrations of mud suspension there, involving the formation at times mobile suspensions and settled mud. Within estuaries the river water is mixed with the sea water by the action of tidal motions, by waves on the sea surface and by the river discharge forcing its way to the sea. Nearly all shallow tidal estuaries, where currents exceed about 1,0m s-1 and where sand is present, have sand waves. Sand waves have a variety of cross-sectional and plan forms.

Effects of homologous atrial natriuretic peptide on drinking and plasma ANG II level in eels

1998 ◽  
Vol 275 (5) ◽  
pp. R1605-R1610 ◽  
Author(s):  
Takamasa Tsuchida ◽  
Yoshio Takei
Keyword(s):  
Atrial Natriuretic Peptide ◽  
Natriuretic Peptide ◽  
Direct Action ◽  
Sodium Concentration ◽  
Saline Infusion ◽  
Plasma Sodium ◽  
Ang Ii ◽  
Drinking Rate ◽  
Plasma Sodium Concentration ◽  
Atrial Natriuretic

The effects of eel atrial natriuretic peptide (ANP) on drinking were investigated in eels adapted to freshwater (FW) or seawater (SW) or in FW eels whose drinking was stimulated by a 2-ml hemorrhage. An intra-arterial infusion of ANP (0.3–3.0 pmol ⋅ kg−1 ⋅ min−1), which increased plasma ANP level 1.5- to 20-fold, inhibited drinking dose dependently in all groups of eels. The drinking rate recovered to the level before ANP infusion within 2 h after infusate was replaced by saline. The inhibition at 3.0 pmol ⋅ kg−1 ⋅ min−1was profound in FW eels and hemorrhaged FW eels, whereas significant drinking still remained after inhibition in SW eels. Plasma ANG II concentration also decreased dose dependently during ANP infusion and recovered to the initial level after saline infusion in all groups of eels. The decrease at 3.0 pmol ⋅ kg−1 ⋅ min−1was large in FW eels and hemorrhaged FW eels compared with that of SW eels. Thus the changes in drinking rate and plasma ANG II level were parallel during ANP infusion. Plasma sodium concentration and osmolality decreased during ANP infusion in SW and FW eels, and they were restored after saline infusion. In hemorrhaged FW eels, however, ANP infusion did not alter plasma sodium concentration and osmolality. Hematocrit did not change during ANP infusion in any group of eels. Collectively, ANP infusion at physiological doses decreased drinking rate and plasma ANG II concentration in parallel in both FW and SW eels. It remains undetermined whether the inhibition of drinking is caused by direct action of ANP or through inhibition of ANG II, which is known as a potent dipsogen in all vertebrate species, including eels.

The contribution of nitrate respiration to the energy budget of the symbiont-containing clam Lucinoma aequizonata: a calorimetric study

1996 ◽  
Vol 199 (2) ◽  
pp. 427-433
Author(s):  
U Hentschel ◽  
S Hand ◽  
H Felbeck
Keyword(s):  
Heat Production ◽  
Sea Water ◽  
Anaerobic Respiration ◽  
Gill Tissue ◽  
Nitrate Respiration ◽  
Heat Output ◽  
Marine Bivalve ◽  
Calorimetric Study ◽  
Perfusion Medium ◽  
Terminal Electron Acceptor

Heat production and nitrate respiration rates were measured simultaneously in the gill tissue of Lucinoma aequizonata. This marine bivalve contains chemoautotrophic, intracellular, bacterial symbionts in its gill tissue. The symbionts show constitutive anaerobic respiration, using nitrate instead of oxygen as a terminal electron acceptor. An immediate increase in heat production was observed after the addition of nitrate to the perfusion medium of the calorimeter and this was accompanied by the appearance of nitrite in the effluent sea water. The nitrate-stimulated heat output was similar under aerobic and anaerobic conditions, which is consistent with the constitutive nature of nitrate respiration. The amount of heat released was dependent on the concentration of nitrate in the perfusion medium. At nitrate concentrations between 0.5 and 5 mmol l-1, the total heat production was increased over twofold relative to unstimulated baseline values. A mean (±s.e.m.) experimental enthalpy of -130±22.6 kJ mol-1 nitrite (N=13) was measured for this concentration range.

The effect of external salinity on drinking rate and rectal secretion in the larvae of the saline-water mosquito Aedes taeniorhynchus

1977 ◽  
Vol 66 (1) ◽  
pp. 97-110
Author(s):  
T. J. Bradley ◽  
J. E. Phillips
Keyword(s):  
Sea Water ◽  
External Medium ◽  
Narrow Range ◽  
Saline Water ◽  
Fluid Secretion ◽  
Osmotic Concentration ◽  
Drinking Rate ◽  
Aedes Taeniorhynchus ◽  
External Salinity ◽  
Kinetics Of

1. The drinking rate of the saline-water mosquito larva Aedes taeniorhyncus (100 nl.mg-1.h-1) is unaffected by the salinity of the external medium, but is directly proportional to the surface area of the animal. 2. Haemolymph Na+, Mg2+, K+, Cl-, SO42- and osmotic concentrations were measured in larvae adapted to 10%, 100% and 200% seawater and were found to be regulated within a narrow range. 3. With the exception of potassium, ionic concentrations in rectal secretion were found to increase with increasing concentrations of the sea water in which larvae were reared. 4. The osmotic concentration of rectal secretion was unaffected by changes in haemolymph osmotic concentration but did rise when sodium or chloride concentrations of the haemolymph were increased. High levels of these ions also stimulated the rate of fluid secretion. 5. Transport of chloride and sodium by the rectum exhibits the kinetics of allosteric rather than classical enzymes.

Effects of stimulation on steroid output and perfusion medium flow rate in the isolated perfused rat adrenal gland in situ

1986 ◽  
Vol 109 (2) ◽  
pp. 279-285 ◽  
Author(s):  
J. P. Hinson ◽  
G. P. Vinson ◽  
B. J. Whitehouse ◽  
G. M. Price
Keyword(s):  
Flow Rate ◽  
Zona Glomerulosa ◽  
Clear Correlation ◽  
Perfusion Medium ◽  
Flow Rates ◽  
Vascular Elements ◽  
Medium Flow ◽  
High Concentrations ◽  
Adrenal Vasculature

ABSTRACT Using the in-situ, isolated, perfused rat adrenal system, the actions of adrenal stimulants on steroidogenesis and perfusion medium flow rates (under constant perfusion pump conditions) have been studied. In a series of 100 experiments, initial rates of corticosterone output and flow rates were found to be positively correlated, although there was no such relationship between initial rates of aldosterone output and flow rates. Furthermore, in stable perfusion conditions, bolus injections of ACTH increased both flow rate and steroid output in a dose-related manner. In individual experiments there was a clear correlation between corticosterone and flow, but the association between aldosterone secretion rate and flow was less evident. It is possible that this discrepancy arises because of temporal differences in the responses of these two steroids. Flow was also stimulated by dibutyryl cyclic AMP (dbcAMP), with correlations with steroid output similar to ACTH, but the specific zona glomerulosa stimulants angiotensin II amide and potassium ions had, if anything, inhibitory effects on flow, but only at high concentrations. The data suggest that ACTH and dbcAMP evoke specific responses in the adrenal vasculature, resulting in relatively decreased intraglandular vascular resistance. They furthermore suggest that the secretory functions of the inner adrenocortical zones are subject to the additional control of vascular elements in the intact gland. J. Endocr. (1986) 109, 279–285

Kidney Function in the Crab-Eating Frog (Rana Cancrivora)

1962 ◽  
Vol 39 (1) ◽  
pp. 167-177 ◽  
Author(s):  
KNUT SCHMIDT-NIELSEN ◽  
PING LEE
Keyword(s):  
East Asia ◽  
Glomerular Filtration ◽  
Kidney Function ◽  
Sea Water ◽  
Tubular Reabsorption ◽  
Urine Flow ◽  
South East Asia ◽  
Considerable Part ◽  
Osmotic Concentration ◽  
Full Strength

1. A study has been made of kidney function in the crab-eating frog, Rana cancrivora, of south-east Asia. 2. This frog can live in full-strength sea water; in such concentrated media its blood is slightly hypertonic to the medium, and a considerable part of the osmotic concentration is due to urea. 3. In concentrated media the excretion of urea is greatly diminished. This is not due to active tubular reabsorption of urea, but primarily to a low urine flow caused by increased tubular reabsorption of water and reduced glomerular filtration. 4. In concentrated media, as compared with dilute media, only a few percent of the filtered urea appears in the urine. 5. Osmoregulation of the crab-eating frog in sea water resembles that of elasmobranchs except in that there is no evidence of active tubular reabsorption of urea in the frog.

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