Urine Production by the Antennal Glands of Palaemonetes Varians (Leach)

1955 ◽  
Vol 32 (2) ◽  
pp. 408-422
Author(s):  
GWYNETH PARRY
Keyword(s):  
Sea Water ◽  
External Medium ◽  
Urine Flow ◽  
Urine Production ◽  
Antennal Glands

1. Four methods for estimating the rate of urine flow in Palaemonetes varians are described. 2. The rate is minimal when the external medium is approximately isotonic with the blood. All methods indicate that the rate increases progressively with increasing dilution of the external medium below 50% sea water. There is some evidence to suggest that the rate increases in hypertonic external media. 3. These results are discussed in relation to estimates of the urine production in some other Crustacea and in relation to the ecology of the genus Palaemonetes.

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

1969 ◽  
Vol 51 (1) ◽  
pp. 11-16
Author(s):  
R. BINNS
Keyword(s):  
Body Weight ◽  
Sea Water ◽  
Carcinus Maenas ◽  
Urine Flow ◽  
The Body ◽  
Antennal Gland ◽  
Urine Production ◽  
The Mean ◽  
Gland Function ◽  
Water Clearance

1. The space measured by inulin distribution, the ‘inulin volume’, has been determined, and represents approximately 20% of the body weight in crabs ranging in size from 20.0 to 57.2 g. 2. After the injection of labelled inulin into crabs, the increase in activity of the medium is equal to the fall in blood inulin in all dilutions of sea water. Clearance of inulin from the blood is due only to urine production, and therefore the molecule can be used for quantitative investigations of antennal gland function. 3. Urine production in various concentrations of sea water has been determined by measuring the clearance of inulin from the blood and the rates at which the tracer appeared in the external media. By these methods the mean rate of urine production in 100% sea water was estimated to be 4.4% body weight per day. In dilute sea water the rate of urine production increases; for example, in 50% sea water the urine flow is four times greater than in normal sea water.

Water Uptake and Loss in Relation to the Salinity of the Medium in the Amphipod Crustacean Gammarus Duebeni

1973 ◽  
Vol 58 (1) ◽  
pp. 149-163
Author(s):  
A. P. M. LOCKWOOD ◽  
C. B. E. INMAN
Keyword(s):  
Body Surface ◽  
Sea Water ◽  
Tritiated Water ◽  
Prima Facie ◽  
Urine Flow ◽  
The Body ◽  
Osmotic Gradient ◽  
Prima Facie Case ◽  
Urine Production ◽  
Water Saturated

1. The water fluxes across the body surface and the rate of urine production have been studied in the euryhaline amphipod Gammarus duebeni. 2. Urine flow rates (fPOs) have been determined from measurements of loss of [131I]sodium diatrizoate from the body, and the expected urine flow (fPdiff) has been calculated from determinations of the osmotic gradient between blood and medium and the flux of tritiated water. 3. For animals in 2% and 40% sea water the ratio fPOs/fPdiff are 1.16 and 1.44 respectively, and thus approximate fairly closely to unity. This implies that in these media the water subsequently excreted as urine enters the body by osmosis and that there is little interference with the free diffusion of water at the body surface due to passage through long pores or across unstirred layers. 4. In sea water the ratio fPOs/fPdiff is normally (assuming an osmotic gradient of 10 m-osmoles) almost twice unity but urine production is approximately halved when the animals are exposed to sea water saturated with an inhibitor of active sodium uptake (thionine). 5. It is suggested that there is a prima facie case for assuming that part of the fluid subsequently excreted by this species, when in sea water, is taken into the body initially by a process dependent upon active ion transport.

Internal Volume and Pressure Regulation in Carcinus Maenas

1978 ◽  
Vol 74 (1) ◽  
pp. 123-132
Author(s):  
J.R. W. NORFOLK
Keyword(s):  
Internal Pressure ◽  
Sea Water ◽  
Alternative Hypothesis ◽  
Carcinus Maenas ◽  
External Environment ◽  
Mean Value ◽  
Urine Flow ◽  
Pressure Regulation ◽  
Urine Production ◽  
Internal Volume

In Carcinus, in dilute media, internal volume and pressure were found to be regulated by the intermittent release of urine which maintained internal pressure at a mean value of 15 cm water, compared to a mean value of 10 cm for crabs in sea water. Following transfer of crabs from 100% to 50% sea water, urine production (measured by a continuous collection method) was observed to increase within 5 min of dilution of the medium, by which time the estimated increase in internal pressure would have been only 1.3 cm water. Such a pressure increase is considered inadequate to stimulate a rise in urine production, since artificially raising internal pressure of crabs in sea water did not result in an increase in urine flow, until the pressure was in excess of 20 cm water. The results support the hypothesis that the stimulus to increase urine production by crabs in dilute media is not raised internal pressure due to osmotic influx of water. An alternative hypothesis, namely that of changes in urine production being in response to direct monitoring of the external environment, is suggested.

The Formation of Urine by the Prosobranch Gastropod Mollusc Viviparus Viviparus Linn

1965 ◽  
Vol 43 (1) ◽  
pp. 39-54
Author(s):  
C. LITTLE
Keyword(s):  
Blood Pressure ◽  
Sea Water ◽  
External Medium ◽  
Tap Water ◽  
Pericardial Fluid ◽  
Blood Concentrations ◽  
Gastropod Mollusc ◽  
Urine Production ◽  
Viviparus Viviparus ◽  
Pericardial Pressure

1. The urine of Viviparus is hypotonic to the blood by about 30 mM./l. NaCl in tap water, and remains hypotonic in concentrations of up to 10% sea water. 2. The rate of production of urine is between 0·25 and 0·91 µl./g./min. in tap water at 19° C. The rate decreases in proportion to the decrease in osmotic difference between blood and external medium. Viviparus may be able to detect changes in salt concentration of the external medium and alter its rate of urine production accordingly. 3. Pericardial fluid is similar to blood in composition; the rate of flow of pericardial fluid through the reno-pericardial canal is proportional to the blood pressure; and when inulin is injected into the blood, concentrations in blood and pericardial fluid are approximately the same. For these reasons it is supposed that blood is filtered through the heart into the pericardium. 4. About 20 mM./l. NaCl, and probably some water, are reabsorbed in the kidney. Liquid is passed through the kidney by rhythmic contractions of the kidney musculature. Pericardial pressure does not influence the overall rate of urine production but blood pressure does have an effect. 5. About 5 mM./ NaCl, and probably a little water, are reabsorbed in the ureter.

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.

Intramembranous absorption rate is unaffected by changes in amniotic fluid composition

2005 ◽  
Vol 288 (5) ◽  
pp. F964-F968 ◽  
Author(s):  
D. Anderson ◽  
Q. Yang ◽  
A. Hohimer ◽  
J. Faber ◽  
G. Giraud ◽  
...  
Keyword(s):  
Amniotic Fluid ◽  
Flow Measurement ◽  
Control Period ◽  
Ringer Solution ◽  
Urine Flow ◽  
Fluid Composition ◽  
Fetal Sheep ◽  
Urine Production ◽  
Blood Pressures ◽  
Vascular Catheters

Experiments were performed to determine the effect of amniotic fluid dilution on the rate of intramembranous absorption. Seven fetal sheep at 118 days gestation were instrumented with a shunt between the trachea and esophagus and arterial and venous vascular catheters. In addition, the urachus of the fetal bladder was ligated, and a catheter was placed in the bladder. Ligation of the urachus does not interfere with urine flow into the amnion. After 5 days of recovery, fetuses were randomly assigned to one of two protocols; all fetuses completed both protocols. In the fetuses in the control period, continuous urine flow measurement was begun. In the fetuses assigned to the isovolumic dilution protocol, continuous urine flow measurement was also begun and, in addition, amniotic fluid was continually exchanged with lactated Ringer solution on an isovolumic basis. After 3–4 days, fetal blood pressures and amniotic fluid volumes were determined. Amniotic fluid volumes were determined by drainage. Each fetus was then assigned to the remaining protocol. The presence of the tracheal-esophageal shunt and the ligation of the urachus allowed the rate of intramembranous absorption to be calculated. Isovolumic exchange showed no effect on fetal vascular pressures, blood-gas values, or urine production. We could demonstrate no effect of isovolumic dilution of amniotic fluid on its volume. However, we were able to demonstrate an inverse relationship between amniotic fluid volume and intramembranous absorption ( P < 0.02).

The opening response of mussels (Mytilus edulis) exposed to rising sea-water concentrations

1981 ◽  
Vol 61 (3) ◽  
pp. 667-678 ◽  
Author(s):  
John Davenport
Keyword(s):  
Mytilus Edulis ◽  
Sea Water ◽  
External Medium ◽  
Mantle Cavity ◽  
Low Salinity ◽  
Medium Exchange ◽  
Mantle Edge

When exposed to water of low salinity specimens of Mytilus edulis L. keep their shell valves tightly closed; they do not gape periodically to test the external medium. Exchange of salts and water between the mantle cavity and the environment is thus minimized. Rising salinities are registered by diffusion of salts to the tentaculate portion of the inhalent siphon and not to any other portion of the mantle edge or to any more deeply located structures.

scholarly journals Aedes Aegypti: Energetics of Osmoregulation

1982 ◽  
Vol 101 (1) ◽  
pp. 135-141 ◽  
Author(s):  
H.A. EDWARDS
Keyword(s):  
Oxygen Consumption ◽  
Energy Cost ◽  
Sea Water ◽  
External Medium ◽  
Minimum Energy ◽  
Body Volume ◽  
Wet Weight ◽  
Minimum Energy Cost ◽  
Anal Papillae ◽  
Theoretical Minimum

1. Oxygen consumption of A. aegypti larvae, about 210 mul l g−1 tissue wet weight h−1, does not change when the salinity of the environment is changed. The number of mitochondria in the anal papillae, a salt-absorbing epithelium, increases as the external medium is diluted. There is no difference in oxygen consumption between isolated anal papillae in 0, 2 and 20% sea water. The papillae represent about 5% of body volume and their oxygen consumption is about 2% of the animal's total. The theoretical minimum energy cost of osmoregulation is four orders of magnitude smaller than the measured figure for the anal papillae alone. Osmoregulatory phenomena which would explain the recorded observations are discussed.

The Water Balance of a Serpulid Polychaete, Mercierella Enigmatica (Fauvel)

1974 ◽  
Vol 60 (2) ◽  
pp. 321-330
Author(s):  
HELEN LE B. SKAER
Keyword(s):  
Body Weight ◽  
Water Balance ◽  
Blood Volume ◽  
Blood Concentration ◽  
Volume Regulation ◽  
Sea Water ◽  
External Medium ◽  
Wide Range ◽  
Natural Range ◽  
Passive Movements

1. The serpulid polychaete Mercierella enigmatica is found naturally in a wide range of salinities - from fresh water to 150% sea water (&lt; 1-55‰ &lt; 25.8-1421 mOsm). 2. Changes in body weight, blood volume and blood osmolality have been measured both during and after equilibration of animals with media of altered salinity. 3. The blood remains similar in osmolality to the external medium over a very wide range of salinity (43-1620 mOsm); osmoregulation occurs only at the lowest limit of the natural range. 4. Mercierella enigmatica shows volume regulation; after 4 days of equilibration with a medium of altered salinity the blood volume shows much less change than the blood concentration. 5. During equilibration there appear to be passive movements of both water and salts between the animals and their environment.

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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