A Micropuncture Study of Kidney Function in the River Lamprey Lampetra Fluviatilis Adapted to Sea Water

1980 ◽  
Vol 88 (1) ◽  
pp. 239-248
Author(s):  
A. G. LOGAN ◽  
R. MORRIS ◽  
J. C. RANKIN

Micropuncture techniques have been used to investigate kidney function in lampreys adapted to hyperosmotic media. Plasma electrolyte concentrations were maintained well below corresponding concentrations in the external environment. Urine composition was variable, but generally showed high concentrations of magnesium, sulphate and chloride ions. Lampreys in 50% sea water produced urine which was hypo or iso-osmotic to plasma, whereas those in 100% sea water produced hyperosmotic urine. Urine flow rate in 50% sea water was one tenth of that in fresh water, due to a reduction in filtration rate and an increase in water reabsorption by the kidney. As in fresh water, little if any filtered water was reabsorbed by the proximal segment. Almost 90% of filtered water was reabsorbed by the kidney of 100% sea water lampreys and most of this must have occurred in the distal and collecting segments.

1980 ◽  
Vol 85 (1) ◽  
pp. 137-147
Author(s):  
A. G. LOGAN ◽  
R. J. MORIARTY ◽  
J. C. RANKIN

Micropuncture techniques have been used to investigate the role of each nephron segment in the river lamprey. The proximal segment reabsorbed no more than 10% of filtered water and tubular fluid here was iso-osmotic to plasma, at about 250 m-osmol. Further water reabsorption occurred in later nephron segments so that 44% of all filtered water was reabsorbed. Dilution of tubular fluid began in the ascending limb of the nephron loop and continued in the distal and collecting segments, so that 96% and 97.5% of filtered sodium and chloride, respectively, was reabsorbed by the kidney. Lampreys produce 337 ml kg−1 day−1 of a dilute urine (31.2 m-osmol) and the urinary ducts appear not to modify the composition of this urine.


1974 ◽  
Vol 61 (3) ◽  
pp. 737-747 ◽  
Author(s):  
TETSUYA HIRANO

1. Internal as well as external factors affecting water ingestion in the eel were analysed using oesophagus-cannulated eels. 2. Acute withdrawal of the blood induced an immediate drinking response in the freshwater eel, whereas infusion of a large amount of hypertonic saline interrupted the copious drinking observed in the seawater eel. 3. The freshwater eel responded to slow infusion of hypertonic NaCl solution by constant drinking. 4. Inhibition of drinking was observed in the seawater eel by distension of the stomach or intestine with isotonic mannitol solution. 5. The freshwater eel started drinking immediately after transfer to sea water, and stopped drinking immediately after return to fresh water. 6. Application of various salt solutions revealed that chloride ions are responsible for the induction of drinking in sea water. 7. Stimulation of drinking by chloride ions and inhibition by fresh water may be an anticipatory drinking behaviour, which facilitates adaptation of eels to both sea water and fresh water.


1999 ◽  
Vol 202 (8) ◽  
pp. 939-946 ◽  
Author(s):  
J.A. Brown ◽  
J.C. Rankin

Previous studies have suggested that in the lamprey Lampetra fluviatilis, in contrast to teleost fish, all glomeruli are actively filtering. In the present study, we have applied the ferrocyanide technique to obtain more definitive values for the population of filtering nephrons in the lamprey under conditions of high (in fresh water) and low (in sea water) glomerular filtration rate (GFR) and when the branchial osmotic gradient was eliminated by acute transfer of freshwater lampreys to iso-osmotic brackish water. These studies demonstrated that the renal antidiuresis in lampreys acclimated to full-strength sea water does not involve any reduction in the filtering population of glomeruli. Transfer to brackish water significantly reduced GFR and thereby urine flow rate (287+/−23 ml kg-1 24 h-1 in fresh water; 6.9+/−2.5 ml kg-1 24 h-1 in brackish water). In four of the eight fish examined, 100 % of glomeruli remained filtering; in the other four fish, non-filtering glomeruli occurred in patches along the kidney, always associated with an absence of vascular perfusion, which implies possible endocrine/neural control of vascular tone. The numbers of non-filtering glomeruli were always small, and these glomeruli do not appear to make a major contribution to the overall decline in urine output. The results provide firm evidence that although lampreys, like teleosts, show considerable variations in urine output, the renal mechanisms by which lampreys and the teleosts achieve this differ fundamentally, with glomerular intermittency playing little or no part in the lamprey.


1972 ◽  
Vol 27 (1) ◽  
pp. 75-83 ◽  
Author(s):  
B. J. Potter ◽  
D. J. Walker ◽  
W. W. Forrest

1. A study was made of the changes in electrolyte concentrations and ruminal function which resulted from the provision of 1.3% sodium chloride solutions instead of fresh water to sheep consuming roughage rations in chaffed and in ground pelleted forms.2. Significantly higher osmotic pressures were observed in the rumen fluid of the sheep drinking saline water, the change being especially marked when the ration was ground and pelleted.3. Of the individual electrolytes measured, chloride showed a larger rise in concentration than did sodium plus potassium and it appeared that the sodium and chloride ions in the ingested saline water were differentially removed from the rumen.4. Provision of 1.3% NaCl solution in place of fresh water resulted in greater voluntary intakes of fluid and consequently in greater flows of fluid through the rumen.5. Based upon measurements of deoxyribonucleic acid and polysaccharide, there appeared to be a tendency for the total microbial populations in the rumens of sheep drinking 1.3% NaCl solution to be smaller than for the sheep drinking fresh water.6. The total metabolic activity of the rumen flora, measured calorimetrically, was not appreciably changed when saline water was drunk and the chaffed ration eaten, but was significantly reduced when the ration was ground and pelleted.7. Adaptation of the rumen microflora to high concentrations of NaCl was demonstrated in animals accustomed to drinking 1.3% NaCl solution.


1968 ◽  
Vol 25 (12) ◽  
pp. 2549-2560 ◽  
Author(s):  
D. R. Idler ◽  
B. J. Szeplaki

From the literature there was a doubt as to whether interrenalectomy would result in elevated plasma potassium levels in a elasmobranch; in this study, no elevation was observed by comparison with sham-operated thorny skate (Raja radiata) held in sea water for up to 44 days post-operative.Blood calcium levels were significantly elevated in the interrenalectomized animals between 13 and 23 days but the increase was only 10%.There was no change in osmolality, sodium chloride, magnesium, or urea which can be attributed to interrenalectomy. Noteworthy was the manner in which both sham and interrenalectomized animals were able to maintain plasma electrolyte levels during the long period of starvation after surgery. Whenever significant changes occurred during the course of the experiment, sham and interrenalectomized fish were similarly affected, apart from the exception noted for calcium.Plasma urea levels were significantly depressed after interrenalectomy when the skates were held in a 3:1 mixture of sea water: fresh water for 7–9 days. The same trend was observed for sham-operated animals but the decrease was not significant. Normal animals maintained plasma urea in 75% sea water but not in 60% sea water.


1978 ◽  
Vol 76 (2) ◽  
pp. 347-358 ◽  
Author(s):  
M. M. BABIKER ◽  
J. C. RANKIN

Low doses of arginine-vasotocin (AVT), isotocin and oxytocin (1 pg–1 ng/kg body weight) were antidiuretic in eels adapted to fresh water but not in those adapted to sea-water. High doses (more than 10 ng/kg) were always diuretic. No effects on tubular water reabsorption were observed and the glomerular filtration rate (GFR) was proportional to the maximum reabsorptive rate for glucose (Tm (glucose)) in eels adapted to sea-water. Increases in urinary flow appeared therefore to result from glomerular recruitment. Infusion of AVT or isotocin at low rates reduced the GFR and urinary flow of freshwater eels to the levels found in seawater eels. Vasopressin (lysine or arginine) had no direct effect on kidney function in freshwater eels but blocked both the diuretic and antidiuretic actions of the other hormones. When infused into seawater eels it was diuretic. This effect could have been due to blockade of the actions of endogenous AVT and/or isotocin.


Author(s):  
Н. Демиденко ◽  
N. Demidenko

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.


Author(s):  
Olga Mashukova ◽  
Olga Mashukova ◽  
Yuriy Tokarev ◽  
Yuriy Tokarev ◽  
Nadejda Kopytina ◽  
...  

We studied for the first time luminescence characteristics of the some micromycetes, isolated from the bottom sediments of the Black sea from the 27 m depth. Luminescence parameters were registered at laboratory complex “Svet” using mechanical and chemical stimulations. Fungi cultures of genera Acremonium, Aspergillus, Penicillium were isolated on ChDA medium which served as control. Culture of Penicillium commune gave no light emission with any kind of stimulation. Culture of Acremonium sp. has shown luminescence in the blue – green field of spectrum. Using chemical stimulation by fresh water we registered signals with luminescence energy (to 3.24 ± 0.11)•108 quantum•cm2 and duration up to 4.42 s, which 3 times exceeded analogous magnitudes in a group, stimulated by sea water (p < 0.05). Under chemical stimulation by ethyl alcohol fungi culture luminescence was not observed. Culture of Aspergillus fumigatus possessed the most expressed properties of luminescence. Stimulation by fresh water culture emission with energy of (3.35 ± 0.11)•108 quantum•cm2 and duration up to 4.96 s. Action of ethyl alcohol to culture also stimulated signals, but intensity of light emission was 3–4 times lower than under mechanical stimulation. For sure the given studies will permit not only to evaluate contribution of marine fungi into general bioluminescence of the sea, but as well to determine places of accumulation of opportunistic species in the sea.


2018 ◽  
Vol 3 (2) ◽  
pp. 38-47
Author(s):  
Muhammad Abdul Azis ◽  
Nuryake Fajaryati

This research aims to create a Reosquido desalination tool for evaporation methods using a microcontroller. This tool can control the temperature to speed up the evaporation process in producing fresh water. The method applied to Reosquido desalination uses Evaporation. The first process before evaporation is the detection of temperature in sea water that will be heated using an element heater. The second process of temperature measurement is to turn off and turn on the Arduino Uno controlled heater, when the temperature is less than 80 ° then the heater is on. The third process is evaporation during temperatures between 80 ° to 100 °, evaporation water sticks to the glass roof which is designed by pyramid. Evaporated water that flows into the reservoir is detected by its solubility TDS value. The fourth process is heater off when the temperature is more than 100 °. Based on the results of the testing, the desalination process using a microcontroller controlled heater can speed up the time up to 55% of the previous desalination process tool, namely manual desalination prsoes without using the heater element controlled by the temperature and controlled by a microcontroller which takes 9 hours. Produces fresh water as much as 30ml from 3000ml of sea water, so that it can be compared to 1: 100.


2014 ◽  
Vol 592-594 ◽  
pp. 2409-2415 ◽  
Author(s):  
S. Naga Sarada ◽  
Banoth Hima Bindu ◽  
Sri Rama R. Devi ◽  
Ravi Gugulothu

In recent years with the exacerbation of energy shortage, water crisis increases around the world. With the continuous increase in the level of greenhouse gas emissions, the use of various sources of renewable energy is increasingly becoming important for sustainable development. Due to the rising oil price and environmental regulations, the demand of utilizing alternative power sources increased dramatically. Alternative energy and its applications have been heavily studied for the last decade. Energy and water are essential for mankind that influences the socioeconomic development of any nation. Pure water resources become more and more scarce every day as rivers, lakes wells and even seawater pollution rapidly increases. Solar energy is one promising solution to secure power and potable water to future generation. The process of distillation can be used to obtain fresh water from salty, brackish or contaminated water. Water is available in different forms such as sea water, underground water, surface water and atmospheric water. Clean water is essential for good health. The search for sustainable energy resources has emerged as one of the most significant and universal concerns in the 21st century. Solar energy conversion offers a cost effective alternative to our traditional usages. Solar energy is a promising candidate in many applications. Among the alternative energy sources used for electricity production, wind and solar energy systems have become more attractive in recent years. For areas where electricity was not available, stand alone wind and solar systems have been increasingly used. The shortage of drinking water in many countries throughout the world is a serious problem. Humankind has depended for ages on river, sea water and underground water reservoirs for its fresh water needs. But these sources do not always prove to be useful due to the presence of excessive salinity in the water. To resolve this crisis, different methods of solar desalination have been used in many countries. Distillation is a well known thermal process for water purification, most importantly, water desalination. Most of the conventional water distillation processes are highly energy consuming and require fossil fuels as well as electric power for their operation. Single basin solar still is a popular solar device used for converting available brackish or waste water into potable water. Because of its lower productivity, it is not popularly used. Numbers of works are under taken to improve the productivity and efficiency of the solar still. There are large numbers of PCMs that melt and solidify at wide range of temperatures, making them attractive in a number of applications. PCMs have been widely used in latent heat thermal storage systems for heat pumps, solar engineering and spacecraft thermal control applications. The use of PCMs for heating and cooling applications for buildings has been investigated within the past decade. The experimental results computed in the field of water distillation process using solar energy in the presence of energy storage materials sodium sulphate and sodium acetate are discussed in this paper. Keywords: solar energy, saline water, distillation, phase change material.


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