The Effects of Prolactin and Divalent Ions on the Permeability to Water of Fundulus Kansae

1970 ◽  
Vol 53 (2) ◽  
pp. 317-327 ◽  
Author(s):  
W. T. W. POTTS ◽  
W. R. FLEMING

1. Measurements have been made of the rate of exchange of tritiated water in both intact and hypophysectomized Fundulus kansae in a variety of media. 2. Hypophysectomy reduces the rate of exchange in fresh water. 3. Low doses (30 mu) of ovine prolactin stimulate water turnover in hypophysectomized fish in fresh water. 4. The rate of exchange declines in both intact and hypophysectomized animals with increasing salinity. 5. Experiments with synthetic solutions show that the decline in the rate of exchange in sea water and in higher salinities is due mainly to the effects of calcium ions. 6. Fishes maintained in synthetic sea water containing a low concentration of calcium have both a higher rate of exchange of tritiated water and a higher drinking rate than fish in normal sea water.

1973 ◽  
Vol 58 (1) ◽  
pp. 105-121
Author(s):  
R. KIRSCH ◽  
N. MAYER-GOSTAN

Using isotopic procedures, the drinking rate and chloride exchanges were studied in the eel Anguilla anguilla during transfer from fresh water to sea water. 1. Following transfer to sea water there is a threefold increase of the drinking rate (lasting about 1 h). Then it falls to a minimum after 12-16 h and rises again to a maximum level about the seventh day after the transfer. Then a gradual reduction leads to a steady value which is not significantly different from the one observed in fresh water. 2. The changes with time of the plasma sodium and chloride concentrations are given. Their kinetics are not completely alike. 3. The chloride outflux increases 40-fold on transfer of the eel to sea water, but even so it is very low. After the sixth hour in sea water there is a progressive increase in the flux, so that on the fourth day it is higher (500 µ-equiv. h-1.100 g-1) than in the seawater-adapted animals (230 µ-equiv.h-1.100 g-1). 4. Drinking rate values in adapted animals are discussed in relation to the external medium. The kinetics of the drinking rate together with variations in body weights after freshwater-seawater transfer are discussed in relation to the possible stimulus of the drinking reflex. 5. Chloride fluxes (outflux, net flux, digestive entry) are compared and lead one to assume that in seawater-adapted fish one-third of the chloride influx enters via the gut and two-thirds via the gills.


1967 ◽  
Vol 47 (3) ◽  
pp. 461-470 ◽  
Author(s):  
W. T. W. POTTS ◽  
M. A. FOSTER ◽  
P. P. RUDY ◽  
G. PARRY HOWELLS

1. The total body sodium increases from 45.9 µM/g. fish in fresh water to 59.9 µM/g. fish in 200 % sea water. 2. The rate of exchange of sodium increases from 2 µM/g./hr. in fresh water to 60 µM/g./hr. in 100% sea water. 3. The rate of drinking increases from 0.26%/hr. fresh water to 1.6%/hr. in 400% sea water. Even in 200% sea water drinking accounts for only a quarter of the total sodium influx. 4. The permeability to water, as measured by tritiated water, is highest in fresh water and lowest in 200% sea water. The permeabilities to water measured in this way are consistent with the drinking rates determined in sea water and 200% sea water.


1969 ◽  
Vol 51 (2) ◽  
pp. 529-546 ◽  
Author(s):  
R. MOTAIS ◽  
J. ISAIA ◽  
J. C. RANKIN ◽  
J. MAETZ

1. Cannulation of afferent and efferent branchial vessels in the eel permitted studies of tritiated water clearance. It was observed that most of the diffusional water flow occurs through the gills. 2. Diffusional and osmotic water flows have been measured in a fresh-water (Carassius), a marine (Serranus) stenohaline fish and in two euryhaline species (Platichthys and Anguilla) adapted to either fresh water or sea water, and are found to be lower than in any comparable epithelia so far studied. 3. The diffusional water flow deduced from THO turnover is significantly smaller in the sea-water fish. 4. The osmotic water flow, determined indirectly by measuring drinking rate and urine flow, is smaller in the sea-water fishes despite a greater osmotic gradient across the gills. 5. Attempts to compare diffusional and osmotic permeabilities for the gill are hindered by our ignorance of the extent of solute (salt)-solvent interaction in the epitheium. It is suggested that the gill of the fresh-water-adapted fishes is semi permeable, while that of the sea-water teleosts may not be, because of the very high ionic exchange across the gill. 6. The surprisingly low diffusional and osmotic permeabilities of the gill epithelium in sea-water fish may be possibly related to the absence of water-filled pores.


1969 ◽  
Vol 50 (3) ◽  
pp. 689-703 ◽  
Author(s):  
DAVID H. EVANS

Measurements were made of the flux of tritiated water across various marine, freshwater and euryhaline teleosts. The effects of temperature, body size, species differences, salinity, stress and anaesthetization were studied. 2. The Q10 of the flux of water across teleosts is approximately 1·90 and the flux is related to the 0·88 power of the body weight. 3. All of the freshwater species studied were more permeable to water than the marine species. Euryhaline teleosts appear to have about the same permeability as species to which they are most closely related. 4. While the flounder and the yellow eel are more permeable to water in fresh water than in sea water, the silver eel and the brown trout do not change their permeability and the 3-spined stickleback is less permeable to water in fresh water than in sea water. 5. While stress markedly increases the permeability to water of large brown trout, it has no effect on small brown trout and seems to decrease the water permeability of the plaice. 6. Anaesthetization has no effect on the water permeability of the goldfish but markedly increases the permeability to water of the silver eel. 7. The relationship between the flux of water and either the drinking rate in sea water or the urine flow in fresh water is discussed.


1972 ◽  
Vol 56 (3) ◽  
pp. 703-715
Author(s):  
W. T. W.POTTS ◽  
P. P. RUDY

1. Analyses have been made of the blood and urine of the euryhaline sturgeon Acipenser medirostris and the rates of turnover of sodium and water in both sea water and fresh water have been measured. 2. The blood concentration is rather lower in fresh water than in sea water and the concentration of magnesium ions declines markedly. 3. The rate of turnover of sodium ions is high in sea water and similar to that of marine teleosts. The rate of turnover of sodium is much lower in fresh water but adaptation to fresh water is slow and the animals are more permeable to sodium than are teleosts. 4. The rate of turnover of tritiated water is more rapid in fresh water than in sea water but in each medium it is similar to that of teleosts of a similar size.


1970 ◽  
Vol 21 (6) ◽  
pp. 927 ◽  
Author(s):  
GB Jones ◽  
BJ Potter ◽  
CSW Reid

Tritiated water has been used to compare the water turnover rates and water spaces in sheep which had become accustomed to consuming 1.3 % salt water with those of sheep allowed to drink fresh water. The sheep drinking the saline water (mean body weight 42.0 kg) had mean turnover rates of 207 ml/kg/day compared with 90.3 ml/kg/day for sheep drinking fresh water (mean body weight 38.3 kg). The sheep on salt water revealed a mean tritiated water space of 27.5 kg while that of the sheep on fresh water was 23.5 kg.


1990 ◽  
Vol 152 (1) ◽  
pp. 505-519 ◽  
Author(s):  
PETER GREENAWAY ◽  
H. H. TAYLOR ◽  
S. MORRIS

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.


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.


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