scholarly journals Ionic Regulation and Water Balance in the Aquatic Larva of Sialis Lutaria

1955 ◽  
Vol 32 (2) ◽  
pp. 353-382 ◽  
Author(s):  
J. SHAW

1. The electrolyte composition of the blood, tissues and excretory fluid of the aquatic larvae of Sialis lutaria has been measured, and the regulation of the concentrations of sodium, potassium and chloride in the blood studied in detail. 2. In the normal larvae these ions are not present in the excretory fluid. Potassium and, perhaps, sodium are reabsorbed in the rectum but chloride is never present in the rectum. 3. If these ions are present in the outside medium they are taken into the larvae through the gut. The blood concentration is regulated by the excretion of these ions via the rectal fluid. Potassium is rapidly excreted but chloride tends to be retained in the blood. Sodium is removed more rapidly than chloride. 4. Water enters the larvae by osmosis through the cuticle, but can also be absorbed through the gut by osmosis or together with sodium ions. The water intake is balanced by excretion of rectal fluid. The factors affecting the rate of water excretion have been studied. 5. The larvae are unable to survive in hypertonic saline solutions. This is due to their inability to make good osmotic water loss or to produce a hypertonic excretory fluid.

1993 ◽  
Vol 74 (6) ◽  
pp. 2795-2800 ◽  
Author(s):  
R. Behm ◽  
H. Mewes ◽  
W. H. DeMuinck Keizer ◽  
T. Unger ◽  
R. Rettig

The contribution of peripheral arterial chemoreceptors to cardiovascular and renal responses to acute hypocapnic hypoxia is currently not well understood. We compared the effects of normobaric hypoxia on mean arterial blood pressure (MABP), heart rate, glomerular filtration rate (GFR), renal blood flow (RBF), and renal volume and electrolyte excretion in conscious unilaterally nephrectomized carotid body-denervated (n = 10) and sham-operated (n = 10) control rats. Thirty minutes of normobaric hypoxia (12.5% O2) resulted in significant reductions in arterial PO2 and PCO2 as well as decreases in MABP, GFR, RBF, and renal sodium, potassium, and water excretion. These effects occurred more rapidly and/or were significantly more pronounced in carotid body-denervated than in sham-operated rats. These data indicate that moderate acute hypocapnic hypoxia has profound effects on systemic and renal hemodynamics as well as on renal excretory function in conscious rats. We conclude that stimulation of the peripheral arterial chemoreceptors can partially offset the hypoxia-induced decreases in MABP, RBF, GFR, urine flow, and urinary sodium and potassium excretion, thereby helping to maintain cardiovascular as well as fluid and electrolyte homeostasis.


2020 ◽  
Author(s):  
Philipp Deetjen ◽  
Ulrich Jaschinski ◽  
Axel Heller

Abstract Background: Although intensive care acquired hypernatremia is a common event, limited knowledge exists about the pathogenesis of this disorder. The present study attempts to show that patients undergoing major surgery develop hypernatremia in the presence of both high salt and volume load and concentration disorder of the kidney with insufficient sodium excretion.Methods: In a retrospective study, all patients who were admitted to a 40-bed tertiary surgical intensive care unit of a university hospital from July 2019 to December 2019 with major surgery were examined. Hypernatremia was defined as a sodium value exceeding 145 mmol/l. In addition to the analysis of all patients, complete water and salt balances were performed in a smaller subgroup with 142 patients.Results: 23.9% of patients undergoing major surgery developed hypernatremia, whereby hypernatremia was associated with increased mortality. Patients with hypernatremia showed a renal concentration defect with decreased urine sodium concentration (65 (IQR: 44.8-90) mmol/l vs 78 (IQR: 46-107) mmol/l, p = 0.007) and decreased urine osmolality (514 (IQR: 465-605) mmol/l vs 602 (IQR: 467-740) mmol/l, p < 0.001). In the subgroup of patients with complete sodium and water balance, a positive salt and water balance was observed. After propensity score matching, we found a significantly increased electrolyte free water clearance (1020 ±1740 ml vs -560 ±1620 ml, p <0.001) in the hypernatremia group, together with an inadequately lower total sodium urine excretion (401 ±303 mmol vs 593 ±400 mmol, p = 0.02). Conclusion: The present study shows that postoperative hypernatremia is associated with an imbalance between perioperative salt and water load and renal sodium and water handling with inadequately low renal sodium excretion and inadequately high renal water excretion. The underlying renal concentration disorder may be explained by a defect in a natriuretic-ureotelic response a recently described renal urea-mediated water conservation mechanism after salt exposure.


Telematika ◽  
2017 ◽  
Vol 13 (2) ◽  
pp. 93
Author(s):  
Bambang Yuwono ◽  
Awang Hendrianto Pratomo ◽  
Heru Cahya Rustamaji ◽  
Puji Pratiknyo ◽  
Mochammad Assofa Indera Jati

Water is a basic need for humans and other living things. Various sources of water on this earth has formed a system of close interaction with the components of living things in it. Over the years, water resources have changed in terms of both quality and quantity. This can be due to population growth in addition to the natural changes in nature. The more narrow field of water absorption followed by high water consumption causes the supply of ground water reserves can be threatened. So, we need a mapping and ground water recharge calculations to assist in the monitoring of groundwater reserves.The method used in this research is the Water Balance (keseimbangan air)method. This method is based on any incoming rain water will be equal to the output evapotranspiration and runoff hereinafter this method is applied in the application. Factors affecting groundwater recharge the water balance method is precipitation, evapotranspiration and run off. Information og groundwater recharge is also displayed on the map using Google Map function are related to the database system to produce informative mapsCalculation of groundwater recharge is applied to the daily rainfall data input into the application which then included in the water balance equation method so it can be easy to determine the value of groundwater recharge. Groundwater recharge information can be displayed in the form of mapping, making them easier to understand visually.Based on testing, the highest recharge results of this research on the Kemput station is 1119,5 mm/year with rainfall of 2750 mm/year. Seyegan and Bronggang station is 1026,25 mm/year with rainfall of 2625 mm/year. Angin-angin and Prumpung station is 933 mm/year with rainfall of 2500 mm/year. Beran and Gemawang station is 839.5 mm/year with rainfall of 2375 mm/year. Plataran station is 808.42 mm/year with rainfall of 2333 mm/year. Godean station is 699.5 mm/year with rainfall of 2187 mm/year and the lowest at Tirto Tanjungand Santan stastion 560 mm / year with rainfall of 2000 mm / year.


2017 ◽  
Author(s):  
Richard H Sterns ◽  
Stephen M. Silver ◽  
John K. Hix ◽  
Jonathan W. Bress

Guided by the hypothalamic antidiuretic hormone vasopressin, the kidney’s ability to conserve electrolyte–free water when it is needed and to excrete large volumes of water when there is too much of it normally prevents the serum sodium concentration from straying outside its normal range. The serum sodium concentration determines plasma tonicity and affects cell volume: a low concentration makes cells swell, and a high concentration makes them shrink. An extremely large water intake, impaired water excretion, or both can cause hyponatremia. A combination of too little water intake with too much salt, impaired water conservation, or excess extrarenal water losses will result in hypernatremia. Because sodium does not readily cross the blood-brain barrier, an abnormal serum sodium concentration alters brain water content and composition and can cause serious neurologic complications. Because bone is a reservoir for much of the body’s sodium, prolonged hyponatremia can also result in severe osteoporosis and fractures. An understanding of the physiologic mechanisms that control water balance will help the clinician determine the cause of impaired water conservation or excretion; it will also guide appropriate therapy that can avoid the life-threatening consequences of hyponatremia and hypernatremia.


1960 ◽  
Vol 199 (4) ◽  
pp. 649-652 ◽  
Author(s):  
L. H. Schneyer ◽  
C. A. Schneyer

Inulin, sodium, potassium and chloride levels were determined on serum and submaxillary, parotid and pancreatic glands of inulin-administered nephrectomized rats. Methods of tissue preparation and analysis were examined in some detail. From data obtained, volumes of inulin and electrolyte distribution were calculated. Volumes of distribution in submaxillary, parotid and pancreatic glands, in that order, were, for inulin, 198 ml/kg, 257 ml/kg and 209 ml/kg; for sodium, 232 ml/kg, 318 ml/kg and 275 ml/kg; and, for chloride, 365 ml/kg, 460 ml/kg and 388 ml/kg. Comparison of these values led to the conclusion that intracellular sodium in these glands is possible and that intracellular chloride is likely. Intracellular potassium seems present in concentration similar to that in mammalian muscle. From electrolyte data and levels of amylase in parotid gland and its secretion, it is speculated that parotid secretion could be formed from a small fraction (approx. 10%) derived from unmodified intracellular fluid to which is then added solution having electrolyte composition of extracellular fluid. The closely isotonic secretion of rat parotid gland can thus be predicted without assuming appreciable reabsorption of electrolytes or water.


1976 ◽  
Vol 24 (1) ◽  
pp. 7 ◽  
Author(s):  
PR Baverstock

While Rattus fuscipes survived only 4 days of water deprivation at 21�C, R. norvegicus, R. villosissimus and R. lutreolus survived 13-16 days. There was considerable inter-individual variation in the response of water-deprived R. villosissimus. Analysis of osmotic pressure, urea, sodium, potassium and chloride of both plasma and urine of rats with and without drinking water revealed that: (1) the abilities of R. norvegicus and R. villosissimus to tolerate water deprivation were due in large part to their abilities to produce highly concentrated urine; (2) R. lutreolus tolerated long periods of water deprivation not by urine-concentrating ability but by partly abandoning homeostasis and tolerating elevated levels of plasma solutes; (3) water-deprived R. fuscipes excreted large volumes of concentrated urine, possibly because their relatively high metabolic rate necessitated the excretion of excess metabolites. In all of the rats, urea constituted an unusually low proportion of the total osmotic pressure. The water-balance response of water-deprived rats is at variance with both their macrogeographical distribution and microhabitat preferences.


Water ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 243 ◽  
Author(s):  
Anh Tran ◽  
Joseph Rungee ◽  
Boris Faybishenko ◽  
Baptiste Dafflon ◽  
Susan Hubbard

Evapotranspiration (ET) is a key component of the water balance, which influences hydrometeorology, water resources, carbon and other biogeochemical cycles, and ecosystem diversity. This study aims to investigate the spatio-temporal variations of ET at the East River watershed in Colorado and analyze the factors that control these variations. ET was acquired using the community land model (CLM) simulations and was compared with the values estimated using Fu’s equation and a watershed-scale water balance equation. The simulation results showed that 55% of annual precipitation in the East River is lost to ET, in which 75% of the ET comes from the summer months (May to September). We also found that the contribution of transpiration to the total ET was ~50%, which is much larger than that of soil evaporation (32%) and canopy evaporation (18%). Spatial analysis indicated that the ET is greater at elevations of 2950–3200 m and lower along the river valley (<2750 m) and at the high elevations (>3900 m). A correlation analysis of factors affecting ET showed that the land elevation, air temperature, and vegetation are closely correlated and together they govern the ET spatial variability. The results also suggested that ET in areas with more finely textured soil is slightly larger than regions with coarse-texture soil. This study presents a promising approach to the assessment of ET with a high spatiotemporal resolution over watershed scales and investigates factors controlling ET spatiotemporal variations.


1984 ◽  
Vol 41 (11) ◽  
pp. 1678-1685 ◽  
Author(s):  
Michael A. Giles

Rainbow trout (Salmo gairdneri) were exposed to 3.6 and 6.4 μg Cd/L for periods up to 178 d. Transitory changes in plasma calcium and magnesium were observed in fish exposed to 3.6 μg Cd/L although the differences were not significant. Exposure to 6.4 μg Cd/L, however, resulted in significantly lowered plasma sodium, potassium, calcium, and chloride and elevated magnesium concentrations. Analyses of urine indicated that the rate of urine production, osmolality, and sodium, potassium, chloride, magnesium, calcium, and protein concentrations were unaffected by exposure to 3.6 μg Cd/L although slight changes were observed in the first week of exposure. Urine production rate and urinary concentrations of potassium and chloride were unaffected in trout exposed to 6.4 μg Cd/L but sodium, protein, and osmolality were elevated and calcium and magnesium concentrations reduced in these fish. The results demonstrate that the majority of the cadmium-induced electrolyte imbalances do not result from impairment of renal function.


1954 ◽  
Vol 33 (12) ◽  
pp. 1687-1699 ◽  
Author(s):  
James F. Nickel ◽  
Cheves McC. Smythe ◽  
Emanuel M. Papper ◽  
Stanley E. Bradley

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