Chloride Regulation at Low Salinities by Nereis Diversicolor (Annelida, Polychaeta)

1970 ◽  
Vol 53 (1) ◽  
pp. 75-92
Author(s):  
RALPH I. SMITH
Keyword(s):  
Electrical Potential ◽  
Urine Volume ◽  
Chloride Concentration ◽  
Pond Water ◽  
The Body ◽  
Salinity Range ◽  
Concentration Gradients ◽  
North Eastern ◽  
Net Uptake ◽  
Chloride Regulation

1. N. diversicolor from estuarine conditions in north-eastern England can be adapted to a chloride concentration in a pond water (PW) medium at least as low as 0.9 mM/l, and shows a net uptake of chloride when returned to a medium 3-10 mM/l more concentrated. But in comparable transfers after adaptation at a chloride concentration of 10 mM/l, net uptake is not measurable. 2. Net uptake of chloride is demonstrable in the lowest salinities, where coelomic chloride concentration drops below the regulatory plateau. Net uptake reaches 3.5 µM/g wet weight/h. 3. Chloride loss is well correlated with weight loss after adaptation in 10 mM/l, but poorly so after adaptation in PW, suggesting that the urine is very hypotonic to body fluid in PW, and isotonic (or less hypotonic) at environmental chloride concentrations of 10 mM/l or higher. 4. Uptake of chloride occurs against both electrical and chemical-concentration gradients over the lower third of the environmental salinity range, which is the range in which hyperosmotic and hyperionic regulation are most pronounced. 5. The electrical potential across the body wall is maximal in PW (17 mV, inside-negative), and decreases to zero in 50 % SW. 6. Chloride influx (as measured with 36Cl) is highest in SW, and decreases in proportion to chloride concentration down to 50-25% SW, rises to a secondary maximum in 10% SW or less, and decreases as fresh water is approached. 7. Urinary chloride loss is low, and proportional to external chloride concentration in higher salinities, maximal in the c. 10% SW range of salinities, and apparently decreases to a minimum in FW. This may be in part the consequence of recovery of chloride from an hypotonic urine, in part the consequence of a reduction in urine volume. Evidence for these last two possibilities will be given in the papers which follow.

scholarly journals Regulation of Water and Some Ions in Gammarids (Amphipoda)

1971 ◽  
Vol 55 (2) ◽  
pp. 357-369
Author(s):  
D. W. SUTCLIFFE
Keyword(s):  
Sodium Chloride ◽  
Sea Water ◽  
Chloride Concentration ◽  
Sodium Concentration ◽  
Body Water ◽  
The Body ◽  
Salinity Range ◽  
Sodium Potassium ◽  
Body Sodium ◽  
Total Body

1. A comparison was made of the body water contents and the concentrations of sodium, potassium and chloride in the blood and body water of Gammarus zaddachi, G. locusta and Marinogammarus finmarchicus. 2. G. zaddachi had a slightly higher body water content than G. locusta and M. finmarchicus. 3. In all three species the blood chloride concentration was lower than the external chloride concentration in 80-113 % sea water, but the blood sodium concentration was equal to or slightly above the sodium concentration in the external medium. 4. The total body sodium concentration was always greater than the total body chloride concentration. In M.finmarchicus the ratio of body sodium/chloride increased from 1.2 to 1.3 over the salinity range 100-20% sea water. In G. zaddachi the ratio of body sodium/chloride increased from 1.08 at 100% sea water to 1.87 in 0.25 mM/l NaCl. 5. The total body potassium concentration remained constant. The potassium loss rate and the balance concentration were relatively high in G. zaddachi. 6. The porportion of body water in the blood space was calculated from the assumption that a Donnan equilibrium exists between chloride and potassium ions in the extracellular blood space and the intracellular space. In G. zaddachi the blood space was equivalent to 60% body H2O at 100% sea water, and equivalent to 50% body H2O at 40% sea water down to 0.5 mM/l NaCl. In M.finmarchicus the blood space was equivalent to 38-44% body H2O at salinities of 20-100% sea water. 7. The mean intracellular concentrations of sodium, potassium and chloride were also calculated. It was concluded that for each ion its intracellular concentration is much the same in the four euryhaline gammarids. The intracellular chloride concentration is roughly proportional to the blood chloride concentration. The intracellular sodium concentration is regulated in the face of large changes in the blood sodium concentration.

Chloride regulation and the function of the coxal glands in ticks

Parasitology ◽  
1946 ◽  
Vol 37 (3-4) ◽  
pp. 172-184 ◽  
Author(s):  
A. D. Lees
Keyword(s):  
Chloride Concentration ◽  
The Body ◽  
High Rate ◽  
Secretory Cells ◽  
Muscle Fibres ◽  
Cellular Origin ◽  
Accessory Glands ◽  
Filtration Membrane ◽  
Small Muscle ◽  
Chloride Regulation

Chloride regulation. Following the ingestion of a blood meal the tick excretes about half the ingested water in the coxal fluid. The mean haemolymph chloride concentration before feeding is 1.00% and after feeding 0.96% NaCl; and that of the coxal fluid, 0.80% NaCl. These results confirm the values given by Boné (1943).Morphology of the coxal glands. These comprise the coxal glands proper, which elaborate the bulk of the coxal fluid, and the smaller accessory glands of unknown function. Each flask-shaped coxal gland consists of two distinct regions, an outer ‘filtration chamber’ and an inner system of tubules. The latter lead to the external opening. The filtration chamber, which communicates with the tubules at only one point, is highly folded into an elaborate series of pockets and fingers which closely invest the tubules; numerous small muscle fibres inserted in these pockets pass outwards from the gland to attachments on the body wall. The histology of the two regions is entirely different: the filtration membrane is only 1–2μ in thickness and its cellular origin is much obscured: the tubule walls are 5–30 μ in thickness, are composed of cells with a dense, deeply staining cytoplasm, and are richly supplied with tracheae. In Ornithodorus delanoei acinus the walls of the sac-like coxal glands are lined both by ‘filtration membrane’ and by large irregular groups of ‘secretory’ cells; there are no true tubules.Function of the coxal glands. The production of coxal fluid is under muscular control. It is believed that the contraction of the coxal gland muscles enlarges the filtration chamber and sets up a sufficient pressure difference across the membrane to initiate filtration into the gland. In the subsequent passage of the fluid down the tubules threshold substances such as chloride are reabsorbed. That the coxal fluid is primarily an ultrafiltrate of the haemolymph is suggested by (a) the rapid passage of dyes and even haemoglobin into the coxal fluid after injection into the haemolymph and (b) the very high rate of liberation of fluid. Serum albumen sometimes passes into the coxal fluid after injection but casein (and the normal haemolymph proteins) are fully retained.

Comparative Study of different Solvent Extract of Plectranthus amboinicus Stem for their Diuretic Activity

2021 ◽  
pp. 4727-4730
Author(s):  
Noor Salma ◽  
Chandra Prakash K ◽  
Syed Sagheer Ahmed ◽  
Saba Tabassum ◽  
Ahalya Devi K H
Keyword(s):  
Acute Toxicity ◽  
Urine Volume ◽  
Chloride Concentration ◽  
The Body ◽  
Toxicity Study ◽  
Fixed Dose ◽  
Diuretic Activity ◽  
Solvent Extract ◽  
Acute Toxicity Study ◽  
Plectranthus Amboinicus

Diuresis can be beneficial in removing toxins from the body. Globally traditional and folklore medicines plays a vital role in health care services. Plectranthus amboinicus belongs to Lamiaceae family is an Indian medicinal plant which has been utilized traditionally to treat various diseases. However, there is no systematic methodology for the use of Plectranthus amboinicus stem as a diuretic. Hence the present study is proposed to evaluate the diuretic activity of various solvent extract of Plectranthus amboinicus stem in the rat model. The acute toxicity study was performed in albino mice by fixed-dose method (OECD guidelines number 425) of CPCSEA. The diuretic activity was carried out using the Lipschitz method. The total urine volume collected in 24hours was observed. Sodium, potassium and chloride concentration in urine were also recorded. The ionic concentrations were recorded calorimetrically. Acute toxicity study proved no toxicity and mortality in any of the animal up to the dose of 2000mg/kg bodyweight. All three extracts of Plectranthus amboinicus have exhibited dose-dependent diuretic activity by increasing urine volume and excreting sodium ions in urine. The urine pH was also elevated. From the study, it can be concluded that the plant Plectranthus amboinicus could be considered as a diuretic agent. This current study encourages the use of this plant in folk medicine. Further study is required for isolation, characterization and formulation of the active constituents responsible for its diuretic activity.

Characterization of Myoelectric Signals Using System Identification Techniques

2004 ◽  
Author(s):  
Jeffrey T. Bingham ◽  
Marco P. Schoen
Keyword(s):  
System Identification ◽  
Motor Neurons ◽  
Current System ◽  
Electrical Potential ◽  
Computer Software ◽  
The Body ◽  
Myoelectric Signals ◽  
Hand Motion ◽  
The Central Nervous System

Human muscle motion is initiated in the central nervous system where a nervous signal travels through the body and the motor neurons excite the muscles to move. These signals, termed myoelectric signals, can be measured on the surface of the skin as an electrical potential. By analyzing these signals it is possible to determine the muscle actions the signals elicit, and thus can be used in manipulating smart prostheses and teleoperation of machinery. Due to the randomness of myoelectric signals, identification of the signals is not complete, therefore the goal of this project is to complete a study of the characterization of one set of hand motions using current system identification methods. The gripping motion of the hand and the corresponding myoelectric signals are measured and the data captured with a personal computer. Using computer software the captured data are processed and finally subjected to several system identification routines. Using this technique it is possible to construct a mathematical model that correlates the myoelectric signals with the matching hand motion.

Studies on the Physiology of Ascaris Lumbricoides

1952 ◽  
Vol 29 (1) ◽  
pp. 22-29
Author(s):  
A. D. HOBSON ◽  
W. STEPHENSON ◽  
A. EDEN
Keyword(s):  
Ascaris Lumbricoides ◽  
Body Fluid ◽  
External Medium ◽  
Chloride Concentration ◽  
The Body ◽  
Considerable Proportion ◽  
Limiting Factor ◽  
Inorganic Cations ◽  
Sodium And Potassium ◽  
Total Concentrations

The results obtained in this investigation are admittedly not as extensive as is desirable but they allow certain conclusions to be drawn. 1. The sodium and potassium contents of the body fluid of Ascaris lumbricoides are somewhat variable, but these variations do not seem to be dependent upon those of the external medium. 2. The calcium and magnesium contents of the body fluid are relatively constant and are not affected by those of the external medium. 3. The chloride concentration of the body fluid is closely related to and always remains lower than that of the external medium. 4. As shown in Table 2, there is a large gap between the total concentrations of inorganic cations and anions in the intestinal fluid of the pig. Presumably a considerable proportion of the inorganic cations are combined with organic anions, at present undetermined. Exposing the worms to saline media composed of chloride caused a large rise in the internal chloride concentration. This may well be a limiting factor in the life of the animals in such media, and the next step forward would seem to be the fuller analysis of the environment to which they are normally exposed.

Finite Element Study of Oxygen Diffusion in the Intervertebral Disc

2000 ◽  
Author(s):  
E. Sélard ◽  
A. Shirazi-Adl ◽  
J. P. G. Urban
Keyword(s):  
Intervertebral Disc ◽  
Blood Supply ◽  
Oxygen Diffusion ◽  
Consumption Rate ◽  
The Body ◽  
Cellular Viability ◽  
Two Dimensional ◽  
Concentration Gradients ◽  
Exchange Area ◽  
The Matrix

Abstract The intervertebral disc consists of a water-rich extra-cellular matrix which is synthesized and maintained by its cells. The disc is the largest avascular tissue in the body with its cells lying as much as 8mm away from the blood supply. Nutrients, essential for maintaining cellular viability, diffuse through the matrix from blood supply under a concentration gradient arising from cellular demand. The oxygen concentration gradients in the intervertebral disc are investigated to examine the effects of exchange area and disc thickness on oxygen flux in the disc. The concentration gradients are computed using the two-dimensional Poisson’s equation and measured values for oxygen consumption rate and oxygen diffusion.

Osmoregulation in the Larva of the Marine Caddis Fly, Philanisus Plebeius (Walk.) (Trichoptera)

1972 ◽  
Vol 57 (3) ◽  
pp. 821-838
Author(s):  
JOHN P. LEADER
Keyword(s):  
Sodium Chloride ◽  
Osmotic Pressure ◽  
Body Surface ◽  
Sea Water ◽  
Electrical Potential ◽  
Chloride Ion ◽  
Chloride Ions ◽  
The Body ◽  
Electrical Potential Difference ◽  
Caddis Fly

1. The larva of Philanisus plebeius is capable of surviving for at least 10 days in external salt concentrations from 90 mM/l sodium chloride (about 15 % sea water) to 900 mM/l sodium chloride (about 150 % sea water). 2. Over this range the osmotic pressure and the sodium and chloride ion concentrations of the haemolymph are strongly regulated. The osmotic pressure of the midgut fluid and rectal fluid is also strongly regulated. 3. The body surface of the larva is highly permeable to water and sodium ions. 4. In sea water the larva is exposed to a large osmotic flow of water outwards across the body surface. This loss is replaced by drinking the medium. 5. The rectal fluid of larvae in sea water, although hyperosmotic to the haemolymph, is hypo-osmotic to the medium, making it necessary to postulate an extra-renal site of salt excretion. 6. Measurements of electrical potential difference across the body wall of the larva suggest that in sea water this tissue actively transports sodium and chloride ions out of the body.

Effects of age and state of incisor dentition on faecal output of dry matter and on faecal and urinary output of nitrogen and minerals, of sheep grazing hill pastures

1974 ◽  
Vol 83 (1) ◽  
pp. 151-160 ◽  
Author(s):  
A. C. Field ◽  
A. R. Sykes ◽  
R. G. Gunn
Keyword(s):  
Body Weight ◽  
Urine Volume ◽  
Late Summer ◽  
The Body ◽  
The Other ◽  
Urinary Output ◽  
Sheep Grazing ◽  
Total N ◽  
P Deficiency ◽  
Daily Intakes

SUMMARYExcretion of D.M., N, Ca, P and Mg in faeces, and N, P and Mg in urine were measured at intervals over 12 months in breeding Scottish Blackface sheep grazing hill pastures. These values were used with data on reproductive performance and body compositional changes, to calculate the energy, nitrogen and mineral balances. The sheep were: 11 6½-year-old with sound mouths (SM), 16 6½-year-old with broken mouths (BM), 16 5½-year-old with all permanent incisors clipped to gum level (CM) and 16 2½-year-old (Y). An energy supplement was given at the end of gestation and during early lactation. All faeces were collected and creatinine was used as an internal marker to estimate urine volume.Faecal D.M. output ranged from 443 to 662 g/day, with highest values in November and lowest in May. Average values for the BM sheep were lower than those for the other groups but when output was expressed as a power function of body weight, the values for the Y sheep were 15% higher than those for the other groups. Faecal excretions of Ca and P in January and February were very low and the values for P were half the expected endogenous faecal loss.Urinary output ofN ranged from 6·0 g/day in February to 22·2 g/day in August and the corresponding urinary urea N: total N ratios were 0·24 and 0·69. Urinary Mg output was highest in late summer and early winter but urinary P showed no consistent trends.The estimated daily intakes of DOM (g) were 936 in November 1969, 599 in January, 414 in February, 1075 in May, 1150 in August and 946 in November 1970.The loss of energy from the body between mating (November) and mid-lactation (June) ranged from 9·5 to 16·8% of the total calculated ME requirements in the Y and BM sheep, respectively. Maintenance requirements averaged 204 kJ/kg body weight/day and the value for the Y sheep was 12% higher than the mean for the older sheep.Nitrogen and mineral balances were calculated for February, May, August and November. The sheep were protein-deficient in winter, not from a shortage of crude protein in the diet but because of its low digestibility (34%). Intakes of Ca and P in winter were low and a real possibility of a P deficiency exists. Estimates of the concentrations of N and of minerals in the herbage consumed by the sheep were made and compared with those obtained for cut herbage from the same pastures. It would appear that the sheep selected herbage of a higher protein content than that of the cut herbage. Herbage selection was greatest in November.

scholarly journals The effects of repeated ingestion of high and low glucose–electrolyte solutions on gastric emptying and blood 2H2O concentration after an overnight fast

2011 ◽  
Vol 106 (11) ◽  
pp. 1732-1739 ◽  
Author(s):  
Gethin H. Evans ◽  
Susan M. Shirreffs ◽  
Ronald J. Maughan
Keyword(s):  
Gastric Emptying ◽  
Urine Volume ◽  
Electrolyte Solutions ◽  
Test Solution ◽  
The Body ◽  
Fluid Restriction ◽  
Fluid Uptake ◽  
Gastric Aspiration ◽  
Low Glucose ◽  
Time Point

The addition of carbohydrate to drinks designed to have a role in rehydrating the body is commonplace. The gastric emptying and fluid uptake characteristics following repeated ingestion of drinks with high and low glucose concentrations were examined in eight subjects (three male and five female). Following a 13 h fluid restriction period, the subjects ingested a volume of test solution amounting to 3 % of the initial body mass over a period of 60 min. Test drinks were 2 and 10 % glucose–electrolyte solutions with osmolalities of 189 (sd 3) and 654 (sd 3) mOsm/kg, respectively. The initial bolus of each test solution contained 10 g of 2H2O. Blood samples were collected throughout drinking and for 60 min afterwards. Gastric volumes were determined via gastric aspiration at 15 min intervals for 120 min. No difference between trials in total stomach volume was observed until 30 min after the ingestion of the first bolus of test drink, but blood 2H concentration was increased during both trials 10 min after ingestion of the first bolus. Blood 2H concentration was greater at this time point during the 2 % glucose trial than during the 10 % glucose trial and remained higher for the duration of the trial with the exception of one time point. Urine volume at the end of the trial was greater in the 2 % glucose trial than in the 10 % glucose trial. It is concluded that the reduced overall rate of fluid uptake following ingestion of the 10 % glucose solution was due largely to a relatively slow rate of gastric emptying.

scholarly journals ELECTROLYTE BALANCE STUDIES IN ADRENALECTOMIZED DOGS WITH PARTICULAR REFERENCE TO THE EXCRETION OF SODIUM

1933 ◽  
Vol 57 (5) ◽  
pp. 775-792 ◽  
Author(s):  
Robert F. Loeb ◽  
Dana W. Atchley ◽  
Ethel M. Benedict ◽  
Jessica Leland
Keyword(s):  
Adrenal Glands ◽  
Urine Volume ◽  
Chloride Ion ◽  
Sodium Concentration ◽  
The Body ◽  
Electrolyte Balance ◽  
Protein Nitrogen ◽  
Water Excretion ◽  
Before And After ◽  
Sodium Metabolism

1. Balance studies have been made on three dogs before and after adrenalectomy, performed in two stages. 2. It has been shown that the sodium concentration of the blood decreases in adrenalectomized dogs, as is true in patients suffering from Addison's disease and in cats experimentally adrenalectomized. 3. There are also decreases in the chloride and bicarbonate concentrations which together are approximately equivalent to the decrease in sodium. 4. An increase in the potassium concentration of the blood occurs after adrenalectomy, as reported in other studies. There is no obvious correlation of this change with changes in potassium balances. 5. The balance studies show a striking loss of sodium from the body during the development of adrenal insufficiency. This loss of Na results from an increased excretion of sodium in the urine and is not complicated by loss of base as a result of vomiting or diarrhea. 6. Following adrenalectomy, both the total amount of sodium and its concentration in the urine are markedly increased. This increase in concentration of sodium occurs in spite of an augmented urine volume. 7. The behavior of the chloride ion following adrenalectomy parallels that of the sodium ion, but the loss is not equivalent. 8. During the period of accumulation of non-protein nitrogen in the blood, the rate of water excretion by the kidney is even greater than before removal of the adrenal glands. 9. The possibility of a regulatory effect of the adrenal glands upon sodium metabolism and renal function has been discussed.

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