VARIATIONS IN THE VOLUME AND CONCENTRATION OF THE BLOOD OF THE SNAIL, HELIX POMATIA L., IN RELATION TO THE WATER CONTENT OF THE BODY

1964 ◽  
Vol 42 (6) ◽  
pp. 1085-1097 ◽  
Author(s):  
R. F. Burton

A convenient measure of the "size" of a snail is its dry weight, exclusive of shell and albumen gland, and, where calculable, its blood solutes. The specimens of Helix pomatia studied contained between 3.8 and 10.2 g of Water per gram dry weight and between 51 and 456 mg of copper per kilogram dry weight. When "copper space" was defined as the weight of blood water that would contain the amount of copper present in the body, copper spaces varied between 1.1 and 4.4 g of water per gram dry weight. Variations in copper space (approximately equal to blood volume) accounted for the greater part of the variation in total body water, though the amount of water in the tissues was also variable. The concentration of sodium in the blood varied naturally over the range 46–129 mmole/kg of water, varying proportionately with chloride. Variations in sodium concentration are largely due to variations in the volume of blood in which the sodium is dissolved, but a given change in blood volume is, in general, associated with a proportionately smaller change in sodium concentration.

1965 ◽  
Vol 43 (5) ◽  
pp. 771-779 ◽  
Author(s):  
R. F. Burton

The water content of the digestive gland, foot, albumen gland, and dart sac of Helix pomatia tends to vary inversely with the concentration of sodium in the blood. That of the albumen gland depends also on size, for, having achieved a dry weight of 0.013 g, the gland continues its growth by the addition of a component containing only about 57% water. This stage is reached when the dry weight of the rest of the snail, less its shell, is about 1.2–1.8 g. The dart sac contains much more potassium than sodium or magnesium and the concentrations of potassium and of magnesium vary inversely with the amount of water in which they are dissolved. The columellar muscle resembles the dart sac in its potassium content (per kilogram dry weight) but contains more water and sodium.


1960 ◽  
Vol XXXIV (II) ◽  
pp. 261-276 ◽  
Author(s):  
Mogens Osler

ABSTRACT The total body water as well as the distribution of water in the extracellular and intracellular compartments was determined in 23 infants born to diabetic mothers (diab. infants) and 15 infants born to normal mothers (normal infants). The total body water was determined by the dilution method using heavy water, and the extracellular water by the dilution method using thiosulphate. Intracellular water was calculated as total water less extracellular water. The analytical methods are described. Diab. infants proved to have a mean total body water of 2.48 litres or 70.2 per cent of the body weight, a mean extracellular water content of 1.41 litre or 38.5 per cent of the body weight, and a mean intracellular water content of 1.16 litre or 31.8 per cent of the body weight. Normal infants had a mean total body water of 2.58 litres or 78.2 per cent of the body weight, a mean extracellular water content of 1.53 litre or 44.9 per cent of the body weight, and a mean intracellular water content of 1.12 litre or 33.5 per cent of the body weight. The reduction in total and extracellular water in the diab. infants is statistically significant, whereas that of intracellular water is more doubtful. The reduction in total body water means that diab. infants are obese. A marked decrease in total as well as extracellular water without a substantial decrease in intracellular water cannot be due to obesity alone, since fat is assumed to contain more extracellular than intracellular water. Increased deposition of glycogen, which binds water in the cells and constitutes an intermediate product in the transformation of glucose to fat, can explain, when also considering the obesity, the reduction in total and extracellular water without a simultaneous decrease of intracellular water. Considering the influence of insulin, corticosteroids and growth hormone on the body composition, the author concludes that the changes found in the body composition of newborn infants of diabetic mothers (obesity + presumably increased glycogen) may be assumed to be due to maternal hyperglycaemia with consequent foetal hyperglycaemia + hyperinsulinism, but not to an action of maternal growth hormone. In other words, the result supports the so-called hyperglycaemia hypothesis as the cause of the increased weight and changed body composition of the newborn infants of diabetic women.


1957 ◽  
Vol 35 (1) ◽  
pp. 631-636 ◽  
Author(s):  
D. G. Baker ◽  
E. A. Sellers

Some aspects of electrolyte metabolism in the rat exposed to a low environmental temperature have been examined. The first day of exposure at 2 °C. was accompanied by a loss of chloride. Continued exposure to cold resulted in a retention of sodium, and to a lesser extent, of potassium. Exposure to cold for 45 days (at 2 °C.) caused a sustained elevation of concentration of sodium in the plasma, with a transient increase in potassium and no change in the chloride concentration. Prolonged exposure to cold resulted in an increased blood volume and total body water content. These observations suggest that the rats acclimatized to cold have a larger proportion of actively metabolizing tissues than do comparable animals at room temperature.


1957 ◽  
Vol 35 (8) ◽  
pp. 631-636 ◽  
Author(s):  
D. G. Baker ◽  
E. A. Sellers

Some aspects of electrolyte metabolism in the rat exposed to a low environmental temperature have been examined. The first day of exposure at 2 °C. was accompanied by a loss of chloride. Continued exposure to cold resulted in a retention of sodium, and to a lesser extent, of potassium. Exposure to cold for 45 days (at 2 °C.) caused a sustained elevation of concentration of sodium in the plasma, with a transient increase in potassium and no change in the chloride concentration. Prolonged exposure to cold resulted in an increased blood volume and total body water content. These observations suggest that the rats acclimatized to cold have a larger proportion of actively metabolizing tissues than do comparable animals at room temperature.


1996 ◽  
Vol 19 (7) ◽  
pp. 411-414 ◽  
Author(s):  
F. Lopot ◽  
P. Kotyk ◽  
J. Bláha ◽  
J. Forejt

A continuous blood volume monitoring (CBVM) device (Inline Diagnostics, Riverdale, USA) was used to study response to prescribed ultrafiltration during haemodialysis (HD) in 66 stabilised HD patients. Fifty percent of patients showed the expected linear decrease in BV right from the beginning of HD (group 1), 32% exhibited no decrease at all (group 2), while eighteen percent formed the transient group 3 which showed a plateau of varying length after which a decrease occurred. The correct setting of dry weight was verified through evaluation of the ratio of extracellular fluid volume to total body water (VEC/TBW) in 26 patients by means of whole body multifrequency impedometry MFI (Xitron Tech., San Diego, USA) and through measurement of the Vena Cava Inferior diameter (VCID) pre and post HD (in 6 and 5 patients from groups 1 and 3 and from group 2, respectively). The mean VEC/TBW in groups 1 and 3 was 0.56 pre and 0.51 post HD as compared to 0.583 and 0.551 in group 2. VCID decreased on average by 14.1% in groups 1 and 3 but remained stable in group 2. Both findings thus confirmed inadequately high estimation of dry weight. Since CBVM is extremely easy to perform it can be used as a method of choice in detecting inadequately high prescribed dry weight. The status of the cardiovascular system must always be considered before final judgement is made.


1970 ◽  
Vol 53 (1) ◽  
pp. 147-163 ◽  
Author(s):  
PETER GREENAWAY

1. Sodium regulation in normal, sodium-depleted and blood-depleted snails has been investigated. 2. Limnaea stagnalis has a sodium uptake mechanism with a high affinity for sodium ions, near maximum influx occurring in external sodium concentrations of 1.5-2 mM-Na/l and half maximum influx at 0.25 mM-Na/l. 3. L. stagnalis can maintain sodium balance in media containing 0.025 mM-Na/l. Adaptation to this concentration is achieved mainly by an increased rate of sodium uptake and a fall of 37 % in blood sodium concentration, but also by a reduction of the sodium loss rate and a decrease in blood volume. 4. A loss of 23% of total body sodium is necessary to stimulate increased sodium uptake. This loss causes near maximal stimulation of the sodium uptake mechanism. 5. An experimentally induced reduction of blood volume in L. stagnalis increases sodium uptake to three times the normal level. 6. About 40% of sodium influx from artificial tap water containing 0.35 mM-Na/l into normal snails is due to an exchange component. Similar exchange components of sodium influx were also observed in sodium-depleted and blood-depleted snails in the same external sodium concentration.


1999 ◽  
Vol 45 (7) ◽  
pp. 1077-1081 ◽  
Author(s):  
Graham Jennings ◽  
Leslie Bluck ◽  
Antony Wright ◽  
Marinos Elia

Abstract Background: The conventional method of measuring total body water by the deuterium isotope dilution method uses gas isotope ratio mass spectrometry (IRMS), which is both expensive and time-consuming. We investigated an alternative method, using Fourier transform infrared spectrophotometry (FTIR), which uses less expensive instrumentation and requires little sample preparation. Method: Total body water measurements in human subjects were made by obtaining plasma, saliva, and urine samples before and after oral dosing with 1.5 mol of deuterium oxide. The enrichments of the body fluids were determined from the FTIR spectra in the range 1800–2800 cm−1, using a novel algorithm for estimation of instrumental response, and by IRMS for comparison. Results: The CV (n = 5) for repeat determinations of deuterium oxide in biological fluids and calibrator solutions (400–1000 μmol/mol) was found to be in the range 0.1–0.9%. The use of the novel algorithm instead of the integration routines supplied with the instrument gave at least a threefold increase in precision, and there was no significant difference between the results obtained with FTIR and those obtained with IRMS. Conclusion: This improved infrared method for measuring deuterium enrichment in plasma and saliva requires no sample preparation, is rapid, and has potential value to the clinician.


Author(s):  
M. P. Horvat ◽  
R. S. Dankovych

The aim of this work was to study the structure of lung and hepatopancreas of Roman snail (Helix of pomatia of L., 1758). The study found that the lung occupies the lower turn of shell and presented by a saccate cavity, in the wall of that there are a kidney and heart with a pericardium, and also a rectum and ureter pass. An external surface of lungs covered by a shell and covered by an epidermis. An internal surface is covered by a flat ciliated epithelium and forms numerous folds in which pulmonary vessels and lacunae are accommodated. The branches of pulmonary vein have a thick muscular wall, that consists of circular and longitudinal muscular layers. An internal surface of lungs covered by the layer of mucus. Inhalation and exhalation are carried out due to reduction and relaxation of muscles of dorsal wall of the body that is named a “diaphragm”. Gas exchange occurs through the hemolymphatic capillaries of the lung wall. Respiratory motions take place not rhythmically, but through the different intervals of time depending on a requirement in oxygen. The frequency of pneumostome closing and opening is typically one time in a minute. At subzero humidity of atmospheric air of pneumostome closed by a mantle, and also one (or a few) epiphragms. The hepatopancreas (“liver” or liver gland) is in the upper rotation of the sink and formed by two parts: right and left, from which two liver ducts enter into the stomach respectively. The liver gland consists of many acinuss, surrounded by connecting tissue, that contains small number of muscular fibres. Calcium cells have a pyramidal form and usually do not reach the lumen of the acinus. Cytoplasm of calcium cells contains inclusions: grains of phosphoricacid lime and drops of fat. The digestive cells of the hepatopencreas are more elongated, often clavicular. Сytoplasm of digestive cells is loose and vacuolated and contain inclusions of yellow-green color. Enzyme cells on histopreparations are difficult to distinguish from digestive ones. They contain transparent vacuoles with a large round inclusion of yellow-green color, which consists of a cluster of several grains of different sizes. Hepatopancreas performs the following functions: secretory (enzyme cells), absorption and intracellular digestion (digestive cells), preservation of nutrients and calcium (calcium cells), and also excretory function.


1969 ◽  
Vol 72 (1) ◽  
pp. 31-40 ◽  
Author(s):  
W. R. McManus ◽  
R. K. Prichard ◽  
Carolyn Baker ◽  
M. V. Petruchenia

SUMMARYThe use of tritiated water to estimate total body-water content of animals experiencing recovery from under-nutrition was studied.The time for equilibration of tritiated water (TOH), given intraperitoneally, with total body water (TBW) was determined in rabbits and in rats. As judged by the specific activity of blood water, equilibration had occurred by 76–125 min in the rabbit and did not appear to be affected by the plane of nutrition. However, between slaughter groups the specific activity of water obtained from the liver 180 min after injection of TOH was significantly different from the specific activity of water simultaneously obtained from the blood plasma. It is concluded that the liver is not a suitable tissue to use for testing achievement of equilibration.As judged by the specific activity of blood water compared to that of water from the whole body macerate, equilibration in mature rats either in stable body condition or undergoing rapid compensatory growth occurred in less than 60 min.A trial comparing TOH-space (corrected by 3% body weight) and actual TBW (by desiccation) was conducted on thirty rabbits which experienced under-nutrition followed by compensatory growth.Prior to under-nutrition the agreement between actual and estimated TBW was satisfactory and within 2·3%. During compensatory growth the agreement was poor— the TOH values over-estimating actual TBW by about 12%.A trial with mature rats confirmed the findings with rabbits. For rats in stable body weight the mean estimated TOH-space for fourteen animals was within 1·2% of the actual TBW. For fourteen rats undergoing compensatory growth the mean estimated TOH-space (corrected by 3% body weight) overestimated actual TBW by 6·2%.


2013 ◽  
Vol 48 (1) ◽  
pp. 109-117 ◽  
Author(s):  
Dejan Reljic ◽  
Eike Hässler ◽  
Joachim Jost ◽  
Birgit Friedmann-Bette

Context Dehydration is assumed to be a major adverse effect associated with rapid loss of body mass for competing in a lower weight class in combat sports. However, the effects of such weight cutting on body fluid balance in a real-life setting are unknown. Objective To examine the effects of 5% or greater loss of body mass within a few days before competition on body water, blood volume, and plasma volume in elite amateur boxers. Design Case-control study. Setting Sports medicine laboratory. Patients or Other Participants Seventeen male boxers (age = 19.2 ± 2.9 years, height = 175.1 ± 7.0 cm, mass = 65.6 ± 9.2 kg) were assigned to the weight-loss group (WLG; n = 10) or the control group (CON; n = 7). Intervention(s) The WLG reduced body mass by restricting fluid and food and inducing excessive sweat loss by adhering to individual methods. The CON participated in their usual precompetition training. Main Outcome Measure(s) During an ordinary training period (t-1), 2 days before competition (t-2), and 1 week after competition (t-3), we performed bioelectrical impedance measurements; calculated total body water, intracellular water, and extracellular water; and estimated total hemoglobin mass (tHbmass), blood volume, and plasma volume by the CO-rebreathing method. Results In the WLG, the loss of body mass (5.6% ± 1.7%) led to decreases in total body water (6.0% ± 0.9%), extracellular water (12.4% ± 7.6%), tHbmass (5.3% ± 3.8%), blood volume (7.6% ± 2.1%; P < .001), and plasma volume (8.6% ± 3.9%). The intracellular water did not change (P > .05). At t-3, total body water, extracellular water, and plasma volume had returned to near baseline values, but tHbmass and blood volume still were less than baseline values (P < .05). In CON, we found no changes (P > .05). Conclusions In a real-life setting, the loss of approximately 6% body mass within 5 days induced hypohydration, which became evident by the decreases in body water and plasma volume. The reduction in tHbmass was a surprising observation that needs further investigation.


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