Showing papers on "Body water published in 1986"
TL;DR: Sex-specific and group equations predicted D2O-TBW equally well for obese and nonobese subjects and more accurately than weight, height, and/or age.
754 citations
TL;DR: Correcting the formula for measurement of free water excretion allows solute and water intake and excretion to be compared, thereby leading to a better understanding of both the development and correction of disturbances in the plasma sodium level.
206 citations
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01 Jan 1986
TL;DR: The water of the body is distributed into intracellular and extracellular compartments, and the latter may be partitioned into plasma and interstitial fluids.
Abstract: The water of the body is distributed into intracellular and extracellular compartments. The latter may be partitioned into plasma and interstitial fluids.
156 citations
TL;DR: Findings suggest that DHEA acetate treatment affected body weight, body composition and utilization of dietary energy by both impairing fat synthesis and promoting fat-free tissue deposition and resting heat production.
Abstract: Twenty adult Sprague-Dawley outbred rats (10 male and 10 female) were fed a nonpurified diet without or containing dehydroepiandrosterone acetate (DHEA 6 g/kg diet) for 11 w. DHEA-treated animals weighed less than the controls after 6 wk and until the end of treatment. However, only the differences between male groups were statistically significant. Food intake of the DHEA-fed animals was not affected, but resting heat production was elevated for both sexes. Serum triglyceride levels and activity of hepatic glucose-6-phosphate dehydrogenase of the experimental groups were lower than controls. Analyses of body composition indicated DHEA-treated animals had proportionately less body fat and therefore more body water, protein and ash than controls. In most cases, differences in body composition were due primarily to effects of DHEA on the female animals. In a second experiment, DHEA treatment did not alter urinary ketone levels nor did it enhance citrate synthase activity in interscapular brown fat, skeletal muscle, heart or liver. Findings suggest that DHEA acetate treatment affected body weight, body composition and utilization of dietary energy by both impairing fat synthesis and promoting fat-free tissue deposition and resting heat production. Possible mechanisms by which DHEA may affect metabolism are discussed.
111 citations
TL;DR: It is speculated that variations between sodium and free water balance in the sick preterm infant may be responsible for variability in the distribution of postnatal body water losses.
86 citations
01 Jan 1986
TL;DR: In this paper, the anatomy of the fluid spaces in the body, taking into account also the fluid shifts and losses during exercise and their effects on performance, is considered along with the effects of exercise on body water, fluid shifts with exercise, consequences of sweating, dehydration and exercise, heat acclimatization and endurance training, adverse effects of dehydration, thirst and drinking during exercise, stimuli for drinking, and water, electrolyte, and carbohydrate replacement during exercise.
Abstract: It has been found that the performance of the strongest and fittest people will deteriorate rapidly with dehydration. The present paper is concerned with the anatomy of the fluid spaces in the body, taking into account also the fluid shifts and losses during exercise and their effects on performance. Total body water is arbitrarily divided into that contained within cells (cellular) and that located outside the cells (extracellular). The anatomy of body fluid compartments is considered along with the effects of exercise on body water, fluid shifts with exercise, the consequences of sweating, dehydration and exercise, heat acclimatization and endurance training, the adverse effects of dehydration, thirst and drinking during exercise, stimuli for drinking, and water, electrolyte, and carbohydrate replacement during exercise. It is found that the deterioration of physical exercise performance due to dehydration begins when body weight decreases by about 1 percent.
61 citations
TL;DR: The doubly labeled water method was compared with intake-balance for measuring energy expenditure in five patients receiving total parenteral nutrition (TPN) and averaged 3 +/- 6% greater than intake- balance.
57 citations
TL;DR: Results of this study suggest that before using any prediction equation for calculating body composition of cattle in vivo, equations should be tested with a sub-sample of cattle from the population for which its use is intended.
Abstract: Urea dilution equations for prediction of empty body water in live cattle, developed by three separate groups of investigators, were evaluated by comparing empty body water calculated by these equations with that measured chemically in 6-, 12- and 18-mo-old crossbred beef steers (n = 10, 9 and 9, respectively). Of four equations for prediction of percent empty body water, one derived from mixed-breeds of steers overestimated empty body water in the 6-mo-old steers by 7.59% (P less than .05). For the 12- and 18-mo-old steers, calculated and measured percent empty body water did not differ (P greater than .05). Of seven equations for calculation of empty body water volume, two derived from Angus steers with an without live weight in the equation, and one derived from a combination of Angus and mixed-breeds of steers overestimated empty body water (P less than .05) in the 6-mo-old steers. No differences (P greater than .05) between calculated and measured empty body water volume were observed for either the 12- or 18-mo-old steers. When calculated empty body water values were regressed against that measured directly, all regression slopes were not different from 1 (P greater than .05). Intercepts from regressions involving percent empty body water (four equations) were not different from 0. Three of the seven equations for calculation of empty body water volume, one derived from bulls and the others from Angus steers had intercept estimates not different (P greater than .05) from 0. Validity required that these regressions have slopes not different from 1 and intercepts not different from 0. Empty body water calculated from equations that combined live weight and urea space were more highly correlated with directly measured empty body water than that calculated from equations derived only from urea space. Urea space correlations with body composition of our steers also were improved when live weight was included with urea space in multiple regression models. Results of this study suggest that before using any prediction equation for calculating body composition of cattle in vivo, equations should be tested with a sub-sample of cattle from the population for which its use is intended.
45 citations
TL;DR: The TOBEC method is highly suitable for use with human infants and appears to determine body composition as accurately as other available methods.
Abstract: Total body electrical conductivity (TOBEC) has been introduced as a rapid, safe, and noninvasive method suitable for the estimation of fat-free mass. The instrument (EMME or TOBEC) operates on the principle that organisms placed in an electromagnetic field perturb the field to a degree that depends on the amount and volume of distribution of electrolytes present. A study was designed to measure body composition in infants by the TOBEC method and to compare the results with those obtained using the isotope dilution technique. Sixteen infants (age range, 2 days to 9.7 months; weight range, 2 to 8.7 kg) were enrolled. Total body water (TBW) was determined by the isotope dilution technique using H218O. There was a good correlation between the natural logarithm of the TOBEC number and TBW, with a linear correlation coefficient of 0.949. The fat-free body mass of the infants was calculated by TBW (fat-free body mass = /0.082) and by the TOBEC method using the standard previously derived from mature rabbits. TBW measurements by H218O dilution appeared to overestimate fat-free mass which was greater than TBW in five of the 16 infants. Measured by the TOBEC method, fat-free mass ranged from 51 to 91% of total body weight. The TOBEC method is highly suitable for use with human infants and appears to determine body composition as accurately as other available methods.
41 citations
TL;DR: These experiments indicated that PV and ICF were maximally protected, probably to preserve the integrity of the cardiovascular system and to minimize organ injury.
Abstract: We have developed methodology to simultaneously measure fluid redistribution among the major compartments during moderate and severe hypohydration. Total body water (TBW) was determined using tritiated water, extracellular fluid volume (ECF) was measured using a single-injection [14C]inulin technique, and plasma volume (PV) was determined by indocyanine green dye dilution. Moderate (10% decrease in body wt) and severe (15%) hypohydration resulted in significant losses in TBW, ECF, and PV. Plasma volume was decreased by approximately 25% in both groups, and other fluid compartments were differentially affected. For example, the moderately dehydrated group maintained PV by shifting fluid from the interstitial fluid volume (ISF) compartment while preserving the intracellular fluid volume (ICF); conversely, the severely dehydrated group maintained PV by redistributing fluid from both the ISF and ICF compartments. The data indicated that the initial response to fluid loss was the movement of fluid from the ISF pool to sustain both PV and ICF. In severely hypohydrated rats, PV was maintained at the expense of ICF. These experiments indicated that PV and ICF were maximally protected, probably to preserve the integrity of the cardiovascular system and to minimize organ injury.
41 citations
TL;DR: Obese patients with hypertension have an absolute increase in extracellular and interstitial fluid volumes, related both to the degree of overweight and to the mechanisms of hypertension.
Abstract: Fluid volumes and cardiac and renal hemodynamics were investigated in 44 obese men, 22 with normal blood pressure and 22 with sustained essential hypertension. For the same degree of obesity hypertensive patients had a higher value in extracellular (p less than 0.05) and interstitial fluid (p less than 0.01) volumes than normotensive subjects, while plasma volume, total body water, body cellular water, cardiac output, renal blood flow and glomerular filtration rate were similar. For the same level of blood pressure, the expansion of extracellular and interstitial fluid volume paralleled the degree of obesity. Thus, obese patients with hypertension have an absolute increase in extracellular and interstitial fluid volumes. The increase was related both to the degree of overweight and to the mechanisms of hypertension.
TL;DR: By providing an accurate measure of body water, this NMR procedure provides a rapid, noninvasive, reasonably accurate way of estimating body fat content and for estimating the fat content of baboons.
Abstract: A nuclear magnetic resonance (NMR) method is described for quantitatively measuring total body water (TBW) and for estimating the fat content of baboons. The hydrogen associated with water was measured as the amplitude of the free-induction decay voltage following a series of 90 degree radio frequency pulses at the Lamour frequency for hydrogen with a pulse length of 14 microseconds and a peak measuring time of 50 microseconds. TBW was calculated by multiplying the peak amplitude (volts) by the experimentally determined constant for a water standard (g water/V). This NMR method yielded TBW contents similar to those obtained in the same baboons by direct gravimetric procedures. In contrast, the widely used 3H2O-dilution method usually and variably overestimated body water. By providing an accurate measure of body water, this NMR procedure provides a rapid, noninvasive, reasonably accurate way of estimating body fat content.
TL;DR: The findings confirm that total body water can be accurately measured by TOBEC in conditions of abnormal body fluid distribution and do not reflect the intracellular (potassium) space but does predict total water and extracellular (sodium) space.
Abstract: Total body electrical conductivity (TOBEC) provides a rapid and safe noninvasive technique for the assessment of total body water in animals and man. An instrument employing this principle has been shown to measure body water in healthy Sprague-Dawley rats. With the exception of adult obesity in humans, alterations in body fluid compartments that could theoretically affect the utility of conductivity measurements have not been studied. We, therefore, applied the total body electrical conductivity measurement in rats following perturbations of body fluid/electrolyte spaces including obesity, furosemide diuresis, severe burn, and low protein diet. Our findings confirm that total body water can be accurately measured by TOBEC in conditions of abnormal body fluid distribution. However, when the ratio of intracellular to extracellular fluid is significantly reduced, such as the severe burn or low protein intake, TOBEC does not reflect the intracellular (potassium) space but does predict total water and extracellular (sodium) space.
TL;DR: The fall in arterial pressure in obese hypertensives after weight loss may reverse many of the previously mentioned altered findings and underscore previous epidemiological studies that have shown that weight control could be an important measure in the treatment of hypertension.
Abstract: A number of studies have established a close association between increased body mass and elevated blood pressure. The presence of obesity in hypertensive subjects is associated with some hemodynamic, metabolic, and endocrinic characteristics: an increased intravascular volume with a high intracellular body water/interstitial fluid volume ratio, increased cardiac output, stroke volume, and left ventricular work while peripheral resistance was reduced or normal. Weight loss of at least 10 kg can reduce blood pressure independently of changes in sodium intake in obese persons of both sexes with mild, moderate, or severe high blood pressure. The fall in arterial pressure in obese hypertensives after weight loss may reverse many of the previously mentioned altered findings and underscore previous epidemiological studies that have shown that weight control could be an important measure in the treatment of hypertension.
TL;DR: Blood and ultrafiltrate electrical resistivities were continuously monitored during hemofiltration by substituting these values into a previously developed equation that was modified by the authors, the hematocrit value was determined and blood volume change was obtained from the change in this value.
Abstract: Blood and ultrafiltrate electrical resistivities were continuously monitored during hemofiltration. By substituting these values into a previously developed equation that was modified by the authors, the hematocrit value was determined; and blood volume change was obtained from the change in this value. The following facts were discovered as the result of monitoring the blood volume change during treatment: When the body position was changed from the reclining to the sitting position, the blood volume decreased by 4.2 +/- 0.3%. With the body water removal rate kept constant, the body position recumbent, and the subject fasted, the blood volume gradually decreased. However, when the position was changed from reclining to sitting for food intake and once more returned to the supine position after the meal, the blood volume was greatly affected by the change in position and the food intake.
TL;DR: A modest resection of the terminal ileum undertaken during the course of proctocolectomy decreased body weight largely because of a reduction in body fat, and none of the ileostomy patients was found to be dehydrated.
Abstract: Body composition was measured in 24 patients who had previously undergone proctocolectomy and ileostomy. One group (control group) had undergone resection of only small amounts of terminal ileum (median 4 cm), the other group of patients (resected group) had undergone resection of greater lengths of small bowel (median 54 cm). These values of body composition were then compared with predicted values in normal subjects. Proctocolectomy and ileostomy without ileal resection did not significantly affect body weight, or the body contents of fat or water, but led to a reduction in total body nitrogen and total body potassium, suggesting a reduction in fat free mass. A modest resection of the terminal ileum undertaken during the course of proctocolectomy decreased body weight largely because of a reduction in body fat. None of the ileostomy patients was found to be dehydrated.
TL;DR: It is demonstrated that no malnutrition occurs with time in patients adhering to their prescribed diet and the relative validity of the commonly used methods is examined.
TL;DR: This study suggests that both the drugs are likely to be beneficial in ameliorating/prevention of AMS syndrome.
Abstract: Studies were conducted on 29 male healthy subjects having no previous experience of living at high altitude. These subjects were divided into three groups, i.e., subjects treated with placebo, acetazolamide and spironolactone. These subjects were first studied in Delhi. The drug schedule was started 24 hour prior to the airlift of these subjects to an altitude of 3,500 m and was continued for 48 hour after arrival at high altitude. Total body water, extra cellular water, plasma volume, blood electrolytes, pH, pO2, pCO2 and blood viscosity were determined on 3rd and 12th day of their stay at high altitude. Total body water, extra cellular water intracellular water and plasma volume decreased on high altitude exposure. There was a further slight decrease in these compartments with acetazolamide and spironolactone. It was also observed that spironolactone drives out more water from the extracellular compartment. Loss of plasma water was also confirmed by increased plasma osmolality. Increase in arterial blood pH was noticed on hypoxic exposure but the increase was found less in acetazolamide and spironolactone cases. This decrease in pH is expected to result in better oxygen delivery to the tissues at the low oxygen tension. It was also confirmed because blood pO2 increased in both the groups. No significant change in plasma electrolytes was observed in subjects of various groups. Blood viscosity slightly increased on exposure to high altitude. The degree of rise was found less in the group treated with spironolactone. This study suggests that both the drugs are likely to be beneficial in ameliorating/prevention of AMS syndrome.
01 Jan 1986
TL;DR: Body fluid osmolality is normally maintained within narrow bounds through the control of body water balance through the regulation of renal water excretion.
Abstract: Body fluid osmolality is normally maintained within narrow bounds through the control of body water balance. Water intake is regulated to some degree by the thirst mechanism(1) However, the chief means by which body water balance is so precisely maintained is the regulation of renal water excretion.
TL;DR: Urea dilution at 12 min overestimates empty body water only by the volume of urine produced during this time; RRW influences urea dilutions estimation of body composition only as a component of live weight.
Abstract: To determine if urea diffuses into reticulo-ruminal water (RRW) during urea dilution estimation of body composition, four 450-kg heifers were infused intravenously with a solution containing 65.05 g urea plus .95 g 15N-urea, after a 20-h removal of feed. Blood, urine and rumen fluid were collected before infusion and at various times for 120 min after infusion. Plasma 15N clearance was described by a two-pool model. Plasma and urine 15N levels equilibrated within 12 min post-infusion and then declined at similar rates, suggesting that renal clearance is a major component of the second pool. Rumen fluid contained no urea and rumen NH3-N did not increase during the study. Rumen fluid and plasma 15N did not equilibrate over the time studied (rumen fluid 15N/plasma 15N = .07 and .17 at 12 and 120 min after infusion, respectively). Therefore, urea dilution at 12 min overestimates empty body water only by the volume of urine produced during this time; RRW influences urea dilution estimation of body composition only as a component of live weight.
TL;DR: Diet did not affect the equilibration time or the mean retention time of water in the gastrointestinal tract, and compartmental modeling based only upon D2O disappearance from blood did not enable either gut water or rumen water to be accurately estimated.
Abstract: The volume of water in the rumen of four steers was increased (P less than .01) 47% when the level of ground cobs in the diet fed to the steers was changed from 10% to 50%. The difference in gut water content due to diet was not accurately (P greater than .10) estimated by deuterium oxide dilution using either one-, two- or three-compartmental models. Gut water was overestimated and empty body water underestimated when calculated by two-compartment models. The proportions of total body water within each compartment of a three-compartment model were quite variable among steers. When the two-compartment model was solved on the basis of measurements taken from either compartment, different compartment volumes were obtained. This indicated that the two-compartment model did not accurately describe the water equilibration process. Water in the contents of the proximal duodenum and terminal ileum equilibrated with blood in 30 min (range, 10 to 75 min), fecal water equilibrated in 4.3 h (range, 1.7 to 6.7 h) and water in rumen contents equilibrated in 8.3 h (range, 3.8 to 12.5 h). Diet did not affect (P greater than .10) equilibration time or the mean retention time of water in the gastrointestinal tract. Mean retention time was much longer than equilibration time; thus, the equilibration of water in the gastrointestinal tract contents was primarily dependent upon movement of water across the gut mucosa and not upon the flow of water through the gut. One-third of the water in the contents of the gastrointestinal tract was located outside the rumen. Compartmental modeling based only upon D2O disappearance from blood did not enable either gut water or rumen water to be accurately estimated.
01 Sep 1986
TL;DR: The data indicate that the deuterium dilution method provides good estimates of daily fluid intake in young infants, as well as direct measurements of milk intake in 10 exclusively bottle-fed infants recovering from protein-energy malnutrition.
Abstract: The validity of the deuterium dilution technique as a method of measuring fluid intake was investigated by comparing values obtained with this technique and direct measurements of milk intake in 10 exclusively bottle-fed infants recovering from protein-energy malnutrition. Values for total body water were derived from body weight and length using Friis-Hansen's formula. During a 15-d period, average daily milk intake, measured with the deuterium technique, ranged between 519 and 963 ml and was similar to values obtained by direct measurement (range 531-1002 ml). Correlation between both sets of values was highly significant (r = 0.97; P less than 0.001). The data indicate that the deuterium dilution method provides good estimates of daily fluid intake in young infants.
TL;DR: Changes in body weight and body water were significantly affected by dietary fat and protein, but change in dry lean body mass was affected only by level of dietary fat, whereas body nitrogen and fat and lean body energy were not affected bylevel of dietaryfat or protein.
Abstract: Isoenergetic diets formulated at three levels of dietary protein using 12,24 and 40% casein and at two levels of fat using 226 and 1382% corn oil were fed at five levels of intake, ad libitum, 75, 625, 50 and 375% of average ad libitum intake, to 90 lactating rats from d 7 to 14 of lactation Regression equations developed from lactating rats killed on d 7 of lactation were used to calculate initial body composition and energy of rats killed on d 14 of lactation Changes in body weight and body water were significantly (P less than 005) affected by dietary fat and protein, but change in dry lean body mass was affected only by level of dietary fat, whereas body nitrogen and fat and lean body energy were not affected by level of dietary fat or protein However, restricted intake significantly increased loss of all these Likewise, restricted intake decreased milk production Changes in weights of heart and liver were not affected by diet or intake, whereas intestinal weight decreased with intake restriction Liver enzyme activities were markedly affected by intake restriction, whereas responses to dietary protein and fat were marginal
TL;DR: The data suggest that reported increases in plasma solute concentrations in larval amphibians may actually reflect decreases in extracellular fluid volume, rather than increased amounts of solutes, per se.
Abstract: The osmoregulatory responses to warmer temperatures and hormone treatment in cold-adapted (5 degrees C) Rana catesbeiana tadpoles and newly metamorphosed frogs were examined. Tadpoles transferred to 11 degrees C and 18 degrees C and left for 5 days lost 7% and 10% of their body weight. Plasma [Na+] was elevated 28% and 21%, respectively. Control (5 degrees C) animals maintained their body weight and plasma [Na+] constant. Daily treatment with either ovine prolactin (oPRL) or ovine growth hormone (oGH) prevented the weight loss and the increase in extracellular [Na+] that occurred when tadpoles were transferred to 18 degrees C. Neither propylthiouracil (PTU) nor arginine vasotocin (AVT) were effective in countering temperature-induced weight loss in tadpoles. Newly metamorphosed frogs transferred to 18 degrees C also lost weight; this was not prevented by daily treatment with saline, oPRL, oGH or PTU. However, in frogs treated daily with AVT, initial BW was regained by day 6. When warm-adapted (18 degrees C) tadpoles were treated daily for 18 days with saline, bPRL, bGH, thyroxine (T4), ergocornine, cortisol, or cortisol + T4, bPRL was most effective in retarding weight loss and maintaining body water content, whereas T4 + cortisol caused the greatest loss of weight and body water. By day 20, the correlations between weight loss and both body water content and hematocrit were highly significant. These data suggest that reported increases in plasma solute concentrations in larval amphibians may actually reflect decreases in extracellular fluid volume, rather than increased amounts of solutes, per se.
TL;DR: TBW:LBM is not constant but is influenced by body triglyceride content in baboons, which is more than can be expected from the water in the increased adipose tissue mass.
Abstract: Total body water (TBW), lean body mass (LBM), and triglyceride mass were measured in 23 5-yr-old baboons (13 females and 10 males). Male baboons weighed more, had more LBM, more TBW, and contained less triglyceride mass per unit body weight than female baboons. Among all baboons, triglyceride mass per unit body weight ranged from 2.4 to 33.5%. The ratio TBW:LBM ranged from 0.70 to 0.92, increasing (r = 0.98) with increased body triglyceride content (both percent and absolute mass) in both male and female baboons. However, the water content per unit weight of tissues free of fat cells (liver, lungs, kidneys, central nervous system, eyes, tongue) was nearly constant at 0.73 +/- 0.02. The increase in TBW:LBM is more than can be expected from the water in the increased adipose tissue mass. We conclude that TBW:LBM is not constant but is influenced by body triglyceride content in baboons.
TL;DR: Measurements of exchangeable body sodium, total body water and extracellular and intracellular fluid spaces in the animals indicated that fluid and electrolyte changes result largely from dietary protein restriction alone, but these changes only proceed to a condition of visible edema where an excessive or unbalanced intake of sodium and potassium is superimposed upon protein deficiency.
Abstract: The importance of the levels of dietary sodium and potassium in the etiology of gross nutritional edema in a rat model was explored. For this purpose a mineral mixture (EAM) was designed to permit changing the levels of sodium and potassium while maintaining other components of the mixture. The mixture supplied (as % of diet) 0.075 sodium and 0.270 potassium. In study 1 the EAM mixture was found to support adequate growth (approximately 6 g/d) in well-nourished rats. In study 2 the effects of feeding the diet in either agar gel or dry form were explored. The agar gel diet did not aggravate disturbances in body water balance in rats receiving low protein (0.75 and 1.0% lactalbumin) diets for 20 wk. In study 3 the effects of changes in the sodium and potassium content were evaluated with respect to development of edema and body composition. Excessive levels of sodium or potassium (each 493 mg/100 g diet) in the low protein diet (0.5% lactalbumin) increased mortality and the prevalence of gross edema. When dietary sodium and potassium were closer to the estimated requirement for the rat (0.075% and 0.270%, respectively) there was no development of visible edema in protein-restricted rats. Measurements of exchangeable body sodium, total body water and extracellular and intracellular fluid spaces in the animals indicated that fluid and electrolyte changes result largely from dietary protein restriction alone. However, these changes only proceed to a condition of visible edema where an excessive or unbalanced intake of sodium and potassium is superimposed upon protein deficiency.
TL;DR: Evidence is unable to be provided that increases in body fluid volumes contributed to the elevated arterial pressure in this rat model of oral contraceptive hypertension, because these studies were unable to provide evidence.
Abstract: Because estrogens have been reported to produce sodium retention, this study investigated the possibility that hypertension in rats resulting from the ingestion of an estrogen used as an oral contraceptive could be due to increases in body fluid volumes. Female rats were given feed containing mestranol for 1, 3, and 6 mo; control rats were given the feed without mestranol. The mestranol-treated rats had higher arterial pressures than the controls only after 6 mo of treatment. Plasma volume, extracellular fluid volume, and total body water were measured in each rat by the distribution volumes of radioiodinated serum albumin, 35SO4, and tritiated water, respectively. Values for blood volume, interstitial fluid volume, and intracellular fluid volume were derived from these measurements. These body fluid volumes, expressed per 100 g of body weight, were not different between the mestranol-treated rats and their controls at any of the three treatment times. Due to differences in body weight and lean body mass between the mestranol-treated and the control rats, these volumes also were expressed per 100 g of lean body mass. Again, no differences were observed between the mestranol-treated rats and the control rats for any of these body fluid compartments at any of the treatment times. These studies, therefore, were unable to provide evidence that increases in body fluid volumes contributed to the elevated arterial pressure in this rat model of oral contraceptive hypertension.
TL;DR: It is concluded that intrauterine growth retardation in infants who are capable of catching up in growth after birth is the result of a proportional reduction of the daily increments in fetal solids and body water.
Abstract: Total body, extracellular, and intracellular water volume and solids, determined at birth in a group of newborn infants small for date (n = 10) who demonstrated catch-up growth in the first year of life, were compared to similar measurements in newborn infants appropriate for date (n = 11). No significant differences with regard to body water compartment volumes and solids could be found between the 2 groups. It is concluded that intrauterine growth retardation in infants who are capable of catching up in growth after birth is the result of a proportional reduction of the daily increments in fetal solids and body water.
TL;DR: It was concluded that diarrheic neonatal piglets lose body water and dry matter in a ratio similar to that of normal body waterand dry matter concentrations, thus their bodies have normal total body water concentrations and normal average specific heat values.
Abstract: Piglets aged 12 to 72 h in which diarrhea had been induced by enteric Escherichia coli infection or sucrose gavage were studied with respect to body weight, total body water concentration (determined by tritiated-water dilution) and hematocrit. Sucrose-induced diarrhea reduced body weight by 13 to 17%, and E. coli diarrhea, by 8 to 9%. Neither age nor diarrheal treatment affected total body water concentration, although diarrheic piglets tended to have higher hematocrit values at all ages. There was a significant daily cycle in the piglets' hematocrit values, so hematocrit might be a less valid reflector of neonates' whole body hydration status than of adults'. It was concluded that diarrheic neonatal piglets lose body water and dry matter in a ratio similar to that of normal body water and dry matter concentrations, thus their bodies have normal total body water concentrations and normal average specific heat values.
TL;DR: The contribution of extracellular fluid volume (ECFV) to water consumption and plasma vasopressin concentration (PAVP) after water deprivation for 52 h was examined in sheep and reduction of PAVP by NaCl infusion may have been caused by either ISF or intracellular fluidVolume expansion.
Abstract: The contribution of extracellular fluid volume (ECFV) to water consumption and plasma vasopressin concentration (PAVP) after water deprivation for 52 h was examined in sheep. Intravenous infusion of isotonic NaCl, equivalent to either estimated ECFV loss or total body water loss, significantly reduced water intake by 37% when water was offered 3 h after infusion but not when water was offered 1 h after infusion. Plasma osmolality (POsm) was reduced after 3 h. Infusion of 200 mM NaCl, which maintained POsm, decreased water consumption by the same degree as isotonic NaCl infusion. Thus large decreases in POsm had no effect on water intake in this experimental protocol. Lack of inhibition of drinking 1 h after infusion suggests that the decrease observed after 3 h may have been mediated by receptors in the interstitial fluid (ISF) compartment and not the intravascular compartment. PAVP was reduced 3 h after infusion of NaCl but not at 1 or 2 h after infusion. POsm was also decreased at 3 h. Thus reduction of PAVP by NaCl infusion may have been caused by either ISF or intracellular fluid volume expansion.