Effect Of Restricted Water Intake Research Articles

Restricted Water Intake Adversely Affects Rat Vocal Fold Biology.

A holistic understanding of the many ways that systemic dehydration affects vocal fold biology is still evolving. There are also myriad physiologically relevant methodologies to induce systemic dehydration. To untangle the effects of systemic dehydration on vocal fold biology, we need to utilize realistic, clinically translatable paradigms of systemic dehydration in lab animals. Restricted access to water accommodates clinical translation. We investigated whether systemic dehydration via reduced water intake would negatively affect vocal fold biology. Prospective, in vivo study design. Male Sprague Dawley rats (N = 13) were provided 4 mL/100 g of water/day for 5 days, whereas male control rats (N = 8) were given ad lib access to water. Following euthanasia, tissues were processed for histological staining, gene expression, and protein assays. Renin gene expression level in kidneys increased significantly (P ≤ .05), validating dehydration. Dehydration induced by restricted water access downregulated the gene expression of interleukin-1α and desmoglein-1 (P ≤ .05). Hyaluronidase-2 gene expression increased after dehydration (P ≤ .05). The protein level of desmoglein-1 decreased after dehydration (P ≤ .05). Histological analyses suggested decreased hyaluronan (P ≤ .05) in the water-restricted rat vocal fold. Reduced daily water intake for just 5 days impairs vocal fold biology by disrupting inflammatory cytokine release, reducing plasma membrane integrity, and disrupting the hyaluronan network. This is the first study investigating the dehydrating effects of restricted water intake on vocal fold tissue in an in vivo model. NA (prospective animal study). Laryngoscope, 131:839-845, 2021.

Effects of Restricted Water-Intake on Digestion, Urea Recycling and Renal-Function in Wombats (Marsupialia, Vombatidae) From Contrasting Habitats

Responses to limited water availability were studied in two species of wombats from mesic (Vombatus ursinus) or xeric (Lasiorhinus latifrons) habitats. Four Vombatus and three Lasiorhinus were fed a low-quality straw-based diet containing 0.6% nitrogen and 68% neutral detergent fibre (dry-matter basis). Restriction to 50% of ad libitum intakes of drinking water reduced dry-matter intakes by 30% but did not alter digestibilities of fibre or nitrogen. Nitrogen balances were negative and similar between species and water intakes. Urea pool size (C-14 urea) increased during water restriction but urea-entry rates and the proportion of urea recycled to the gut were similar between water intakes (78-89%). Tritiated water was given to wombats in single intramuscular or intraperitoneal doses. Times to equilibration of tritium in urinary water were large and variable (45 +/- 36 h). Urinary tritium concentrations often declined erratically after equilibration, and were 14 +/- 14% lower than the tritium concentration in the blood. These irregular kinetics for tritiated water suggest that the water-dilution method requires validation for the wombats. Urinary and faecal water losses were reduced by 60% during water restriction. Water was mainly lost in the faeces, which were drier in Lasiorhinus (41 % dry matter) than in Vombatus (31 %). As blood haematocrit and plasma osmolality were similar between water intakes, extracellular spaces were apparently maintained during water restriction. Glomerular filtration rates (creatinine clearance) were low (12 mL min-1) and similar between water intakes. Therefore, a more concentrated urine was produced by tubular resorption in water-restricted wombats. Lasiorhinus had greater urinary osmolalities and urine: plasma ratios of creatinine, which reflected a greater urine-concentrating ability than Vombatus. Apparent water intakes and the ability to reduce urinary and faecal water losses in the wombats are similar to those of kangaroos. The contrasting abilities of Vombatus and Lasiorhinus to minimise both these water losses are directly related to their separate distributions.

Renin, antidiuretic hormone and the kidney in water restriction and rehydration.

1. The effect of restricted water intake followed by voluntary rehydration with water or 10 mM-KCl was studied in four conscious sheep with respect to plasma concentrations of renin, antidiuretic hormone (ADH), protein and electrolytes, and urine flow rate, osmolality and osmolal excretion. 2. Water restriction increased the plasma renin concentration and the plasma ADH concentration. 3. Rehydration with water caused a further rise in plasma renin, but plasma ADH returned to basal levels in less than 2 hr. 4. Rehydration with 10 mM-KCl in order to stabilize plasma K concentration greatly attenuated the post-drinking rise in plasma renin concentration, while plasma ADH levels fell as before. 5. Urine flow rates after rehydration with water and 10 mM-KCl remained low for at least 6 hr in most experiments despite low plasma ADH levels. The effect on urine osmolality ranged from no change to a large drop. 6. The post-drinking antidiuresis was associated with a reduction in solute excretion rate. However, free water clearance usually remained negative. 7. These experiments do not support the existence of a direct nexus between plasma ADH levels and plasma renin concentration.

Effect of restricted water intake during summer on the digestibility of cell-wall constituents, nitrogen retention and water excretion in Marwari sheep

SummaryStudies were made on the effect of 50% reduction in daily water intake during summer on food intake, digestibility coefficients of the cell-wall constituents (CWC), nitrogen retention and water excretion in urine and faeces in the Marwari breed of sheep of the Rajasthan desert, India. The water-restricted animals consumed 54 and 42% less dry matter and digestible energy respectively than normally-watered animals. The digestibility coefficients of different CWC were apparently, though not significantly, higher in water-restricted animals. Throughout the study period, animals of both the groups, particularly the water-restricted group, remained in negative nitrogen balance. Moisture loss through the faeces was about 22% less in the water-restricted group than in the control animals. The water-restricted animals lost 21·1% of body weight in 23 days and these animals, when allowed water ad libitum, were able to recover 71·5 % of the lost body weight within 3 days.

Renin responses to water restriction and rehydration.

1. The effect of restricted water intake and rapid rehydration was studied in three conscious sheep with respect to plasma renin concentration (PRC), blood corticosteroid levels, plasma protein and electrolyte concentrations, and the renal and faecal excretion of sodium and potassium.2. During water restriction the plasma concentrations of renin, protein and sodium rose while aldosterone levels were low or undetectable. Plasma potassium levels were unchanged. External sodium and potassium balance appeared to be unaffected.3. During rehydration the sheep drank more than their estimated water deficit in 3-4 min with the following effects: PRC rose three- to fourfold during the ensuing 12 hr. Aldosterone levels too rose, while plasma protein, sodium and potassium concentrations fell. Urinary sodium excretion virtually ceased for 24 hr, and urine flow rate increased only little during this period.4. If there was a single stimulus to renin release during water restriction and rehydration, it was not an alteration in vascular or extravascular volume, total body sodium, systemic B.P. or plasma sodium concentration.5. It is concluded that the rise in PRC in these experiments is compatible with the theory that altered sodium transport at the macula densa was the stimulus for renin release.

Effect of Restricted Water Intake on Feed Intake, Nutrient Digestibility and Nitrogen Metabolism in Steers

Effect of Restricted Water Intake on Feed Intake, Nutrient Digestibility and Nitrogen Metabolism in Steers

Physiological Comparisons of European and Zebu Steers: II.—Effects of Restricted Water Intake

Restricting the water intake increased significantly the digestibility of the organic matter of the diet in Hereford steers, but the increase in Zebu steers was small and not significant. Changes in the freezing point of rumen contents were possibly due to increased production of saliva when water was restricted, which in turn may have favoured fermentation and consequently digestibility. The freezing points of the contents of the large intestines indicated differences, between the Hereford and Zebu steers, in the absorption of water and osmotically active substances from the terminal gut. Restricting the water intake increased the absorption of water from the large intestine of both types of steer, but changed the freezing point of the contents only in the Herefords.

Effect of Restricted Water Intake on Urine Nitrogen Output in Man on a Low Calorie Diet Devoid of Protein

Effect of Restricted Water Intake on Urine Nitrogen Output in Man on a Low Calorie Diet Devoid of Protein

Effect of restricted water intake on urine nitrogen output in man on a low calorie diet devoid of protein.

Urine nitrogen was measured in three groups of young men receiving, respectively, daily water allowances of 900 ml, 1800 ml and unrestricted quantity. Food was restricted to 1000 Cal. of carbohydrates, 4.5 gm of NaCl and vitamins. The men were required to expend about 120 Cal. daily in walking. The daily urine nitrogen output at the 5th experimental day (adjusted to 70 kg body weight) averaged 9.4 gm for the men on 900 ml of water, 7.1 gm for the men receiving 1800 ml of water and 5.8 gm for the men on water ad libitum. Nitrogen in the feces was unchanged and that in the sweat was either unchanged, or slightly decreased, by water restriction. The increased nitrogen excretion paralleled the degree of dehydration. An elevation of the blood urea nitrogen was observed by the 5th day of combined food and water restriction in the men on 900 ml of water. On rehydration about 3.4 gm of urea nitrogen was washed out, giving rise to a transient continuation of the high urine nitrogen excretion. The increased nitrogen excretion is considered as a metabolic response to the stress of dehydration, partly related to increased activity of the adrenal cortex glands. This catabolic response does not help the body to economize water, as illustrated by the fact that the men receiving the smallest water allowance excreted more urine water than their mates with a more liberal water allowance, at the day of their maximal dehydration. Submitted on December 19, 1956