Amount Of Water Drunk Research Articles

Therapeutic Potential of Duodenal Electrical Stimulation for Obesity: Acute Effects on Gastric Emptying and Water Intake

No satisfactory treatment is available for obesity. Previous animal studies suggested the therapeutic potential of intestinal electrical stimulation for obesity. The aim of this study was to investigate the effects of duodenal electrical stimulation (DES) on gastric emptying and water intake in healthy humans. The study was performed in 12 healthy volunteers intubated with a feeding tube in the duodenum under endoscopy. There were three ring electrodes at the end tip of the tube and the two distal electrodes were used for recording and electrical stimulation. On two separate days, each subject underwent a session of DES with various stimulation parameters, a water-intake test with DES or with sham-DES, and a gastric-emptying test with DES or with sham-DES. DES did not induce any noticeable dyspeptic symptoms. The amount of water drunk by the subjects was significantly reduced from 897 +/- 88 ml with sham-DES to 673 +/- 63 ml with DES (p < 0.002). The mean T(50) of gastric emptying was significantly increased from 113.1 +/- 10.0 min with sham-DES to 176.5 +/- 20.8 min with DES state (p < 0.005). The gastric retention at 2 h was increased with DES (42.8 +/- 4.5% vs 61.4 +/- 4.7%; p < 0.02). DES delays gastric emptying and reduces water intake. It may have a potential application for the treatment of obesity.

Hemodynamic and behavioral effects of angiotensin II in conscious sheep

Intracerebroventricular (ivt) angiotensin II (ANG II) at 0.4, 2, 10, and 50 ng.kg-1.min-1 increased arterial pressure in conscious sheep in a dose-related manner (26 mmHg, P less than 0.05, at 50 ng.kg-1.min-1). Total peripheral resistance (TPR) and right atrial pressure also increased. Heart rate, stroke volume, and cardiac output did not change. Pressor responses to ivt ANG II were not caused by leakage of ANG II into the periphery, because plasma concentrations of ANG II did not change from control (31 +/- 7 pg/ml) at the highest dose of ANG II infused. In contrast, intravenous (iv) ANG II, 10 and 50 ng.kg-1.min-1, increased arterial pressure 29 and 47 mmHg, respectively (P less than 0.05), and decreased heart rate. ANG II, 10 ng.kg-1.min-1 iv, increased plasma ANG II levels from 36 +/- 6 to 354 +/- 69 pg/ml (P less than 0.05). Intracarotid (ic) ANG II, 10 ng.kg-1.min-1, increased arterial pressure 31 mmHg (P less than 0.05) but did not alter heart rate. ANG II ivt caused a dose-related drinking response, with a positive correlation between the amount of water drunk during ivt ANG II infusion and the increase in arterial pressure. Infusions of ANG II at 50 ng.kg-1.min-1 ivt were associated with decreased plasma osmolality and potassium concentration and increased plasma vasopressin concentration.

Water-drinking frequency and quantity of water drunk by steers fed hay or fresh forage

To study the effect of moisture content of the diet on drinking behavior and the amount of water drunk, observations were made on eight Holstein steers fed either fresh cut forage or first cut hay. The observations were made in a barn with a mean temperature of about 13°C. When hay was fed there was no significant day-to-day variation in drinking behavior. With fresh cut forage there were daily variations in moisture concentration and drinking behavior. Drinking occurred mainly within 3 h after feeding for the steers fed hay, while those fed soilage drank casually. Frequency of drinking ( F) was related to the dry matter concentration [DMC (%)] of herbage: F=0.47(±0.09) DMC−6.5, SE=±0.4, r=0.86, P<0.01 Intake of drinking water for each 100 kg of live weight (IDW per 100 kg) for steers fed soilage was related to the dry matter concentration: IDW per 100 kg=0.55(±0.06) DMC−8.7, SE=±0.3, r=0.94,P<0.01 The intake of water in each drinking period for animals fed fresh forage was curvilinearly related to the drinking frequency; for the hay-fed steers there was a negative linear relationship. When the drinking frequency for steers fed the fresh forage increased to the same as that observed for the hay, water intake in each drinking period was the same as found for the hay-fed steers. The frequency of drinking and the amount of water drunk by steers fed fresh forage approached the levels of those fed hay, as the dry matter concentration in soilage approached a certain range lower than that of hay.

An actograph for small laboratory animals controlled by a personal computer.

This system for measuring behavioral activity and for its analysis by personal computer as the recording device of the actograph was developed in order to measure the drinking activity and the feeding activity of small laboratory animals. According to the results of the measurement on male DBA/2J mice with this actograph, 84.0% of the drinking activity occurred in the dark period while 16.0% in the light period, and the amount of water drunk by the mouse was about 5.7 ml/day under the conditions of a 12 hour light period and 12 hour dark period. Under the same conditions, 79.6% of the feeding activity took place in the dark period and 20.4% in the light period. Also there was a positive correlation between both activities.

Polydipsia's Contribution to Temporal Discrimination of Rats on a Fixed Interval Schedule

This experiment concerned the contribution of polydipsia on the temporal discrimination of rats during a fixed-interval 60-sec. schedule. In this study, the timing accuracy of 12 rats which had access to water during training was compared to that of 12 rats which had no water during training. The rats were trained for 25 sessions on an FI 60-sec. schedule. In early sessions before polydipsia was fully developed, no differences existed between the timing accuracy of the water group and no-water group. As the amount of water drunk by the water group increased as the number of sessions increased, a parallel increase was noted in the timing accuracy of the water group. In the final sessions, a significant difference was found between the timing accuracy of rats in the water group and that of those in the no-water group. It was concluded that polydipsia facilitated the development of the temporal discrimination which is characteristic of a fixed-interval 60-sec. schedule.

Plasma prolactin levels and body fluid deficits in the rat: causal interactions and control of water intake.

A study was made of the responses of chronically hyperprolactinaemic rats to selected dipsogenic stimuli. Measurements were also made of the correlation between the state of hydration of the animal and the plasma prolactin levels. After 24 h water deprivation. S.C. isoprenaline (10 micrograms/kg body wt.) or I.P. injection (5 ml/kg body wt.) of a hypertonic solution (50% w/w) of polyethylene glycol (mol. wt 20000) there was no difference between the hyperprolactinaemic and control rats with respect to the total water intake, the time course of drinking or the urine output. After I.V. injection of 2 M-NaCl (5 ml/kg body wt.) there was no difference between the hyperprolactinaemic and control rats with respect to the total water intake or urine output. However, the hyperprolactinaemic rats drank more slowly than the controls. When angiotensin II was infused I.V. at a rate of 0.2 micrograms/min, the water intake was greater and the threshold to drinking lower in the hyperprolactinaemic than control rats. After 24 h water deprivation, plasma prolactin levels rose significantly in both the control and hyperprolactinaemic rats. When the rats were injected I.V. with hypertonic saline (5 ml, 2 M-NaCl/kg body wt.) and denied access to water, plasma prolactin levels had not changed 1 h later in either the control or hyperprolactinaemic animals. It is concluded that there is no interaction either between the plasma osmolality and prolactin secretion or between the plasma prolactin levels and the amount of water drunk in response to intracellular fluid deficits. However, prolactin secretion is stimulated by the combined intra- and extracellular deficits resulting from water deprivation and there is a clearly demonstrated interaction between prolactin and the extracellularly mediated stimulus of angiotensin II.

Deficits in drinking and vasopressin secretion after lesions of the nucleus medianus.

The effects of ablation of the nucleus medianus on drinking and vasopressin secretion were studied in male Long-Evans rats. The amount of water drunk in 1 h was assessed after subcutaneous injection of 5.8% NaCl (13.34 mosm/kg) or of angiotensin II (1.5 mg/kg). In a separate test with no water available, plasma vasopressin was measured 15 min after the above dose hypertonic saline. Ablation of the nucleus medianus, or the dorsal and anterior portions of the nucleus medianus, blocked drinking to hypertonic saline or angiotensin II and attenuated the vasopressin response to hyperosmolality. Animals with septal or diagonal band lesions showed responses comparable to sham-operated rats. These results indicate that a neural pathway important for fluid balance passes through, or terminates in, the nucleus medianus.

Emergence of deprivation-induced drinking: implications for hypothalamically elicited behavior.

The possibility that 23-hr water deprived rats must learn to drink in response to thirst states was examined in subjects presented with consecutive days (CD), alternate days (AD), or no days (ND) of deprivation experience CD animals displayed a gradual rise in water intake; however, motivational factors seemed critical in producing this effect because CD rats drank more and weighed less than the AD animals. In addition, AD subjects always drank more than ND animals; thus, the gradual rise in drinking could not be attributed to an ad lib body water surplus that prevented subjects from being thirsty during the initial drinking session. All subjects were allowed to recover from the first phase of deprivation, and then each group was presented with the consecutive-day deprivation procedure. In this second phase, the groups did not differ in the amount of water drunk; so, learning factors once again were contraindicated because more "practiced" subjects did not ingest more. Habituation processes also were implicated in the gradual increase in drinking. These data contrast with those indicating that rats must "learn" to display consummatory responding during electrical stimulation of the lateral hypothalamus, and they strongly support the possibility that learning-like effects during water deprivation reflect the operation of motivational processes.

The mechanism of drinking induced by parenteral hyperonocotic solutions in the pigeon and in the rat.

1. In pigeons, the I.V. injection of 0.3-1.3 ml. of 50% (w/w) solutions of either polyethylene glycol (mol.wt. 20,000) or dextran (mol.wt. 40,000) induced reliable, rapid dose-dependent drinking responses. The amount of water drunk in response to I.V. polyethylene glycol was greater than that in response to I.P. polyethylene glycol and twice that in response to I.V. dextran. I.V. polyethylene glycol induced a diuresis following the onset of drinking.2. The dipsogenic effect of I.P. polyethylene glycol solutions in the pigeon was depressed by I.V. isotonic NaCl solution 1 hr before offering water but was increased by simultaneous I.V. hyperoncotic polyethylene glycol solution.3. In contrast, in rats, the subcutaneous injection of 25% (w/w) polyethylene glycol (mol.wt. 20,000; 1.25-10.0 ml./kg body wt.) induced reliable drinking responses, while the same doses of polyethylene glycol, injected I.V., did not induce drinking consistently. The volume of water drunk by rats in response to subcutaneous polyethylene glycol was smaller per unit dose than that drunk by I.P. injected pigeons.4. The results suggest that receptors for drinking induced by extracellular dehydration in the pigeon could be situated in the extravascular interstitial section of the extracellular compartment.

The effect of intravenous infusion of angiotensin II on drinking in the Australian marsupial Trichosurus vulpecula

1. When marsupial brush-tailed possums were maintained on a normal fruit and vegetable diet with access to water ad libitum, I.V. infusion of synthetic angiotensin II at rates of 0.035-3.5 mug/kg. min caused short-latency drinking in up to seven of eleven animals tested. These rates also had significant pressor effects.2. There was a positive correlation between the rate of angiotensin infusion and the percentage of tested animals which responded by drinking, as well as the amount of water drunk by such animals. The amount drunk during a second infusion 1 hr later was reduced. There was a negative correlation between the rate of infusion and the latency to drinking.3. Of six animals given access to both water and 1.8% sodium chloride solutions, five drank some saline during maintenance and control periods and all responded with short-latency drinking of water to infusion of angiotensin II at 0.35 mug/kg. min.4. Withdrawal of 10% of blood volume, known to stimulate renin production in the possum, caused an increase in water intake in only one of six possums.5. Infusion of isoprenaline I.V. at 20 mug/kg. min, which caused a profound fall in B.P., had no effect on drinking by all six possums.6. It is concluded that these marsupials share with eutherian mammals responsiveness to a dipsogenic action of angiotensin II, which appears to be inhibited by preceding ingestion of water and potentiated by preceding ingestion of hypertonic saline. The physiological significance of this effect is uncertain.

Lateral preoptic lesions in rats separate urge to drink from amount of water drunk.

Rats with bilaterally symmetrical lesions in the laterla preoptic area do not drink after acute intracellular dehydration, but they drink normally after water deprivation. They, like normal rats, also drink more when cellular dehydration is superimposed upon water deprivation. Unlike normal rats, however, rats with lesions in the lateral preoptic area do not increase their rate of lever-pressing in response to the combined stimulus. Thus, the urge to drink can be separated from the amount of fluid drunk.

Effects of exteriorization of the ureters on the water metabolism of the domestic fowl.

1. Six domestic fowls were operated for exteriorization of the ureters.2. Three weeks after the operation their food and water intake was compared with that of six unoperated control fowls of similar weight.3. Water intake was calculated from the amount of water drunk, the metabolic water and the water content of the food eaten; while water loss was estimated from the water content of urine and faeces excreted and from evaporation.4. Fowls with exteriorized ureters drank more than the control birds. The excess of water drunk by these birds approximated the amount of water lost in the urine.

Dipsogenic effects of intracarotid infusions of various hyperosmolal solutions.

AbstractThirst in response to intracarotid and intravenous infusions (1.5 ml/min) of various hypertonic, equi‐osmolal solutions was studied in the goat. Intracarotid infusions of 1 M NaCl and of 2 M fructose induced conspicuous cumulative drinking. The amount of water drunk during intracarotid infusions of 2 M urea and glycerol was only about a third of that consumed during the corresponding infusions of NaCl and fructose. During intracarotid infusions of 2 M galactose and glucose drinking was inconsistent. Of the intravenous infusions only hypertonic NaCl had a consistent dipsogenic effect. However, the amount of water consumed was considerably smaller and the latency time for drinking much longer than during the intracarotid infusions of NaCI. It is concluded that intracarotid infusions of hypertonic solutions act as considerably stronger thirst stimuli than corresponding intravenous infusions, and that the most pronounced dipsogenic effect is obtained by intracarotid infusions of those hypertonic solutions which also most effectively release antidiuretic hormone in the hydrated goat. The possibility is discussed that intracarotid infusions may stimulate the thirst mechanism indirectly via a rise in the Na+ concentration of the cerebrospinal fluid.

Dissociation of the circadian drinking pattern from eating.

RATS allowed food and water ad lib. show a circadian rhythm of drinking and a close association of water intake with eating. One estimate of the proportion of total water taken at night is 78%1. Meals apparently influence the timing and the amount of water drunk. About 57% of the total drinking occurs within 20 min of meals2. A meal introduces solutes into the blood and shifts water from the body fluids into the gut. To compensate for this, between 1 and 1.5 ml. of water would need to be drunk for each gram of food eaten3. Water requirements over a longer term are also determined by the diet4, because of obligatory renal water losses occasioned by solutes from the food.

The external water exchanges of normal laboratory dogs.

Bitches on a fixed food intake were kept in metabolism cages. Urinary volume, drinking and body weight were measured each day and loss of water by evaporation calculated.The mean evaporative loss of individual dogs varied from 8 to 116 g/kg/day; this could be accounted for by differences in the behaviour of the dogs resulting in different amounts of activity in the cages. Evaporative loss also varied widely from day to day. In direct observations in the laboratory evaporative loss of dogs at rest was about 1 g/kg/hr and this was increased by mild exercise to about 5 g/kg/hr. The environmental conditions were never warm enough to significantly affect evaporative loss.The amount of water drunk by each dog varied from 4 to 109 ml./kg/day; the active dogs with high evaporative loss drank most water, the water intake thus approximately matching evaporative loss. Details of the drinking were recorded by a meter. Much of the drinking occurred during the times of the day when the animals were most active, and consisted of small drinks of 30–100 ml. Water given by stomach tube inhibited drinking for as long as 23 hr. A period of water deprivation increased drinking, usually in the form of large drinks of over 100 ml.The mean urine volume varied in different periods of observation from 80–380 ml./day; the urine was of high concentration, about 1600 m‐osmole/l. The volume was not related to activity of the dogs and varied little from day to day. The main determinant of the volume of the urine appeared to be the rate of excretion of solutes which varied very little because of the fixed daily intake of food. There were only a few days on which the urine was of high volume and dilute; in discussion it is stated that this means that varying release of antidiuretic hormone played little part in determining the urine volume and in the regulation of water balance.A small dose of water (about 5 ml./kg body weight) given by stomach tube always prevented drinking; a larger dose was required to produce water diuresis. This explains why water diuresis rarely occurred in dogs drinking naturally.Water balance was achieved because the evaporative loss due to variable activity was matched by drinking.

A control model of the physiological basis of thirst.

The model presented is basically a servo-regulator containing an input-controlled sampling device and is intended for use as a tool in research on the control of water-intake in rats; a problem in the field of animal motivation. The model incorporates monitoring of the size of the main (extra-cellular and intra-cellular) body-fluid compartments, and proposes that these compartment volumes are the two relevant variables used to regulate the amount of water drunk. It is further argued that sodium chloride intake is controlled using information from the same receptor system. The sampling mechanism of the model accounts for competition among different motivations. Explanations of the interacting relationship between eating and drinking, and between water-intake control and renal control are also included.

Water and food intake and the inhibitory effect of amphetamine on drinking and eating before and after prefrontal lobotomy in dogs.

Summary. A complete section through the forebrain through and just anterior to the orbital sulcus and directed well anterior to the caput of the caudate nucleus was not seen to primarily reduce the water intake of dogs or to cause any reduction in the amount of water drunk by the animals subsequent to the intravenous injection of a certain amount of hypertonic saline. The latter was temporarily the case in one animal where the lesion was extended in ventro‐caudal direction to involve the preoptic area on both sides. Amphetamine (1 mg per kg of body weight) completely inhibited the drinking of water after an intravenous injection of 20 cc of a 20 % NaCl solution in 4 of 5 normal dogs tested. This was no longer the case in 3 of these animals after “prefrontal lobotomy”. An incomplete section through the forebrain in 5 out of 8 dogs made that the dose of amphetamine necessary to inhibit, the food intake of the animals completely had to be increased by 50 to 100 %.

諸種利尿劑, 特に脂肪酸塩類, 尿素及びプリン誘導體の経口的適用による作用比較

Experiments were performed under the normal physiological conditions on a caged rat with free access to water. The diuretic action and the amount of water drunk were compared at regular. intervals after the oral administration of diuretics of various kinds, such as coffein, theocin, urea, potassium chloride, potassium and sodium salts of acetic, succinic and suberic acid. All the experiments were planned statistically and carried out with the method, of uniformity test, and of cross test as, well : as with. Latin square method. First, in the method of uniformity test, 10 mg, 30 mg and 60, mg of. caffein, and, theocin were respectively administered per kg body. weight.but neither diuretic action nor an increase in the amount of water drunk were recognized. Then, 1, 000 mg of urea and 300 mg per kg of potassium chloride were administered. In the case of urea, a remarkable diuretic effect and an increase in the amount of water drunk were recognized. In the case of potassium chloride, temporary diuretic effect was found immediately after its administration and then, the amount of urine gradually decreased and in 5 or 6 days became smaller than before the administration. In the case where 23.5 mg of potassium acetate, 23 mg of potassium succinate and 30 mg of potassium suberate kneaded with a constant amount of wheat flour respectively (each dose is equimolar to the other) were administered, neither diuretic effect nor increase in amount of water drunk was observed, whereas with doses ten times as much as the doses of these compounds respectively, all caused distinct diuretic and increase in the amount of water drunk, although the effect of potassium succinate is less remarkable than those of the other two. Next, the experiments were made by the method of cross test. In this case, too, almost the same distinct diuretic effect and increase in the am ount of water were observed, by using potassium. acetate and potassium usberate. Furthermore, the results obtained by the Latin-square method with those compounds were the same as those of the above-mentioned two methods. When experiments were carried, out in the same, manner as before with their sodium salts instead of potassium salts, suberate showed a slight diuretic effect, while no diuretic action was. recognized in the cases of both acetate and succinate.