Physiological mechanisms for thirst in the nonhuman primate

1982 ◽  
Vol 242 (5) ◽  
pp. R423-R428 ◽  
Author(s):  
R. J. Wood ◽  
E. T. Rolls ◽  
B. J. Rolls
Keyword(s):  
Nonhuman Primate ◽  
Rhesus Monkeys ◽  
Water Deprivation ◽  
Isotonic Saline ◽  
Plasma Osmolality ◽  
Physiological Mechanisms ◽  
Cellular Dehydration ◽  
Primary Determinant ◽  
The Relationship ◽  
Intravenous Sodium

The relationship between body fluid deficits and drinking has been investigated in a nonhuman primate. Intravenous sodium chloride infusions (0.93-3.25 M) given to rhesus monkeys caused drinking correlated with increases in plasma osmolality and sodium concentrations. Sucrose infusions (0.3 M in 0.15 M NaCl) also caused drinking while equiosmolal urea infusions did not. It was found that the drinking threshold corresponded to a 2.3% increase in plasma osmolality. Water deprivation for 24 h caused significant cellular dehydration, as indicated by a 5.8% elevation in plasma osmolality that exceeded the threshold for thirst, and a significant hypovolemia as indicated by elevated plasma protein and hematocrit values. Intravenous water preloads decreased plasma osmolality and produced a dose-related decrease in subsequent drinking. Infusions that restored plasma osmolality to predeprivation values, reduced intake by 85%. Intravenous isotonic saline preloads which abolished the hypovolemia did not have a consistent effect and reduced mean water intakes by only 3.2%. Thus in the rhesus monkey, cellular dehydration is an effective stimulus for thirst, and it is the primary determinant of drinking after water deprivation, used as an example of a natural thirst stimulus. In contrast to findings in nonprimates, the extracellular deficit contributes very little to drinking after water deprivation.

Cellular dehydration acutely degrades mood mainly in women: a counterbalanced, crossover trial

2020 ◽  
pp. 1-9
Author(s):  
HyunGyu Suh ◽  
Harris R. Lieberman ◽  
Lisa T. Jansen ◽  
Abigail T. Colburn ◽  
J. D. Adams ◽  
...  
Keyword(s):  
Heat Exposure ◽  
Isotonic Saline ◽  
Plasma Osmolality ◽  
Acute Effect ◽  
Short Version ◽  
Female Age ◽  
Cellular Dehydration ◽  
Total Mood Disturbance ◽  
Control Plasma ◽  
Total Mood Disturbance Score

Abstract It is unclear if mild-to-moderate dehydration independently affects mood without confounders like heat exposure or exercise. This study examined the acute effect of cellular dehydration on mood. Forty-nine adults (55 % female, age 39 (sd 8) years) were assigned to counterbalanced, crossover trials. Intracellular dehydration was induced with 2-h (0·1 ml/kg per min) 3 % hypertonic saline (HYPER) infusion or 0·9 % isotonic saline (ISO) as a control. Plasma osmolality increased in HYPER (pre 285 (sd 3), post 305 (sd 4) mmol/kg; P < 0·05) but remained unchanged in ISO (pre 285 (sd 3), post 288 (sd 3) mmol/kg; P > 0·05). Mood was assessed with the short version of the Profile of Mood States Questionnaire (POMS). The POMS sub-scale (confusion-bewilderment, depression-dejection, fatigue-inertia) increased in HYPER compared with ISO (P < 0·05). Total mood disturbance score (TMD) assessed by POMS increased from 10·3 (sd 0·9) to 16·6 (sd 1·7) in HYPER (P < 0·01), but not in ISO (P > 0·05). When TMD was stratified by sex, the increase in the HYPER trial was significant in females (P < 0·01) but not in males (P > 0·05). Following infusion, thirst and copeptin (surrogate for vasopressin) were also higher in females than in males (21·3 (sd 2·0), 14·1 (sd 1·4) pmol/l; P < 0·01) during HYPER. In conclusion, cellular dehydration acutely degraded specific aspects of mood mainly in women. The mechanisms underlying sex differences may be related to elevated thirst and vasopressin.

Sympathetic neural responses to increased osmolality in humans

2006 ◽  
Vol 291 (5) ◽  
pp. H2181-H2186 ◽  
Author(s):  
William B. Farquhar ◽  
Megan M. Wenner ◽  
Erin P. Delaney ◽  
Allen V. Prettyman ◽  
Michael E. Stillabower
Keyword(s):  
Muscle Sympathetic Nerve Activity ◽  
Isotonic Saline ◽  
Plasma Osmolality ◽  
Plasma Norepinephrine ◽  
Sympathetic Outflow ◽  
Neural Responses ◽  
Burst Frequency ◽  
Norepinephrine Concentration ◽  
The Relationship ◽  
Hypertonic Saline Infusion

The purpose of this study was to examine the relationship between osmolality and efferent sympathetic outflow in humans. We hypothesized that increased plasma osmolality would be associated with increases in directly measured sympathetic outflow. Muscle sympathetic outflow was successfully recorded in eight healthy subjects during a 60-min intravenous hypertonic saline infusion (HSI; 3% NaCl) on one day and during a 60-min intravenous isotonic saline (ISO) infusion (0.9% NaCl) on a different day. The HSI provides an osmotic and volume stimulus, whereas the ISO infusion provides a volume-only stimulus. Muscle sympathetic nerve activity was quantified using the technique of peroneal microneurography. Plasma osmolality increased during the HSI but not during the ISO infusion (ANOVA, P < 0.05). Sympathetic outflow differed between the trials (ANOVA, P < 0.05); during the HSI burst, frequency initially increased from 14.6 ± 2.5 to 18.1 ± 1.9 bursts/min; during the ISO infusion, burst frequency initially declined from 14.7 ± 2.5 to 12.0 ± 2.1 bursts/min. Plasma norepinephrine concentration was greater at the end of the HSI compared with the end of the ISO infusion (HSI: 297 ± 64 vs. ISO: 202 ± 49 pg/ml; ANOVA, P < 0.05). We conclude that HSI-induced increases in plasma osmolality are associated with increases in sympathetic activity in humans.

Increased PGE2 excretion by dDAVP in humans depends on state of hydration

1986 ◽  
Vol 250 (6) ◽  
pp. F1008-F1012 ◽  
Author(s):  
U. Schwertschlag ◽  
J. G. Gerber ◽  
J. S. Barnes ◽  
A. S. Nies
Keyword(s):  
Water Deprivation ◽  
Urine Volume ◽  
Plasma Osmolality ◽  
Urine Osmolality ◽  
Water Diuresis ◽  
Water Load ◽  
Water Ingestion ◽  
Transient Rise ◽  
Relationship Of ◽  
The Relationship

The relationship of renal prostaglandin E2 (PGE2) excretion (UPGEV) to water deprivation, water diuresis, and subsequent antidiuresis by 1-desamino-8-D-arginine vasopressin (dDAVP) was studied in female volunteers. After 16 h of water deprivation, the subjects began a sustained water diuresis for 8 h. This diuresis caused a transient twofold rise in UPGEV at 2 h (P less than 0.05), which then fell back to or below baseline levels. dDAVP given during the water diuresis caused a transient rise of UPGEV as urine volume decreased and plasma osmolality fell from 277 +/- 1.5 to 271 +/- 2 mosmol/kg (P less than 0.01). Another group of subjects had the water diuresis discontinued after 4 h with dDAVP given at the 5th h when urine volume was decreasing and urine osmolality was increasing. In this setting dDAVP did not produce as great a fall in plasma osmolality nor did it increase UPGEV. These data indicate that renal prostaglandin synthesis (as determined by UPGEV) is increased transiently by an acute water load; dDAVP given during continued water ingestion results in a fall in plasma osmolality and increased PGE excretion; however, dDAVP does not increase UPGEV during normal hydration; and UPGEV is independent of changes in urine flow. These findings imply that renal prostaglandins may have a functional role in humans to inhibit the hydroosmotic actions of antidiuretic hormone, and thus hasten the excretion of a water load, and to prevent overhydration when inappropriate antidiuresis occurs. However, there is no evidence that the stimulus for prostaglandin production is dDAVP per se.

scholarly journals Influence of plasma osmolality on baroreflex control of sympathetic activity

2007 ◽  
Vol 293 (4) ◽  
pp. H2313-H2319 ◽  
Author(s):  
Megan M. Wenner ◽  
William C. Rose ◽  
Erin P. Delaney ◽  
Michael E. Stillabower ◽  
William B. Farquhar
Keyword(s):  
Blood Pressure ◽  
Sympathetic Activity ◽  
Isotonic Saline ◽  
Plasma Osmolality ◽  
Saline Infusion ◽  
Sympathetic Outflow ◽  
Intravascular Volume ◽  
Baroreflex Control ◽  
Controlled Breathing ◽  
The Relationship

The purpose of this study was to determine if plasma osmolality alters baroreflex control of sympathetic activity when controlling for a change in intravascular volume; we hypothesized that baroreflex control of sympathetic activity would be greater during a hyperosmotic stimulus compared with an isoosmotic stimulus when intravascular volume expansion was matched. Seven healthy subjects (25 ± 2 yr) completed two intravenous infusions: a hypertonic saline infusion (HSI; 3% NaCl) and, on a separate occasion, an isotonic saline infusion (ISO; 0.9% NaCl), both at a rate of 0.15 ml·kg−1·min−1. To isolate the effect of osmolality, comparisons between HSI and ISO conditions were retrospectively matched based on hematocrit; therefore, baroreflex control of sympathetic outflow was determined at 20 min of a HSI and 40 min of an ISO. Muscle sympathetic outflow (MSNA) was directly measured using the technique of peroneal microneurography; osmolality and blood pressure (Finometer) were assessed. The baroreflex control of sympathetic outflow was estimated by calculating the slope of the relationship between MSNA and diastolic blood pressure during controlled breathing. Plasma osmolality was greater during the HSI compared with the ISO (HSI: 292 ± 0.9 mosmol/kg and ISO: 289 ± 0.8 mosmol/kg, P < 0.05). Hematocrits were matched (HSI: 39.1 ± 1% and ISO: 39.1 ± 1%, P > 0.40); thus, we were successful in isolating osmolality. The baroreflex control of sympathetic outflow was greater during the HSI compared with the ISO (HSI: −8.3 ± 1.2 arbitrary units·beat−1·mmHg−1 vs. ISO: −4.0 ± 0.8 arbitrary units·beat−1·mmHg−1, P = 0.01). In conclusion, when controlling for intravascular volume, increased plasma osmolality enhances baroreflex control of sympathetic activity in humans.

scholarly journals Dehydration followed by sham rehydration contributes to reduced neuronal activation in vasopressinergic supraoptic neurons after water deprivation

2010 ◽  
Vol 299 (5) ◽  
pp. R1232-R1240 ◽  
Author(s):  
W. David Knight ◽  
Lisa L. Ji ◽  
Joel T. Little ◽  
J. Thomas Cunningham
Keyword(s):  
Supraoptic Nucleus ◽  
Water Deprivation ◽  
Isotonic Saline ◽  
Plasma Osmolality ◽  
Inhibitory Interneurons ◽  
Lamina Terminalis ◽  
Fos Expression ◽  
Supraoptic Neurons ◽  
Hypothalamic Activation

This experiment tested the role of oropharyngeal and gastric afferents on hypothalamic activation in dehydrated rats instrumented with gastric fistulas and allowed to drink water or isotonic saline compared with euhydrated controls (CON). Rats were water-deprived for 48 h (48 WD) or 46 h WD with 2 h rehydration with water (46+W) or isotonic saline (46+S). 46+W and 46+S rats were given water with fistulas open (46+WO/46+SO, sham) or closed (46+WC/46+SC). Compared with CON, water deprivation increased and water rehydration decreased plasma osmolality, while sham rehydration had no effect. Water deprivation increased c-Fos staining in the lamina terminalis. However, none of the sham or rehydration treatments normalized c-Fos staining in the lamina terminalis. Analysis of AVP and c-Fos-positive neurons in the supraoptic nucleus (SON) revealed reduced colocalization in 46+WO and 46+SC rats compared with 48 WD and 46+SO rats. However, 46+WO and 46+SC rats had higher c-Fos staining in the SON than 46+WC or CON rats. Examination of c-Fos in the perinuclear zone (PNZ) revealed that sham and rehydrated rats had increased c-Fos staining to CON, while 48 WD and 46+SO rats had little or no c-Fos staining in this region. Thus, preabsorptive reflexes contribute to the regulation of AVP neurons in a manner independent of c-Fos expression in the lamina terminalis. Further, this reflex pathway may include inhibitory interneurons in the PNZ region surrounding the SON.

Osmotic and volaemic regulation of atrial and ventricular natriuretic peptide secretion in conscious eels

1996 ◽  
Vol 149 (3) ◽  
pp. 441-447 ◽  
Author(s):  
H Kaiya ◽  
Y Takei
Keyword(s):  
Natriuretic Peptide ◽  
Blood Volume ◽  
Bolus Injection ◽  
Isotonic Saline ◽  
Plasma Osmolality ◽  
Cellular Dehydration ◽  
Ventral Aorta ◽  
Peptide Secretion ◽  
Osmotic Stimuli ◽  
Ventricular Natriuretic Peptide

Abstract The effects of acute manipulation of plasma osmolality and blood volume on plasma atrial and ventricular natriuretic peptide (ANP and VNP) levels were examined in conscious freshwater eels, Anguilla japonica. A bolus injection of hypertonic NaCl (0·85 m and 1·7 m, 2·5 ml/kg body weight) through a catheter into the ventral aorta produced increases in plasma Na concentration and osmolality with parallel concentration-dependent, transient increases in plasma ANP and VNP levels. Plasma ANP and VNP levels also increased after injection of 1·7 m mannitol solution which produced an increase in plasma osmolality but a decrease in plasma Na concentration. However, injection of a 2·0 m solution of urea, which does not cause cellular dehydration in mammals, produced only small increases in plasma ANP and VNP levels, although plasma osmolality increased. A bolus injection of 10 or 25 ml/kg isotonic saline supplemented with 2% dextran for colloidal osmotic pressure, which theoretically increased blood volume by 29% or 71%, produced volume-dependent, transient increases in plasma ANP and VNP levels without changes in plasma Na concentration and osmolality. Similar volume expansion with dialysed eel plasma caused greater increases than with dextran-saline. However, these increases were much smaller than those after osmotic stimuli. These results indicate that secretion of ANP and VNP is regulated by two receptor mechanisms: osmoreceptors activated by cellular dehydration, not specifically by hypernatraemia, and volume or stretch receptors activated by hypervolaemia. The relative importance of the osmoreceptive mechanism is greater in eels than in mammals where volaemic regulation dominates over osmotic regulation for ANP secretion. Journal of Endocrinology (1996) 149, 441–447

EXPERIMENTAL ASSESSMENT OF THE NANOPARTICLES TOXICITY OF NICKEL OXIDE IN TWO SIZES IN THE SUBCHRONIC EXPERIMENT

2018 ◽  
pp. 30-35
Author(s):  
M.P. Sutunkova ◽  
B.A. Katsnelson ◽  
L.I. Privalova ◽  
S.N. Solovjeva ◽  
V.B. Gurvich ◽  
...  
Keyword(s):  
Nickel Oxide ◽  
Nervous Activity ◽  
Equal Mass ◽  
The Body ◽  
Subchronic Toxicity ◽  
Physiological Mechanisms ◽  
Nickel Oxide Nanoparticles ◽  
The Relationship ◽  
The Brain ◽  
Nanoparticles Toxicity

We conducted a comparative assessment of the nickel oxide nanoparticles toxicity (NiO) of two sizes (11 and 25 nm) according to a number of indicators of the body state after repeated intraperitoneal injections of these particles suspensions. At equal mass doses, NiO nanoparticles have been found to cause various manifestations of systemic subchronic toxicity with a particularly pronounced effect on liver, kidney function, the body’s antioxidant system, lipid metabolism, white and red blood, redox metabolism, spleen damage, and some disorders of nervous activity allegedly related to the possibility of nickel penetration into the brain from the blood. The relationship between the diameter and toxicity of particles is ambiguous, which may be due to differences in toxicokinetics, which is controlled by both physiological mechanisms and direct penetration of nanoparticles through biological barriers and, finally, unequal solubility.

Tolerance and osmotic response to food deprivation and salt loading in the herbivorous non-drinking Moroccan Spiny-tailed lizard Uromastyx nigriventris (Sauria: Agamidae)

2021 ◽  
pp. 1-15
Author(s):  
Bendami Safaa ◽  
Znari Mohammed
Keyword(s):  
Water Deprivation ◽  
Plasma Osmolality ◽  
Condition Index ◽  
Plasma Sodium ◽  
Arid Environments ◽  
Salt Glands ◽  
Salt Loading ◽  
High K ◽  
Short Period ◽  
Herbivorous Species

Abstract Animals inhabiting arid environments use a variety of behavioural and physiological strategies to balance their water and salt budgets. We studied the effects of dehydration and salt loading on osmoregulatory capacities in a large herbivorous desert lizard, the Moroccan Spiny-tailed lizard Uromastyx nigriventris, the family Agamidae. These lizards select plants with a high K+ to Na+ ratio of 15 to 20, and like other herbivorous lizards, effectively eliminate the extra electrolyte load, mainly via a pair of active nasal salt glands, which exude the extra ions from blood. Here we present results of a series of laboratory experiments, which tested a five-week food and water deprivation and the excretory response of nasal salt glands, during a short period of five days, following salt loading by two separated injections of KCl or NaCl at a 5-day interval (4th and 9th days). During food-water deprivation, hypohydrated lizards lost 32% of their initial body mass with a substantial decrease of their Body Condition Index and the tail volume as an index of energy (fat and then potential metabolic water) storage. Plasma osmolality significantly increased by 20%. There were also significantly increased plasma sodium, chloride, and total protein concentrations. On the other hand, there was no significant decrease in the plasma glucose level. Most of the salt loaded lizards secreted far more K+ than Na+ via the nasal glands, even after NaCl loading. The K+/Na+ ratio decreased only after two to three repetitive NaCl injections but insufficient Na+ was eliminated. Two successive KCl injections were successfully eliminated, but daily natural average K+ administration induced progressive hyperkaliemia. These experimental data agreed with previous observations showing variations of plasma Na+ and K+ concentrations in free-living lizards. The nasal gland constitutes the main route of Cl− excretion but the Cl−/(Na+ + K+) ratio may vary according to observations in other herbivorous species.

Cerebral metabolic responses and vasopressin and oxytocin secretions during progressive water deprivation in rats

1992 ◽  
Vol 262 (2) ◽  
pp. R310-R317 ◽  
Author(s):  
M. Kadekaro ◽  
J. Y. Summy-Long ◽  
S. Freeman ◽  
J. S. Harris ◽  
M. L. Terrell ◽  
...  
Keyword(s):  
Water Deprivation ◽  
Glucose Utilization ◽  
Extracellular Volume ◽  
Plasma Osmolality ◽  
Ventrolateral Medulla ◽  
Ang Ii ◽  
Neural Lobe ◽  
Arterial Blood ◽  
Organum Vasculosum Laminae Terminalis ◽  
Enhanced Secretion

Progressive water deprivation increased plasma osmolality, plasma Na+ concentration, and hematocrit in proportion to the severity of dehydration. With increases of 2% in plasma osmolality (24 h dehydration), glucose utilization increased in the supraoptic nuclei and tended to increase in the neural lobe. With further dehydration, glucose utilization also increased in the paraventricular nuclei. These increases were paralleled by depletion of vasopressin and oxytocin contents in the neural lobe and by the enhanced secretion of both hormones into plasma, with a predominant increase of vasopressin. These changes were proportional to the degree of dehydration. With progression of dehydration, decreases in intracellular and extracellular volumes accentuate. Reductions in extracellular volume result in increased angiotensin II (ANG II) formation. Accordingly, glucose utilization in the subfornical organ (SFO), a primary site of ANG II action, increased after 48 and 72 h of dehydration. The median preoptic nucleus, which receives direct inputs from the SFO, also increased glucose utilization at these times. Glucose utilization also increased in the organum vasculosum laminae terminalis, probably in response to the converging inputs from osmoreceptors, volume receptors, and ANG II receptors. Decreases in glucose utilization were observed in the caudal and rostral ventrolateral medulla, perhaps as compensatory responses to decreased extracellular volume to prevent fall in arterial blood pressure.

Relationship between plasma osmolality and plasma vasopressin in human subjects

1980 ◽  
Vol 238 (4) ◽  
pp. E313-E317 ◽  
Author(s):  
M. Hammer ◽  
J. Ladefoged ◽  
K. Olgaard
Keyword(s):  
Linear Models ◽  
Human Subjects ◽  
Plasma Osmolality ◽  
Metabolic Clearance ◽  
Parabolic Model ◽  
Pronounced Increase ◽  
Plasma Vasopressin ◽  
Log Linear ◽  
The Relationship ◽  
Best Fit

The relationship between plasma osmolality (pOsm) and plasma vasopressin (pAVP) was studied in 13 human subjects during dehydration. The fit of linear, log-linear, parabolic, and exponential models was tested. For all of the data, the nonlinear models had the best fit. However, when individual differences in either gain or threshold were allowed for, the linear models were better than log-linear models. Finally, analyses were made with individual data points. Linear models had the best fit in half of the subjects, whereas for the others the parabolic model gave the best fit. For those subjects investigated in the low range of the osmoregulatory curve, a linear relationship was found, whereas, for those having the most pronounced increase in pOsm, the most significant improvement was found with the parabolic model. This finding indicates that the relationship is not stable during dehydration in the whole range and that hypovolemia probably can influence the secretion rate and/or metabolic clearance rate and thereby the relationship.

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