Effect of inhibition of nitric oxide synthesis on vasopressin secretion in conscious rabbits

1994 ◽  
Vol 266 (2) ◽  
pp. H822-H828 ◽  
Author(s):  
M. Goyer ◽  
H. Bui ◽  
L. Chou ◽  
J. Evans ◽  
L. C. Keil ◽  
...  

NO synthase is present in magnocellular neurons of supraoptic and paraventricular nuclei as well as in the posterior pituitary gland and may participate in control of vasopressin secretion. To test this possibility, experiments were performed in conscious, chronically prepared rabbits to determine the effect of NO synthesis inhibition with NG-nitro-L-arginine methyl ester hydrochloride (L-NAME) on basal vasopressin secretion and vasopressin responses to increased plasma osmolality (hypertonic saline infusion; P osm) and decreased blood pressure (nitroprusside infusion). L-NAME infusion (0.5 mg.kg-1 x min-1 i.v.) increased mean arterial pressure [MAP; 82.6 +/- 3.4 to 93.0 +/- 3.0 mmHg (P < 0.02)], decreased heart rate [HR; 242 +/- 12 to 209 +/- 9 beats/min (P < 0.02)], decreased plasma renin activity [PRA; 3.1 +/- 0.6 to 2.0 +/- 0.6 ng.ml-.2 h-1 (P < 0.001)], and increased plasma vasopressin concentration [P AVP; 2.2 +/- 0.3 to 4.5 +/- 1.0 pg/ml (P < 0.05)]. P(osm) did not change. Hypertonic saline infusion did not change MAP or HR but decreased PRA [4.3 +/- 0.8 to 0.9 +/- 0.2 ng.ml-1 x 2 h-1 (P < 0.01)], increased P(osm) [284 +/- 1 to 305 +/- 2 mosmol/kg H2O (P < 0.001)], and increased PAVP [2.8 +/- 0.3 to 12.7 +/- 2.7 pg/ml (P < 0.01)].(ABSTRACT TRUNCATED AT 250 WORDS)

1995 ◽  
Vol 269 (4) ◽  
pp. R874-R880 ◽  
Author(s):  
A. Takamata ◽  
G. W. Mack ◽  
N. S. Stachenfeld ◽  
E. R. Nadel

We examined the effect of increased body core temperature (Tes) on the plasma arginine vasopressin concentration ([AVP]p) and thirst responses to increased plasma osmolality (Posm) induced by 3% NaCl infusion for 120 min in seven healthy humans. Tes was increased by immersion of the lower legs in 41 degrees C water in a 28 degrees C room (passive heating; HT). Immersion of the lower legs in 34.5 degrees C water on a separate day served as the control (thermoneutral; NT). The 120-min hypertonic saline infusion was initiated 30 min after the onset of leg immersion and was followed by a 30-min rehydration period. Tes in HT increased by 0.21 +/- 0.04 degree C before infusion and by 0.86 +/- 0.08 degree C at the end of infusion. The change in Tes in NT before and after the infusion was negligible. Posm was increased by 15.0 +/- 1.0 mosmol/kgH2O by infusion in both NT and HT. [AVP]p increased by 3.48 +/- 0.72 pg/ml in NT and by 7.59 +/- 1.02 pg/ml in HT. Thus the increase in [AVP]p at a given increase in Posm was markedly higher in HT than in NT. The plasma renin activity response to hypertonic saline infusion in both conditions was similar. Subjective thirst rating and cumulative water intake during rehydration were higher in HT than in NT.(ABSTRACT TRUNCATED AT 250 WORDS)


1980 ◽  
Vol 73 (4) ◽  
pp. 255-260 ◽  
Author(s):  
P H Baylis ◽  
G L Robertson

Hypertonic saline was infused into 11 volunteers to osmotically stimulate vasopressin secretion. A strong positive correlation between plasma arginine vasopressin (PAVP) and plasma osmolality (Pos) was obtained, defined by the function PAVP = 0.63 (Pos – 284), r = +0.80, P < 0.001. The sensitivity of vasopressin secretion to osmotic stimulation was represented by the slope of the expression and the theoretical threshold of vasopressin release by the abscissal intercept. Plasma osmolality at the onset of thirst was 298.5 ± 1.1 mmol/kg. Application of hypertonic saline infusion to 10 polyuric patients clearly separated those with normal osmoregulation of vasopressin secretion from those with cranial diabetes insipidus.


1991 ◽  
Vol 260 (3) ◽  
pp. R533-R539 ◽  
Author(s):  
C. J. Thompson ◽  
P. Selby ◽  
P. H. Baylis

We have studied the reproducibility of the thirst and arginine vasopressin (AVP) responses to osmotic and hypoglycemic stimulation in healthy volunteers undergoing repeat hypertonic (855 mmol/l) saline infusion and insulin tolerance tests (ITTs). Hypertonic saline infusion caused similar mean rises in plasma osmolality, AVP, and thirst on each occasion. Linear-regression analysis defined close relationships between the slopes (r = +0.72, P less than 0.05) and the abscissal intercepts (r = +0.89, P less than 0.001) of the regression lines relating plasma osmolality (Posmol) and plasma AVP (PAVP), and the group intraindividual component of the variance for the slopes and intercepts was 7 and 0.6%, respectively. There were close correlations between the slopes (r = +0.79, P less than 0.02) and the intercepts (r = +0.84, P less than 0.01) of the regression lines relating Posmol and thirst, and group intraindividual component of the variance was 14 and 0.7%, respectively. Hypertonic saline infusion was infused on four occasions in four subjects, and the results showed that the linear regression lines relating PAVP and Posmol and thirst and Posmol were reproducible within an individual. There were similar falls in blood glucose and elevations in PAVP in both ITTs. No relationship was defined between the fall in blood glucose and either the rise in PAVP or the area under the AVP curve (AUC). The intraindividual component of the variance for the rise in AVP and the AUC was 77 and 22.5%, respectively. The AVP and thirst responses to osmotic stimulation are highly reproducible, but there is considerable intraindividual variation in the AVP response to hypoglycemia.


1987 ◽  
Vol 252 (6) ◽  
pp. R1138-R1142 ◽  
Author(s):  
C. J. Thompson ◽  
J. M. Burd ◽  
P. H. Baylis

Drinking rapidly abolishes thirst and vasopressin secretion in dehydrated humans before major changes in plasma osmolality are observed. We studied the effects of drinking on plasma vasopressin and thirst in seven healthy volunteers rendered hypernatremic by the infusion of hypertonic (855 mmol/l) sodium chloride solution. Thirst was measured on a visual analogue scale (0-10 cm). Infusion of hypertonic saline caused linear increases in plasma osmolality (289 +/- 1 to 306 +/- 1 mosmol/kg, mean +/- SE, P less than 0.001), plasma vasopressin (0.6 +/- 0.2 to 6.4 +/- 1.9 pmol/l, P less than 0.001), and thirst (1.4 +/- 0.4 to 7.4 +/- 0.5 cm, P less than 0.001). Water was allowed 15 min after cessation of the infusion, and within 5 min of drinking both plasma vasopressin and thirst were significantly lower than postinfusion. After 20 min of drinking, plasma vasopressin had fallen from 6.5 +/- 0.9 to 1.3 +/- 0.3 pmol/l (P less than 0.001) and thirst from 7.7 +/- 0.5 to 1.0 +/- 0.2 cm (P less than 0.001) despite no significant change in plasma osmolality (306 +/- 0.9 to 304 +/- 0.8 mosmol/kg, P = 0.17), and the drinking of 1,200 +/- 60 ml of water, over 85% of the mean cumulative water intake in the 30-min drinking period. Control studies in the same subjects showed comparable rises in plasma vasopressin, plasma osmolality, and thirst during hypertonic saline infusion but no fall in any of these parameters during an equivalent 30-min period after the infusions, during which water was withheld.(ABSTRACT TRUNCATED AT 250 WORDS)


1986 ◽  
Vol 251 (6) ◽  
pp. R1235-R1239
Author(s):  
H. Raff ◽  
M. M. Skelton ◽  
D. C. Merrill ◽  
A. W. Cowley

We recently reported that ovine corticotropin releasing factor (CRF) infusion in conscious dogs elevated plasma vasopressin. The present study examines the vasopressin, adrenocorticotropic hormone (ACTH), and cortisol responses to CRF infusion (20 ng X kg-1 X min-1), to hypertonic saline infusion (NaCl 0.054 meq X kg-1 X min-1), and to simultaneous coinfusion of CRF and NaCl (CRF + NaCl) without (no-dex) or with (dex-treated) dexamethasone pretreatment in six conscious dogs (6-8 experiments/dog). CRF had no significant effect on plasma sodium or osmolality, blood pressure, or heart rate. NaCl increased plasma sodium from 146 +/- 1 to 151 +/- 1 meq/l and plasma osmolality from 298 +/- 3 to 305 +/- 3 mosmol/kg. Vasopressin increased significantly during CRF (2.1 +/- 0.5 to 4.8 +/- 1.1 pg/ml) and NaCl (1.9 +/- 0.3 to 5.0 +/- 0.8 pg/ml). Coinfusion of CRF and NaCl resulted in a response larger than the sum of the two infusions alone (3.0 +/- 1.6 to 31.4 +/- 18.5 pg/ml). The ACTH response to CRF (45 +/- 8 to 288 +/- 88 pg/ml) was not augmented by coinfusion with NaCl. DEX attenuated the vasopressin and ACTH responses to each infusion. We conclude that CRF-induced increases in vasopressin are augmented by a simultaneous osmotic stimulus. In addition, the plasma vasopressin responses to CRF and/or hypertonic saline infusion are inhibited by glucocorticoid pretreatment.


1985 ◽  
Vol 110 (3) ◽  
pp. 346-351 ◽  
Author(s):  
Simon Smitz ◽  
Jean-Jacques Legros

Abstract. A patient with the chronic hypernatraemia syndrome is described. Using a sensitive and specific radioimmunoassay, the plasma arginine-vasopressin (AVP) level was measured under various conditions. With an unrestricted diet, the plasma AVP level was inappropriately low for the degree of plasma hyperosmolality (0.9 pmol/l and 302 mOsm/kg, respectively). After chronic water loading, plasma osmolality was 271 mOsm/kg, plasma AVP level 1.5 pmol/l, and the urine remained hypertonic with respect to the plasma. During hypertonic saline infusion, plasma osmolality increased from 271 to 294 mOsm/kg without a concomitant increase in the plasma AVP concentration. After sc injection of apomorphine and after haemodynamic stimulation, the plasma AVP concentration increased from 0.8 to 36 pmol/l and from 1.2 to 6.3 pmol/I, respectively. These data demonstrate a selective deficiency in the osmoregulation of the AVP secretion. The observed neuroendocrine abnormalities may be linked to a congenital malformation of the brain.


2019 ◽  
Vol 3 (Supplement_1) ◽  
Author(s):  
HyunGyu Suh ◽  
Harris Lieberman ◽  
Lisa Jansen ◽  
J D Adams ◽  
Adam Seal ◽  
...  

Abstract Objectives Mild and moderate dehydration adversely affect mood and cognitive function. During dehydration, hypertonic hypovolemia activates both osmo- and baro-receptors but it is not known which physiological pathway is associated with degraded mood state. This study examined the acute effect of osmoreceptor stimulation on mood. Methods Sixty healthy adults (50% females, 30 ± 1 y; BMI: 26.9 ± 4.0 kg·m−2) were infused intravenously with 3.0% (HYPER) or 0.9% (ISO) NaCl for 2 h (0.1 ml·kg−1·min−1) using a counterbalanced, crossover design. Blood samples were collected every 30 minutes to measure plasma osmolality (POsm), copeptin (a surrogate marker of vasopressin), and renin-angiotensin-aldosterone system (RAAS) hormones. Mood was assessed with the short version of Profile of Mood State (POMS) questionnaire before and after the infusion. Results POsm and copeptin increased from 286 ± 3 mmol·kg−1 to 305 ± 4 mmol·kg−1 and from 4.5 ± 3.7 pmol·L−1 to 20.4 ± 12.8 pmol·L−1, respectively in HYPER (P < 0.05), and were unchanged in ISO (P > 0.05). No hormonal differences were observed between trials for RAAS hormones (P > 0.05). During HYPER copeptin, following the 2-h infusion, was greater in females than in males (female: 23.4 ± 13.9 pmol·L−1, male: 17.4 ± 10.9 pmol·L−1; P < 0.05). The POMS total mood disturbance (TMD) score increased from 10.5 ± 0.9 to 16.5 ± 1.6 in HYPER (P < 0.05), but not in ISO (P > 0.05). Among POMS subscales, depression-dejection and fatigue-inertia increased in HYPER compared to ISO (P < 0.05). When TMD responses in the HYPER trial were analyzed with sex as a between-subjects factor, the increase was significant in females (pre: 10.2 ± 1.0, post: 18.6 ± 2.3; P < 0.001) but not in males (pre: 10.8 ± 1.4, post: 14.0 ± 2.0; P > 0.05). The confusion-bewilderment subscales and fatigue-inertia of the POMS were also elevated post HYPER in females (P < 0.05), but not in ISO (P > 0.05) in either sex. Conclusions Hypertonic saline infusion acutely degrades mood state, and women appear to have a more pronounced response. The underlying mechanisms remain to be determined but may be related to higher copeptin levels in women. The study was registered at ClinicalTrials.gov as NCT02761434. Funding Sources Danone Research. Supporting Tables, Images and/or Graphs


1992 ◽  
Vol 127 (6) ◽  
pp. 494-498 ◽  
Author(s):  
MA Arnaout ◽  
K Ajlouni

The neurohypophyseal function was assessed in a group of 15 patients with postpartum hypopituitarism by measuring plasma arginine-vasopressin concentrations during 5% hypertonic saline infusion. None of the patients had symptoms of diabetes insipidus and all patients were on adequate cortisone and thyroxine replacement therapy before testing. The mean basal plasma vasopressin value in the patients (0.6±0.1 pmol/1) was significantly lower than that in the normal subjects (2.9±0.3 pmol/l; p<0.01), whereas the mean serum sodium, plasma osmolality, plasma renin activity and serum aldosterone values were similar in the two groups. During the osmolar load (5% hypertonic saline), the patients revealed varying degrees of arginine-vasopressin responses to the increase in plasma osmolality. Three patients showed normal arginine-vasopressin responses, 10 had subnormal responses, and 2 had no response. During the dehydration test, the patients revealed significantly lower maximum urine osmolalities (p<0.0025) with significantly higher concurrent mean plasma osmolality (p<0.0025) than the controls. None of the patients showed overt polyuria at the time of the study. The results indicate the impaired osmoregulation of arginine-vasopressin secretion to an osmolar stimuli in patients with postpartum hypopituitarism, suggesting neurohypophyseal damage. In patients with Sheehan's syndrome, partial diabetes insipidus seems to be much more frequent than previously believed.


1996 ◽  
Vol 271 (3) ◽  
pp. R757-R765 ◽  
Author(s):  
N. S. Stachenfeld ◽  
G. W. Mack ◽  
A. Takamata ◽  
L. DiPietro ◽  
E. R. Nadel

To assess the fluid regulatory responses in aging adults, we measured thirst perception and osmoregulation during and after infusion of hypertonic NaCl) saline in older (72 +/- 2 yr, n = 6) and younger (26 +/- n = 6) subjects. Hypertonic saline was infused at 0.1 min-1.kg-1 for 120 min. On a separate day, the same subjects were infused identically with isotonic saline as a control. After infusion and a 30-min equilibration period, the drank water ad libitum for 180 min. Hypertonic infusion led to graded increases in plasma osmolality (Posm; 18 +/- 2 and 20 +/- 2 mosmol/kgH2O) and percent changes plasma volume (16.2 +/- 1.9 and 18.0 +/- 1.2%) that were in older and younger subjects. Osmotically stimulated increases in thirst (94.8 +/- 18.9 and 88.3 +/- 25.6 mm), assessed on a line rating scale, and plasma arginine vasopressin concentration (6.08 +/- 1.50 and 4.51 +/- 1.37 pg/ml, for older younger, respectively) were also unaffected by age. subsequent hypervolemia, both groups of subjects sufficient water to restore preinfusion levels of Posm. Renal handling of free water and sodium was also unaffected by age during recovery from hypertonic saline infusion, but was significantly lower in older subjects during recovery from saline infusion, resulting in net fluid retention and a significant fall in Posm (6 mosmol/kgH2O). In contrast to earlier reports of a blunted thirst response to dehydration hypertonicity, we found that osmotically stimulated thirst and renal osmoregulation were intact in older adults after hypertonic saline infusion.


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