Log linear relationship between plasma arginine vasopressin and plasma osmolality.

1977 ◽  
Vol 233 (1) ◽  
pp. E37
Author(s):  
R E Weitzman ◽  
D A Fisher

The integrated plasma arginine vasopressin concentration (IpAVP) was determined by pooling the results of single samples collected every 3 min for 0.5 h in dehydrated, randomly hydrated, and water-loaded sheep. A linear relationship was observed between the log of the integrated AVP concentration and plasma osmolality. This relationship was tested by the bolus injection of 20 g/100 ml NaCl to both water-loaded and randomly hydrated sheep. The rise in the log of IpAVP divided by the rise in plasma osmolality was similar in both groups (P greater than 0.5) and was superimposable upon the regression line derived from steady-state observations. The data would suggest that AVP is released as an exponential function of plasma osmolality rather than as a threshold phenomenon.

1990 ◽  
Vol 122 (4) ◽  
pp. 455-461 ◽  
Author(s):  
San-e Ishikawa ◽  
Toshikazu Saito ◽  
Koji Okada ◽  
Shoichiro Nagasaka ◽  
Takeshi Kuzuya

Abstract. We studied the changes in plasma arginine vasopressin in 5 patients with diabetic ketoacidosis and one patient with non-ketotic hyperosmolar coma who had marked hyperglycemia (36.6 ± 4.6 mmol/l, mean ± sem) and dehydration. Plasma osmolality (Posm) was 342.2 ± 11.4 mOsm/kg H2O, and hematocrit, serum protein, and blood urea nitrogen were also elevated at hospitalization. Circulating blood volume was decreased by approximately 21% as compared with that on day 7. Plasma AVP level was increased to 8.5 ± 1.6 pmol/l at hospitalization. When hyperglycemia was improved by iv infusion of a small dose of insulin plus fluid administration, plasma AVP level promptly decreased to 2.4 ± 0.4 pmol/l within six hours. When plasma AVP level had normalized, Posm was still as high as 305 mOsm/kg H2O, but the loss of circulating blood volume was only 4.2% of the control state. Plasma AVP level was positively correlated with change in hematocrit (plasma AVP = 3.58 + 0.45 · hematocrit, r = 0.468, p < 0.01), serum protein (r = 0.487, p < 0.01), Posm (r = 0.388, p < 0.01), and blood glucose (r = 0.582, p < 0.01). Plasma AVP level was negatively correlated with the change in circulating blood volume (plasma AVP = 3.6 – 0.14 · change in circulating blood volume, r = −0.469, p <0.01). These results indicate that both non-osmotic and osmotic stimuli are involved in the mechanism for AVP release in patients with diabetic coma, and that the non-osmotic control of AVP may contribute to circulating homeostasis, protecting against severe blood volume depletion in diabetic patients suffering from hyperglycemia and dehydration.


1981 ◽  
Vol 240 (2) ◽  
pp. E108-E111
Author(s):  
T. A. Reaves ◽  
H. M. Liu ◽  
M. M. Qasim ◽  
J. N. Hayward

This study examines the effects of blood osmolality on the release of arginine vasopressin (AVP) in the cat. Prior to the beginning of the experiments, the chamber-isolated, unanesthetized cat, allowed water ad libitum had a constant plasma osmolality averaging 320 +/- 2 (SE) mosmol/kg and a constant plasma AVP averaging 3.4 +/- 0.7 microU/ml. Water loading decreased plasma osmolality to 312 +/- 2 mosmol/kg and lowered plasma AVP to 1.3 +/- 0.2 microU/ml. As dehydration occurred during fluid restriction, the plasma osmolality increased and plasma AVP rose to 8 times the base line after 2 days. The rise in plasma AVP correlated linearly with the rise in plasma osmolality (r = 0.81; P less than 0.01). The cat's osmotic-vasopressin relationships are unique among mammals, revealing an elevated osmotic "set point" (threshold) and with regression analysis an increased "gain" or "'sensitivity" (increased slope of the regression line). We speculate that these unusual osmotic-AVP relationships may be related to some specialized features of the cat, such as hypothalamic anatomy or cerebral arterial blood supply.


1992 ◽  
Vol 126 (3) ◽  
pp. 217-223 ◽  
Author(s):  
Tokihisa Kimura ◽  
Kozo Ota ◽  
Masaru Shoji ◽  
Minoru Inoue ◽  
Kazutoshi Sato ◽  
...  

To assess whether arginine vasopressin and atrial natriuretic hormone participate in impaired urinary dilution and excretion in glucocorticoid deficiency secondary to hypopituitarism. an acute oral water load of 20 ml·kg−1 BW was undertaken in the absence and presence of an oral hydrocortisone (60 mg) treatment in patients with ACTH deficiency (N= 7) and panhypopituitarism (N = 2). Plasma arginine vasopressin and atrial natriuretic hormone and renal water handling were simultaneously determined and compared with those in similarly water-loaded normal subjects. Plasma arginine vasopressin did not fall in response to decreased blood osmolality after an acute water load in the absence of hydrocortisone; plasma atrial natriuretic hormone did not change despite blood volume expansion; and impairment in urinary dilution and excretion remained. On the other hand, in the presence of hydrocortisone, plasma arginine vasopressin fell in response to a decrease in plasma osmolality and plasma atrial natriuretic hormone increased, thereby restoring urinary dilution and excretion. These results demonstrate that the impaired arginine vasopressin response to acute water loading play an essential role in deranged renal water and electrolyte handling in the state of glucocorticoid deficiency; the impaired release of atrial natriuretic hormone also may affect these disorders.


1988 ◽  
Vol 75 (1) ◽  
pp. 35-39 ◽  
Author(s):  
M. J. Allen ◽  
V. T. Y. Ang ◽  
E. D. Bennett ◽  
J. S. Jenkins

1. Eight normal volunteers were infused with 5% saline (5 g of NaCl/100 ml) at a rate of 0.06 ml min−1 kg−1 for 120 min to increase plasma osmolality and plasma arginine vasopressin. Human atrial natriuretic peptide (α-hANP; 100 μg) or placebo was given in random order in a double-bind cross-over design for the last 20 min of the saline infusion. 2. Compared with the placebo infusion, atrial natriuretic peptide (ANP) produced a 43% greater sodium excretion and a 34% greater urinary volume in the subsequent hour. 3. Mean plasma immunoreactive ANP did not increase in response to changes in osmolality and rose to a peak of 118 pg/ml during the α-hANP infusion. α-hANP produced significant suppression of mean plasma arginine vasopressin over the 60 min after the infusions. 4. We conclude that ANP is not released in response to increased osmolality in vivo, and that it inhibits osmolality-induced arginine vasopressin release in man.


1993 ◽  
Vol 137 (3) ◽  
pp. 505-510 ◽  
Author(s):  
R. S. Weisinger ◽  
P. Burns ◽  
L. W. Eddie ◽  
E. M. Wintour

ABSTRACT During pregnancy, in women and the rat, there is a resetting of the plasma osmolality–arginine vasopressin relationship (Posmol/PAVP) such that a decrease in Posmol is maintained without suppression of PAVP. This occurs at a time when relaxin is detectable in plasma. The hypothesis tested here was that relaxin could alter the Posmol/PAVP in the non-pregnant rat. One group of ovariectomized rats (n = 15) was treated for 7 days with intravenous synthetic human relaxin (10 μg/h) in 10 pi 0·9% (w/v) NaCl. Controls were two groups of rats either with no treatment (n = 15) or treated with vehicle alone (n = 15). One-third of each group received hypertonic saline (0·4 mol NaCl/l, 2 ml/100 g body weight i.p.) on day 7, and one-third were deprived of water for the final 24 h. All rats were killed by decapitation and blood was collected rapidly (<40 s) for hormone and osmolality assays. The Posmol in all relaxin-treated rats was significantly (P < 0·001) lower than that in both control groups, but the PAVP was unchanged. The log PAVP/Posmol regression line was significantly shifted in elevation (P <0·001) but not in slope. Thus treatment of ovariectomized rats with relaxin caused changes in fluid balance which mimic those occurring in normal pregnancy. Journal of Endocrinology (1993) 137, 505–510


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.


1987 ◽  
Vol 114 (2) ◽  
pp. 243-248 ◽  
Author(s):  
P. Norsk ◽  
F. Bonde-Petersen ◽  
J. Warberg

Abstract. In order to examine the influence of carotid baroreceptor stimulation on arginine vasopressin secretion, 8 normal healthy males were subjected to static neck suction of −3.3 kPa for 20 min in the upright sitting position after overnight food and fluid restriction. The plasma concentration of arginine vasopressin did not change significantly during neck suction. However, in 3 subjects the termination of neck suction induced large increases in plasma arginine vasopressin from 1.8 to 63.7 ng/l, from 0.7 to 34.3 ng/l and from 2.1 to 19.0 ng/l, respectively. Two subjects experienced symptoms such as nausea and paleness during neck suction. Systolic arterial pressure increased slightly but significantly during neck suction from 15.3 ± 0.3 to 15.7 ± 0.4 kPa (N = 7, P < 0.05), whereas mean arterial pressure, diastolic arterial pressure, central venous pressure, heart rate, plasma osmolality, plasma sodium and potassium were unchanged. Haemoglobin concentration in blood and haematocrit increased significantly during and after neck suction, whereas plasma volume decreased. We conclude that neck suction with a negative pressure of 3.3 kPa in upright sitting man does not significantly affect plasma arginine vasopressin. However, termination of the stimulation induces large increases in some subjects. This may be explained by a direct effect on the vagus nerve or by a selective deloading of carotid baroreceptors.


1995 ◽  
Vol 269 (5) ◽  
pp. R1107-R1112 ◽  
Author(s):  
J. M. Warne ◽  
R. J. Balment

Chronically cannulated seawater (SW)-adapted flounder (Platichthys flesus) were used unanesthetized and unrestrained in an experimental series that acutely manipulated blood volume and plasma osmolality to determine their influence on plasma arginine vasotocin (AVT) concentrations. Immunoreactive AVT was measured using a radioimmunoassay validated for flounder and other teleosts. After hemorrhage-induced hypovolemia or hypervolemia produced by saline infusion, no major changes in plasma AVT concentrations were detected. Raising plasma osmolality by intraperitoneal injection of 1 M NaCl compared with control 150 mM NaCl-injected fish (329.4 +/- 3.4 vs. 320.4 +/- 3.0 mosmol/kgH2O, P < 0.05) produced an increase in plasma AVT concentration (6.7 +/- 1.2 vs. 4.2 +/- 0.2 fmol/ml, P < 0.05). In a separate study, plasma composition in a large number of uncannulated SW-adapted flounder was determined. This demonstrated a positive linear relationship between the natural variation in plasma AVT concentrations and plasma osmolality and Na+ and Cl- concentrations observed between fish. These data indicate that AVT secretion in SW-adapted flounder is closely related and perhaps directly sensitive to changes in plasma tonicity.


1975 ◽  
Vol 80 (3) ◽  
pp. 453-464 ◽  
Author(s):  
U. Merkelbach ◽  
P. Czernichow ◽  
R. C. Gaillard ◽  
M. B. Vallotton

ABSTRACT A radioimmunoassay for [8-arginine]-vasopressin (AVP), previously described (Czernichow et al. 1975) has been used for the determination of antidiuretic hormone in a 4 ml urine sample. AVP is extracted from acidified urine with a cation exchanger (Amberlite CG 50) with an overall recovery of 72 %. The blank value measured in extracted samples of urine was 0.29 pg/ml ± 0.21 (sem) and calculated by extrapolation of the regression line of the recovery experiment was 0.49 pg/ml. The coefficient of variation within-assay was 13 % and between-assay 18%. Addition of the amounts of AVP found in each specimen of urine voided gave results nearly identical to those of the amounts found in 24 h pool of urine, indicating that the assay was not affected by changes in concentration of the other urinary components during the day. The daily urinary excretion of AVP measured in 34 subjects was found to be 34 ng in 17 women and 70 ng in 17 men, a significant difference. Urinary concentration and excretion rate of AVP rose during thirst test and during Carter-Robbins test performed in 13 healthy subjects. In the latter test it was observed that the women displayed a strikingly more pronounced AVP elevation after the osmolar stimulus than the men. In both sexes a significant correlation was found between AVP excretion rate and plasma osmolality as well as free water clearance. Three cases of complete or incomplete diabetes insipidus and potomania could be clearly differentiated according to the total output of AVP during the thirst test. Extremely high values of AVP were found in the urine of 5 subjects with Schwartz-Bartter syndrome associated with bronchogenic tumours.


1979 ◽  
Vol 56 (5) ◽  
pp. 455-461 ◽  
Author(s):  
N. Siafakas ◽  
A. J. R. Morris ◽  
F. J. Prime

1. The initial rate of change of pressure at the mouth (dP/dt) during a brief occlusion of the airways at the beginning of inspiration has been estimated in nine healthy subjects at rest, during exercise and during the first 2 min of recovery. Exercise was carried out with progressively increasing loads to the maximum tolerated (progressive exercise) and also for a period of 6 min at a constant load of 60% of the maximum (steady-state exercise). 2. A highly significant linear relationship was found between work loads and dP/dt during progressive exercise in all our subjects. 3. A highly significant linear relationship was found between ventilation and dP/dt in both forms of exercise, but the slope of the regression line was steeper during progressive than during steady-state exercise in six out of nine subjects. 4. The pattern of breathing (VT, f, VT/Tinsp., Tinsp./Ttot.) did not account for the difference in the relationship between dP/dt and ventilation during the two forms of exercise. 5. These results are in agreement with the hypothesis that dP/dt is an index of central inspiratory drive.


Sign in / Sign up

Export Citation Format

Share Document