Renal function and plasma arginine vasotocin during water deprivation in an Australian parrot, the galah (Cacatua roseicapilla)

1991 ◽  
Vol 161 (6) ◽  
pp. 620-625 ◽  
Author(s):  
Juliet R. Roberts
Keyword(s):  
Renal Function ◽  
Water Deprivation ◽  
Arginine Vasotocin ◽  
Plasma Arginine

Effects of Water-Deprivation on Renal-Function and Plasma Arginine Vasotocin in the Feral Chicken, Gallus-Gallus (Phasianidae)

1991 ◽  
Vol 39 (4) ◽  
pp. 439 ◽  
Author(s):  
JR Roberts
Keyword(s):  
Renal Function ◽  
Water Availability ◽  
Filtration Rate ◽  
Water Deprivation ◽  
Arginine Vasotocin ◽  
Constant Infusion ◽  
Osmotic Minipumps ◽  
Diuretic Hormone ◽  
Infusion Method ◽  
Plasma Arginine

Feral chickens occur on a coral atoll off the coast of Queensland, Australia, where the availability of water is limited. Glomerular filtration rate (GFR) was measured in conscious unrestrained feral chickens by means of osmotic minipumps in fully hydrated birds and in birds subjected to a four-day period of water deprivation. Plasma ionic and osmotic concentrations were measured on each day of the experiment. During water deprivation, body weight decreased and plasma ionic and osmotic concentrations increased. Haematocrit was not significantly affected by dehydration. GFR fell on days 2, 3 and 4 of water deprivation to 62% of hydrated values. The plasma levels of the avian diuretic hormone, arginine vasotocin (AVT), increased by a factor of 2.8 over the period of water deprivation. The sensitivity of release of AVT in the feral chicken is higher than that reported for domestic strains of chickens. This may be related to the ability of the feral strain to survive in regions of limited water availability. GFR was measured also by the 'constant infusion' method, which was not significantly different from GFR measured by osmotic minipumps.

Regulation of plasma arginine vasotocin in conscious water-deprived domestic fowl

1986 ◽  
Vol 250 (4) ◽  
pp. R658-R664 ◽  
Author(s):  
J. N. Stallone ◽  
E. J. Braun
Keyword(s):  
Antidiuretic Hormone ◽  
Fluid Balance ◽  
Intravenous Infusion ◽  
Domestic Fowl ◽  
Water Deprivation ◽  
Extracellular Volume ◽  
Plasma Osmolality ◽  
Arginine Vasotocin ◽  
Plasma Arginine

Radioimmunoassay methods were employed to quantitatively characterize secretion of the avian antidiuretic hormone [arginine vasotocin (AVT)] by the hypothalamo-neurohypophyseal system (HNS) of the conscious domestic fowl in response to chronic dehydration. Water deprivation permitted characterization of AVT secretion in response to the combined stimuli of extracellular hyperosmolality and hypovolemia; the subsequent repletion of extracellular volume permitted separation of potential osmotic and volemic factors involved in the regulation of AVT secretion. In normally hydrated birds, plasma AVT (PAVT) and plasma osmolality (Posm) averaged 2.2 +/- 0.3 microU/ml (10.5 +/- 1.4 pg/ml) and 309.3 +/- 0.7 mosmol/kg H2O, respectively (means +/- SE). With water deprivation, PAVT and Posm of the birds increased in parallel in a curvilinear manner to maxima of 13.1 +/- 0.6 microU/ml (62.4 +/- 2.9 pg/ml) and 346.6 +/- 2.0 mosmol/kg H2O, respectively, at 96 h of dehydration. The isosmotic repletion of extracellular volume at 96 h by acute intravenous infusion failed to alter 96-h PAVT values. The results indicate that AVT secretion is closely linked to the state of hydration during negative fluid balance in the domestic fowl. Analysis of the data indicated that increases in PAVT that occur with dehydration are mediated primarily by extracellular hyperosmolality and that the HNS of the domestic fowl is relatively insensitive to the simultaneous hypovolemia incurred with fluid deprivation.

Osmotic and volemic regulation of plasma arginine vasotocin in conscious domestic fowl

1986 ◽  
Vol 250 (4) ◽  
pp. R644-R657
Author(s):  
J. N. Stallone ◽  
E. J. Braun
Keyword(s):  
Antidiuretic Hormone ◽  
Domestic Fowl ◽  
Hormone Secretion ◽  
Plasma Osmolality ◽  
Arginine Vasotocin ◽  
Antidiuretic Hormone Secretion ◽  
Primary Determinant ◽  
Plasma Arginine ◽  
Highly Correlated ◽  
Secretory System

Recently developed radioimmunoassay methods were utilized to quantitatively characterize secretion of the avian antidiuretic hormone [arginine vasotocin (AVT)] by the hypothalamo-neurohypophyseal system (HNS) of the conscious domestic fowl. The functional characteristics of the osmoreceptor-HNS were evaluated during independent experimental manipulations of extracellular osmolality or volume. Simultaneous measurements of plasma AVT (PAVT) and either plasma osmolality (Posm) or blood volume (BV) in these experiments permitted determination of osmoreceptor sensitivity to independent osmotic or volemic stimuli and set point of the AVT secretory system under conditions of normal hydration. In normally hydrated birds, PAVT and Posm averaged 2.7 +/- 0.2 microU/ml (12.9 +/- 1.0 pg/ml) and 308.1 +/- 0.6 mosmol/kg H2O, respectively (means +/- SE). Characterization of AVT secretion revealed that Posm is a primary determinant of AVT secretion by the HNS of the domestic fowl. Highly correlated and significant relationships between Posm and PAVT exist both above and below the observed basal Posm of normally hydrated birds, with an apparent osmotic threshold for AVT secretion at a Posm of 288.8 mosmol/kg H2O. Analysis of the data also suggested that the HNS is insensitive to changes in BV less than or equal to 10%, because neither isotonic expansion nor reduction of BV altered PAVT. Comparison of past and present avian data with that of the mammalian HNS indicates that 1) the osmotic regulation of antidiuretic hormone secretion is qualitatively and quantitatively similar in birds and mammals, and 2) the volemic regulation of antidiuretic hormone secretion is substantially more important in mammals than in birds.

Effect of acute manipulation of blood volume and osmolality on plasma [AVT] in seawater flounder

1995 ◽  
Vol 269 (5) ◽  
pp. R1107-R1112 ◽  
Author(s):  
J. M. Warne ◽  
R. J. Balment
Keyword(s):  
Linear Relationship ◽  
Blood Volume ◽  
Intraperitoneal Injection ◽  
Natural Variation ◽  
Plasma Osmolality ◽  
Arginine Vasotocin ◽  
Plasma Composition ◽  
Separate Study ◽  
Positive Linear Relationship ◽  
Plasma Arginine

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.

Effect of acute water deprivation on renal function in rats

1988 ◽  
Vol 9 (3) ◽  
pp. 259-265 ◽  
Author(s):  
P. Prasad ◽  
S. Niazi ◽  
D. Jung
Keyword(s):  
Renal Function ◽  
Water Deprivation
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