Renal function and plasma arginine vasotocin during an acute salt load in feral chickens

1992 ◽  
Vol 162 (1) ◽  
Author(s):  
JulietR. Roberts
Keyword(s):  
Renal Function ◽  
Arginine Vasotocin ◽  
Salt Load ◽  
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.

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.

Changes in Steady State Plasma Arginine Vasotocin Levels Affect Ovine Fetal Renal and Cardiovascular Function*

Endocrinology ◽  
1986 ◽  
Vol 118 (2) ◽  
pp. 759-765 ◽  
Author(s):  
M. GORE ERVIN ◽  
MICHAEL G. ROSS ◽  
ROSEMARY D. LEAKE ◽  
DELBERT A. FISHER
Keyword(s):  
Steady State ◽  
Cardiovascular Function ◽  
Arginine Vasotocin ◽  
Plasma Arginine ◽  
Ovine Fetal ◽  
State Plasma
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