RELEASE AND RENAL ACTIONS OF THE AVIAN ANTIDIURETIC HORMONE, ARGININE VASOTOCIN.

Persistent Link:
http://hdl.handle.net/10150/187737
Title:
RELEASE AND RENAL ACTIONS OF THE AVIAN ANTIDIURETIC HORMONE, ARGININE VASOTOCIN.
Author:
STALLONE, JOHN NICHOLAS.
Issue Date:
1984
Publisher:
The University of Arizona.
Rights:
Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
Abstract:
Recently developed radioimmunoassay (RIA) techniques were employed in a quantitative investigation of the release and renal actions of the avian antidiuretic hormone, arginine vasotocin (AVT) in the conscious domestic fowl. The investigation was composed of a series of three studies with goals to: (1) define the functional characteristics of the avian hypothalamo-neurohypophysial system (HNS) in terms of the extracellular osmotic and volemic stimuli that elicit release of AVT; (2) characterize responses of the HNS to the natural challenge of negative fluid balance; and (3) quantify the relative contributions of AVT-induced glomerular and tubular antidiuresis to the conservation of water by the avian kideny. Characterization of AVT secretion revealed that plasma osmolality (P(OSM)) is a primary determinant of AVT secretion by the HNS of the domestic fowl. Highly correlated and significant relationships between P(OSM) and plasma AVT (P(AVT)) exist both above and below the observed basal P(OSM) of normally hydrated birds. Analysis of the present data also suggested that the HNS is insensitive to changes in blood volume of 10% or less, since neither isotonic expansion nor reduction of blood volume altered P(AVT). The results of the fluid deprivation experiments 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 P(AVT) that occur with dehydration are mediated primarily by extracellular hyperosmolality and that the HNS is relatively insensitive to the simultaneous hypovolemia incurred with fluid deprivation. Comparison to the dose-response relationships between P(AVT) and glomerular and tubular mechanisms of antidiuresis over the entire range of physiological P(AVT) levels in the domestic fowl revealed that tubular mechanisms are of primary importance and glomerular mechanisms of secondary importance in the conservation of water by the avian kidney. The greatest proportion of the total AVT-induced reduction in renal water excretion occurred at low physiological P(AVT) levels and appeared to be the exclusive result of tubular mechanisms of antidiuresis. At high P(AVT) levels, glomerular and tubular mechanisms overlapped and their effects on water conservation could not be separated; however, only minor additional amounts of water were conserved by the combined actions of glomerular and tubular mechanisms. Thus glomerular mechanisms appear to have only a minor, secondary effect on water conserving ability of the avian kidney.
Type:
text; Dissertation-Reproduction (electronic)
Keywords:
Vasopressin -- Analysis.; Vasopressin -- Physiological effect.; Poultry -- Physiology.; Diuresis.
Degree Name:
Ph.D.
Degree Level:
doctoral
Degree Program:
Physiology; Graduate College
Degree Grantor:
University of Arizona
Advisor:
Braun, Eldon J.

Full metadata record

DC FieldValue Language
dc.language.isoenen_US
dc.titleRELEASE AND RENAL ACTIONS OF THE AVIAN ANTIDIURETIC HORMONE, ARGININE VASOTOCIN.en_US
dc.creatorSTALLONE, JOHN NICHOLAS.en_US
dc.contributor.authorSTALLONE, JOHN NICHOLAS.en_US
dc.date.issued1984en_US
dc.publisherThe University of Arizona.en_US
dc.rightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.en_US
dc.description.abstractRecently developed radioimmunoassay (RIA) techniques were employed in a quantitative investigation of the release and renal actions of the avian antidiuretic hormone, arginine vasotocin (AVT) in the conscious domestic fowl. The investigation was composed of a series of three studies with goals to: (1) define the functional characteristics of the avian hypothalamo-neurohypophysial system (HNS) in terms of the extracellular osmotic and volemic stimuli that elicit release of AVT; (2) characterize responses of the HNS to the natural challenge of negative fluid balance; and (3) quantify the relative contributions of AVT-induced glomerular and tubular antidiuresis to the conservation of water by the avian kideny. Characterization of AVT secretion revealed that plasma osmolality (P(OSM)) is a primary determinant of AVT secretion by the HNS of the domestic fowl. Highly correlated and significant relationships between P(OSM) and plasma AVT (P(AVT)) exist both above and below the observed basal P(OSM) of normally hydrated birds. Analysis of the present data also suggested that the HNS is insensitive to changes in blood volume of 10% or less, since neither isotonic expansion nor reduction of blood volume altered P(AVT). The results of the fluid deprivation experiments 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 P(AVT) that occur with dehydration are mediated primarily by extracellular hyperosmolality and that the HNS is relatively insensitive to the simultaneous hypovolemia incurred with fluid deprivation. Comparison to the dose-response relationships between P(AVT) and glomerular and tubular mechanisms of antidiuresis over the entire range of physiological P(AVT) levels in the domestic fowl revealed that tubular mechanisms are of primary importance and glomerular mechanisms of secondary importance in the conservation of water by the avian kidney. The greatest proportion of the total AVT-induced reduction in renal water excretion occurred at low physiological P(AVT) levels and appeared to be the exclusive result of tubular mechanisms of antidiuresis. At high P(AVT) levels, glomerular and tubular mechanisms overlapped and their effects on water conservation could not be separated; however, only minor additional amounts of water were conserved by the combined actions of glomerular and tubular mechanisms. Thus glomerular mechanisms appear to have only a minor, secondary effect on water conserving ability of the avian kidney.en_US
dc.typetexten_US
dc.typeDissertation-Reproduction (electronic)en_US
dc.subjectVasopressin -- Analysis.en_US
dc.subjectVasopressin -- Physiological effect.en_US
dc.subjectPoultry -- Physiology.en_US
dc.subjectDiuresis.en_US
thesis.degree.namePh.D.en_US
thesis.degree.leveldoctoralen_US
thesis.degree.disciplinePhysiologyen_US
thesis.degree.disciplineGraduate Collegeen_US
thesis.degree.grantorUniversity of Arizonaen_US
dc.contributor.advisorBraun, Eldon J.en_US
dc.contributor.committeememberDantzler, William H.en_US
dc.contributor.committeememberSawyer, Wilbur H.en_US
dc.contributor.committeememberStouffer, Richard L.en_US
dc.identifier.proquest8421984en_US
dc.identifier.oclc691323138en_US
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