ANGIOTENSIN II, VASOPRESSIN AND THE BARORECEPTOR REFLEX

Project: Research project

Description

Intravenous infusion of angiotensin II (AII) alters the baroreceptor reflex
such that heart rate and plasma concentrations of vasopressin and ACTH are
elevated above normal at each level of arterial blood pressure. To
determine whether AII increases the levels of these hormones and heart rate
by decreasing the tonic inhibitory effect of input from arterial and low
pressure stretch receptors, the effect of abroreceptor denervation on the
vasopressin, ACTH and cardiac response to AII will be studied. The role of
the area postrema in the responses will be investigated by determining the
effect of intravertebral infusion of AII or lesions of the area postrema on
function of the baroreceptor reflex. Baroreflex function will be assessed
by examining the relationship between blood pressure and each of three
parameters: heart rate and systemic concentrations of vasopressin and
ACTH. Blood pressure will be varied either by infusion of nitroprusside
and phenylephrine, or by hemorrhage. Vasopressin infusion also appears to affect baroreflex function by
enhancing the strength of the reflex. To determine whether the area
postrema mediates this action, the effect of vasopressin infusion on
baroreflex control of ACTH secretion in dogs with lesions of this structure
will be studied. Whether vasopressin infusion enhances reflex release of
ACTH secretion will also be investigated. Finally, the role of endogenous
AII and vasopressin in regulation of the baroreceptor reflex during
hemorrhage and water deprivation will be examined by infusion of blockers
of the renin-angiotensin system or a vasopressin antagonist.
StatusFinished
Effective start/end date7/1/863/31/04

Funding

  • National Institutes of Health
  • National Institutes of Health
  • National Institutes of Health: $201,070.00
  • National Institutes of Health
  • National Institutes of Health
  • National Institutes of Health: $179,452.00
  • National Institutes of Health
  • National Institutes of Health: $139,735.00
  • National Institutes of Health: $191,106.00
  • National Institutes of Health: $197,556.00
  • National Institutes of Health: $151,326.00
  • National Institutes of Health

Fingerprint

Angiotensin II
Baroreflex
Neuropeptides
Vasopressins
Norepinephrine Plasma Membrane Transport Proteins
Tyrosine 3-Monooxygenase
Renin-Angiotensin System
Arterial Pressure
Salts
Adrenocorticotropic Hormone
Sympathetic Nervous System
Area Postrema
Catecholamines
Corticosterone
Pressoreceptors
Sodium Chloride
Reflex
Hypertension
Blood Pressure
Heart Rate

ASJC

  • Medicine(all)