Endogenous angiotensin ii and baroreflex control of sympathetic activity in sodium deprived rats: Role of the area postrema

L. Xu, J. P. Collister, J. W. Osborn, Virginia Brooks

Research output: Contribution to journalArticle

Abstract

The hypothesis that endogenous angiotensin II (AII) acts at the area postrema (AP) to increase lumbar sympathetic nerve activity (LSNA) and heart rate (HR) over the entire baroreflex range of arterial pressure (BP) was tested in conscious rats. Three groups of male rats, AP lesioned (APX, n=8), sham with food restriction (SFR, n=7), and sham with food ad libitum (SAL, n=8) were placed on sodium deficient diet for 2-3 weeks to increase endogenous AII levels. Rats were instrumented with a nerve electrode and catheterized for BP measurement and drug delivery. One to two days later, baroreflex curves were generated by changing BP with nitroprusside and phenylephrine, before and 40 min after injection of losartan (LOS; 10 mg/kg, iv), the AII type 1 receptor antagonist. Post-LOS hypotension was prevented by methoxamine infusion. LOS produced similar decreases in LSNA from 100±0 to 63±3, 56±7, and 64±5 %, in the APX, SFR and SAL groups, respectively (all p

Original languageEnglish (US)
JournalFASEB Journal
Volume11
Issue number3
StatePublished - 1997
Externally publishedYes

Fingerprint

Area Postrema
angiotensins
Baroreflex
angiotensin II
Angiotensins
Rats
nerve tissue
Sodium
sodium
Angiotensin II
rats
Methoxamine
Angiotensin II Type 1 Receptor Blockers
Food
phenylephrine
Losartan
hypotension
Nitroprusside
Phenylephrine
Nutrition

ASJC Scopus subject areas

  • Agricultural and Biological Sciences (miscellaneous)
  • Biochemistry, Genetics and Molecular Biology(all)
  • Biochemistry
  • Cell Biology

Cite this

Endogenous angiotensin ii and baroreflex control of sympathetic activity in sodium deprived rats : Role of the area postrema. / Xu, L.; Collister, J. P.; Osborn, J. W.; Brooks, Virginia.

In: FASEB Journal, Vol. 11, No. 3, 1997.

Research output: Contribution to journalArticle

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