Estrogen-induced refractoriness to the pressor effects of infused angiotensin II

Charles R. Rosenfeld, G. Marc Jackson

Research output: Contribution to journalArticle

56 Citations (Scopus)

Abstract

Estrogen may be important in the hemodynamic changes that develop during pregnancy; its role in the development of vascular refractoriness to the pressor effects of infused angiotensin II is unknown. We, therefore, examined the pressor responses to six doses of angiotensin II (0.115 to 5.73 μg/min) in unanesthetized, nonpregnant sheep both before and after treatment with either high-dose or low-dose 17β-estradiol (E2) and constructed dose-response curves. Although mean arterial pressure was unchanged after the infusion of E2, cardiac output rose 28% and systemic vascular resistance fell 19% (p < 0.001). Infused angiotensin II resulted in dose-dependent rises in mean arterial pressure before and after E2; however, the pressor response after E2 was decreased 30% to 50%. Plasma renin activity rose from 1.15 ± 0.09 ng/ml · hr to 2.57 ± 0.39 and 3.21 ± 0.61 ng/ml · hr with low-dose and high-dose E2, respectively (p < 0.05). Acutely estrogenized nonpregnant sheep develop significant alterations in both the cardiovascular and the renin-angiotensin systems in addition to decreased pressor responsiveness to infused angiotensin II. Although our findings suggest that estrogen may be important in the development of the vascular refractoriness to angiotensin II seen in pregnancy, additional studies are needed to clarify the role of each E2-induced change.

Original languageEnglish (US)
Pages (from-to)429-435
Number of pages7
JournalAmerican Journal of Obstetrics and Gynecology
Volume148
Issue number4
DOIs
StatePublished - Feb 15 1984

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Angiotensin II
Estrogens
Blood Vessels
Sheep
Arterial Pressure
Pregnancy
Renin-Angiotensin System
Renin
Cardiac Output
Vascular Resistance
Estradiol
Hemodynamics

ASJC Scopus subject areas

  • Medicine(all)
  • Obstetrics and Gynecology

Cite this

Estrogen-induced refractoriness to the pressor effects of infused angiotensin II. / Rosenfeld, Charles R.; Jackson, G. Marc.

In: American Journal of Obstetrics and Gynecology, Vol. 148, No. 4, 15.02.1984, p. 429-435.

Research output: Contribution to journalArticle

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