Ontogeny of angiotensin II vascular smooth muscle receptors in ovine fetal aorta and placental and uterine arteries

C. R. Rosenfeld, B. E. Cox, R. R. Magness, P. W. Shaul

Research output: Contribution to journalArticle

18 Scopus citations

Abstract

OBJECTIVE: Our purpose was to determine if differences in angiotensin II vascular smooth muscle receptor binding account for the attenuated fetal placental and systemic responses to infused angiotensin II relative to maternal responses and for the differences between umbilical and fetal systemic responses. STUDY DESIGN: Using plasma membranes prepared from the medial layer of fetal aorta, fetal placental artery, and maternal uterine artery obtained between 107 and 134 days of ovine gestation (n = 17), we measured and compared angiotensin II receptor binding density (in femtomoles per milligram of protein) and affinity (in nanomoles per liter) in radioligand binding studies with iodine 125-angiotensin II. Maternal and fetal plasma angiotensin II were also compared. RESULTS: A single class of high-affinity receptor was identified in all arteries. Although the binding density was similar at < 100 and > 130 days for fetal aorta (388 ± 87 [SE] vs 262 ± 56), placental artery (319 ± 95 vs 235 ± 54), and uterine artery (46 ± 6 vs 50 ± 13), values for fetal arteries exceeded those for uterine arteries (p ≤ 0.018) in spite of higher fetal plasma angiotensin II (74 ± 18 vs 30 ± 8 pg/ml, p < 0.01). Affinity did not differ between arteries and, except for fetal aorta (1.4 ± 0.2 vs 2.1 ± 0.4, r = 0.49, p = 0.045), was unchanged during late gestation. CONCLUSION: Differences between fetal and maternal responses and fetal placental and systemic responses to infused angiotensin II in sheep do not reflect alterations in total angiotensin II vascular smooth muscle receptor binding density or affinity.

Original languageEnglish (US)
Pages (from-to)1562-1569
Number of pages8
JournalAmerican journal of obstetrics and gynecology
Volume168
Issue number5
DOIs
StatePublished - Jan 1 1993

Keywords

  • Receptors
  • angiotensin II
  • fetus
  • pregnancy

ASJC Scopus subject areas

  • Obstetrics and Gynecology

Fingerprint Dive into the research topics of 'Ontogeny of angiotensin II vascular smooth muscle receptors in ovine fetal aorta and placental and uterine arteries'. Together they form a unique fingerprint.

  • Cite this