Glucocorticoid-induced fetal programming alters the functional complement of angiotensin receptor subtypes within the kidney

Hypertension. 2011 Mar;57(3):620-6. doi: 10.1161/HYPERTENSIONAHA.110.164970. Epub 2011 Jan 10.

Abstract

We examined the impact of fetal programming on the functional responses of renal angiotensin receptors. Fetal sheep were exposed in utero to betamethasone (BMX; 0.17 mg/kg) or control (CON) at 80 to 81 days gestation with full-term delivery. Renal nuclear and plasma membrane fractions were isolated from sheep age 1.0 to 1.5 years for receptor binding and fluorescence detection of reactive oxygen species (ROS) or nitric oxide (NO). Mean arterial blood pressure and blood pressure variability were significantly higher in the BMX-exposed adult offspring versus CON sheep. The proportion of nuclear AT(1) receptors sensitive to losartan was 2-fold higher (67 ± 6% vs 27 ± 9%; P<0.01) in BMX compared with CON. In contrast, the proportion of AT(2) sites was only one third that of controls (BMX, 25 ± 11% vs CON, 78 ± 4%; P<0.01), with a similar reduction in sites sensitive to the Ang-(1-7) antagonist D-Ala7-Ang-(1-7) with BMX exposure. Functional studies revealed that Ang II stimulated ROS to a greater extent in BMX than in CON sheep (16 ± 3% vs 6 ± 4%; P<0.05); however, NO production to Ang II was attenuated in BMX (26 ± 7% vs 82 ± 14%; P<0.05). BMX exposure was also associated with a reduction in the Ang-(1-7) NO response (75 ± 8% vs 131 ± 26%; P<0.05). We conclude that altered expression of angiotensin receptor subtypes may be one mechanism whereby functional changes in NO- and ROS-dependent signaling pathways may favor the sustained increase in blood pressure evident in fetal programming.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Analysis of Variance
  • Angiotensin II / metabolism
  • Angiotensin II / pharmacology
  • Angiotensin II Type 1 Receptor Blockers / pharmacology
  • Animals
  • Betamethasone / metabolism
  • Betamethasone / pharmacology*
  • Blood Pressure / drug effects
  • Blood Pressure / physiology
  • Female
  • Fetal Development / drug effects*
  • Glucocorticoids / metabolism
  • Glucocorticoids / pharmacology*
  • Kidney / drug effects
  • Kidney / metabolism*
  • Losartan / pharmacology
  • Nitric Oxide / metabolism
  • Pregnancy
  • Prenatal Exposure Delayed Effects / metabolism*
  • Reactive Oxygen Species / metabolism
  • Receptors, Angiotensin / metabolism*
  • Sheep

Substances

  • Angiotensin II Type 1 Receptor Blockers
  • Glucocorticoids
  • Reactive Oxygen Species
  • Receptors, Angiotensin
  • Angiotensin II
  • Nitric Oxide
  • Betamethasone
  • Losartan