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Ovariectomy induces an enhanced sensitivity to angiotensin II in female growth restricted rats
Author(s) -
Ojeda Norma B,
Royals Thomas P,
Alexander Barbara T
Publication year - 2010
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.24.1_supplement.1041.8
Subject(s) - medicine , endocrinology , angiotensin ii , intrauterine growth restriction , enalapril , renal function , blood pressure , mean arterial pressure , angiotensin converting enzyme , biology , heart rate , pregnancy , fetus , genetics
Placental insufficiency in the rat results in intrauterine growth restriction (IUGR) and sex differences in adult hypertension. Male IUGR are hypertensive; ovariectomy (OVX) induces hypertension in female IUGR suggesting estradiol (E) may provide a protective status. Enhanced sensitivity to acute angiotensin II (ANG II) is observed in male IUGR, but not in intact normotensive female IUGR. Thus, the purpose of this study was to determine if OVX enhances sensitivity to ANG II in female IUGR. Female rats were subjected to OVX or sham OVX at 10 weeks of age. Cardio‐renal physiological parameters were determined before and after acute infusion of ANG II (100 ng/kg/min for 30 minutes) at 16 weeks of age in rats pretreated with enalapril (250 mg/L for 1 week). Mean arterial pressure (MAP) and renal vascular resistance (RVR) were increased to a greater extent in OVX IUGR; a greater decrease in glomerular filtration rate (GFR) was observed in OVX IUGR. Thus, these data suggest that estradiol modulates renal responsiveness to ANG II in female IUGR and may contribute to sex differences in IUGR hypertension.Response after acute ANG II Increase in MAP (mmHg) Increase in RVR (mmHg/ml/min) Decrease in GFR (ml/min)Control female intact 21±0.5 8±3 2.3±0.3IUGR female intact 20±9 16±7 2.3±0.3Control female OVX 18±2 12±6 3.5±0.9IUGR female OVX 49±4 * † 17±1.5 * † 5.1±0.1 * †* P < 0.05 vs. control OVX † P < 0.05 vs. intact IUGR