Abstract P172: Impairment Of Estrogen Protective Effect Contributes To Maternal Gestational Hypertension-induced Sensitization Of Hypertensive Response To Post-weaning High Fat Diet In Female Adult Offspring

Abstract

Obesity/high fat diet (HFD) is a risk factor for cardiovascular diseases including hypertension. Recent evidence indicates that maternal gestational hypertension (MGHT) induces hypertensive response sensitization (HTRS) elicited by post-weaning HFD in both male and female offspring. However, the increase in blood pressure (BP) in female offspring is less than that in male offspring. In this study, we investigated if estrogen plays a protective role in MGHT-induced HTRS to post-weaning HFD in female offspring, and if estrogen effects are associated with regulation of brain reactivity to pressor agents and altered autonomic function. In post-weaning HFD fed intact female offspring, MGHT induced HFD-elicited HTRS (MAP, offspring of NT dams, 107.9±0.9 to 115.2±0.7 mmHg; offspring of MGHT dams, 107.3±0.8 to 120.7±1.4 mmHg, p<0.05) and enhanced pressor responses to centrally administered angiotensin (ANG) II (Δ13.7±1.1 mmHg, p<0.05 vs NFD offspring) and tumor necrosis factor α (TNF-α) (Δ13.1±0.7 mmHg, p<0.05 vs NFD offspring). Ovariectomy (OVX) significantly enhanced the HFD-induced increase in BP (115.2±0.7 to 127.1±2.2 mmHg, p<0.05) and the pressor response to central ANG II (Δ11.2±0.9 to Δ18.7±2.3 mmHg, p<0.05) or TNF-α (Δ10.0±1.0 to Δ16.5±1.6 mmHg, p<0.05) in HFD offspring of normotensive (NT) dams. However, MGHT-induced HTRS (MAP, 122.5±1.9 mmHg) and pressor responses to ANG II (Δ16.3±1.0 mmHg) or TNF-α (Δ14.9±1.0 mmHg) in HFD-fed intact offspring of MGHT dams were not potentiated further after OVX when compared to HFD-fed OVX offspring of NT dams. The resting BP and elicited pressor responses remained higher than that of NFD fed offspring of both NT and MGHT dams. Moreover, OVX induced an increase in central nervous system sympathetic drive, and HFD feeding potentiated this effect. The results indicate that estrogen normally plays a protective role in antagonizing HFD prohypertensive effects in offspring of NT dams. MGHT compromises this normal protective action of estrogen to induce HTRS elicited by HFD, which is through augmenting brain reactivity and centrally driven sympathetic activity.