Abstract P442: Estradiol Treatment Attenuates the Ovariectomy-induced Increase in Blood Pressure in the Middle Aged Dahl Salt Sensitive Rat as Long as Treatment is Initiated Immediately After Ovariectomy

• Published in: Hypertension (Dallas, Tex. 1979) Tex. 1979), 2017-09, Vol.70 (suppl_1)
• Main Authors: Ji, Hong, West, Crystal A, Wu, Xie, Pai, Amrita, Souza, Aline, Kadam, Parnika, West, David A, Zhu, Michelle J, Sandberg, Kathryn
• Format: Article
• Language: English
• ISSN: 0194-911X; 1524-4563
• DOI: 10.1161/hyp.70.suppl_1.p442

Abstract only Introduction: Several studies have shown that ovariectomy increases blood pressure and that 17beta-estradiol ( E 2 ) treatment can attenuate this effect; however, the majority of these studies were conducted in young animals in which E 2 replacement was initiated soon after ovariectomy. Since most women who experience ovarian hormone loss are middle aged rather than young, this study investigated the effect of E 2 replacement in middle aged Dahl salt-sensitive ( DS ) rats. In addition, the time at which E 2 replacement was initiated was examined. Methods: DS rats were ovariectomized ( OVX ) at 4.5 months ( mo ) ( DS-OVX Y ) and 7mo ( DS-OVX O ). At 7mo, half of OVX DS rats in each group were treated with E 2 for 4 weeks ( DS-OVX Y +E 2 , DS-OVX O +E 2 ). Mean arterial pressure ( MAP ) was measured by telemetry in all treatment groups from 7-8mo. Body weights were measured throughout the experiment and plasma angiotensin II ( AngII ) was determined at time of sacrifice (8mo) by RAS fingerprint. Results: E 2 treatment at 7mo had no effect on MAP in the DS rats OVX at early age [MAP (mmHg) at 8mo: DS-OVX Y , 180±5.3 vs. DS-OVX Y +E 2 , 179±4.6, ns; n=4/group]. In contrast, one month of E 2 treatment prevented the ovariectomy-induced increase in MAP when OVX at late age [MAP (mmHg): DS-OVX O , 191±1.6 vs. DS-OVX O +E 2 , 177±2.9, p