title: Exercise training associated with estrogen therapy induced cardiovascular benefits after ovarian hormones deprivation.
abstract: Menopause is recognized as a period of increased risk for coronary heart disease. Although the benefits of exercise training in lowering cardiovascular risk factors are well established, the risks and benefits of hormone therapy have been questioned. The purpose of the present study was to investigate the effects of estrogen therapy (HT) associated or not with exercise training (ET) in autonomic cardiovascular control in ovariectomized (OVX) rats. Female rats were divided into: control, OVX, OVX+HT, OVX+ET and OVX+HT+ET. HT was performed using a 0.25mg 8-weeks sustained release pellet. Trained groups were submitted to an 8-week exercise training protocol on treadmill. Baroreflex sensitivity (BRS) was evaluated by heart rate responses to arterial pressure (AP) changes, and vagal and sympathetic tonus by pharmacological blockade. Ovariectomy induced an AP increase (123+/-2mmHg vs. 108+/-2mmHg), BRS impairment ( approximately 69%), sympathetic activation ( approximately 100%) and vagal tonus reduction ( approximately 77%) compared to controls. HT or ET normalized the changes in parasympathetic tonus. However, only the association HT+ET was able to promote normalization of AP, BRS and sympathetic tonus, as compared to controls. These results indicate that ET induces cardiovascular and autonomic benefits in OVX rats under HT, suggesting a positive role of this association in the management of cardiovascular risk factor in postmenopausal women.
authors.affiliation: Hypertension Unit, Heart Institute (InCor), University of Sao Paulo Medical School, Sao Paulo, Brazil.
authors.forename: Karin
authors.initials: K
authors.lastname: Flues
authors.forename: Janaina
authors.initials: J
authors.lastname: Paulini
authors.forename: Sebastião
authors.initials: S
authors.lastname: Brito
authors.forename: Iris Callado
authors.initials: IC
authors.lastname: Sanches
authors.forename: Fernanda
authors.initials: F
authors.lastname: Consolim-Colombo
authors.forename: Maria-Cláudia
authors.initials: MC
authors.lastname: Irigoyen
authors.forename: Kátia
authors.initials: K
authors.lastname: De Angelis
mesh_terms: D000818:Animals; D001341:Autonomic Nervous System / Q000187:drug effects*; D017704:Baroreflex / Q000187:drug effects; D001794:Blood Pressure / Q000187:drug effects; D002318:Cardiovascular Diseases / Q000517:prevention & control*; D015914:Estrogen Replacement Therapy; D004967:Estrogens / Q000172:deficiency; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D008593:Menopause / Q000502:physiology*; D010052:Ovariectomy; D010805:Physical Conditioning, Animal / Q000502:physiology*; D051381:Rats; D017208:Rats, Wistar; D012307:Risk Factors; D014630:Vagus Nerve / Q000187:drug effects
chemical_list: D004967:Estrogens