title: Dynamic resistance training decreases sympathetic tone in hypertensive ovariectomized rats.
abstract: The aim of this study was to investigate the effects of resistance exercise training on hemodynamics and cardiac autonomic control in ovariectomized spontaneously hypertensive rats. Female rats were divided into 4 groups: sedentary control (SC), sedentary hypertensive (SH), sedentary hypertensive ovariectomized (SHO), and resistance-trained hypertensive ovariectomized (RTHO). Resistance exercise training was performed on a vertical ladder (5 days/week, 8 weeks) at 40-60% maximal load. Direct arterial pressure was recorded. Vagal and sympathetic tones were measured by heart rate (HR) responses to methylatropine (3 mg/kg, iv) and propranolol (4 mg/kg, iv). Ovariectomy resulted in additional increases in blood pressure in hypertensive rats and was associated with decreased vagal tone. Resistance exercise trained rats had lower mean arterial pressure than untrained rats (RTHO: 159±2.2 vs SHO: 177±3.4 mmHg), as well as resting bradycardia (RTHO: 332±9.0 vs SHO: 356±5 bpm). Sympathetic tone was also lower in the trained group. Moreover, sympathetic tone was positively correlated with resting HR (r=0.7, P<0.05). The additional arterial pressure increase in hypertensive rats caused by ovarian hormone deprivation was attenuated by moderate-intensity dynamic resistance training. This benefit may be associated with resting bradycardia and reduced cardiac sympathetic tone after training, which suggests potential benefits of resistance exercise for the management of hypertension after ovarian hormone deprivation.
authors.affiliation: Laboratório de Fisiologia Translacional, Programa de Ciências da Reabilitação, Universidade Nove de Julho, São Paulo, SP, Brasil.
authors.forename: G L
authors.initials: GL
authors.lastname: Shimojo
authors.affiliation: Laboratório de Fisiologia Translacional, Programa de Ciências da Reabilitação, Universidade Nove de Julho, São Paulo, SP, Brasil.
authors.forename: R K
authors.initials: RK
authors.lastname: Palma
authors.affiliation: Laboratório de Fisiologia Translacional, Programa de Ciências da Reabilitação, Universidade Nove de Julho, São Paulo, SP, Brasil.
authors.forename: J O
authors.initials: JO
authors.lastname: Brito
authors.affiliation: Laboratório de Fisiologia Translacional, Programa de Ciências da Reabilitação, Universidade Nove de Julho, São Paulo, SP, Brasil.
authors.forename: I C
authors.initials: IC
authors.lastname: Sanches
authors.affiliation: Instituto do Coração, Faculdade de Medicina, Universidade de São Paulo, São Paulo, SP, Brasil.
authors.forename: M C
authors.initials: MC
authors.lastname: Irigoyen
authors.affiliation: Laboratório de Fisiologia Translacional, Programa de Ciências da Reabilitação, Universidade Nove de Julho, São Paulo, SP, Brasil.
authors.forename: K
authors.initials: K
authors.lastname: De Angelis
mesh_terms: D000818:Animals; D000959:Antihypertensive Agents / Q000494:pharmacology; D001286:Atropine Derivatives / Q000494:pharmacology; D001341:Autonomic Nervous System / Q000187:drug effects / Q000502:physiology*; D001835:Body Weight; D001919:Bradycardia / Q000503:physiopathology / Q000517:prevention & control; D005260:Female; D006439:Hemodynamics / Q000187:drug effects / Q000502:physiology*; D006973:Hypertension / Q000188:drug therapy / Q000503:physiopathology*; D008593:Menopause / Q000502:physiology; D010052:Ovariectomy; D010276:Parasympatholytics / Q000494:pharmacology; D010805:Physical Conditioning, Animal / Q000502:physiology*; D011433:Propranolol / Q000494:pharmacology; D011918:Rats, Inbred SHR; D017208:Rats, Wistar; D015203:Reproducibility of Results; D055070:Resistance Training / Q000379:methods*; D013997:Time Factors
chemical_list: D000959:Antihypertensive Agents; D001286:Atropine Derivatives; D010276:Parasympatholytics; C006649:methylatropine; D011433:Propranolol
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