title: The effect of aerobic physical training on cardiac autonomic control of rats submitted to ovariectomy.
abstract: OBJECTIVE
  To investigate the effect of aerobic physical training on cardiovascular autonomic control in ovariectomized rats using different approaches.
  
  
  METHODS
  Female Wistar rats were divided into four groups: sedentary sham rats (group SSR), trained sham rats(group TSR), sedentary ovariectomized rats (group SOR), and trained ovariectomized rats (group TOR). Animals from the trained groups were submitted to a physical training protocol (swimming) for 12 weeks.
  
  
  RESULTS
  Pharmacological evaluation showed that animals from group TSR had an increase in their cardiac vagal tonus compared with the animals from groups SSR and SOR. The analysis of heart rate variability (HRV) showed that groups TSR and SOR had fewer low-frequency oscillations (0.20-0.75 Hz) compared with groups SSR and TOR.When groups TSR and SOR were compared, the former was found to have fewer oscillations. With regard to high frequency oscillations (0.75-2.5 Hz), group SSR had a reduction compared with the other groups, whereas group TSR had the greatest oscillation compared with groups SOR and TOR, with all values expressed in normalized units.Analysis of HRV was performed after pharmacological blockade, and low-frequency oscillations were found to be predominantly sympathetic in sedentary animals, whereas there was no predominance in trained animals.
  
  
  CONCLUSIONS
  Ovariectomy did not change the tonic autonomic control of the heart and, in addition, reduced the participation of sympathetic component in cardiac modulation. Physical training, on the other hand, increased the participation of parasympathetic modulation on the HRV, including ovariectomized rats.
authors.affiliation: Exercise Physiology Laboratory, Department of Biomechanics, Medicine, and Rehabilitation, Ribeirão Preto School of Medicine, University of São Paulo, São Paulo, Brazil.
authors.forename: Geisa C S V
authors.initials: GC
authors.lastname: Tezini
authors.forename: Larissa C R
authors.initials: LC
authors.lastname: Silveira
authors.forename: Paula G
authors.initials: PG
authors.lastname: Villa-Clé
authors.forename: Cynthia P
authors.initials: CP
authors.lastname: Jacinto
authors.forename: Thaisa H R
authors.initials: TH
authors.lastname: Di Sacco
authors.forename: Hugo C D
authors.initials: HC
authors.lastname: Souza
mesh_terms: D000319:Adrenergic beta-Antagonists / Q000494:pharmacology; D000332:Aerobiosis; D000818:Animals; D001286:Atropine Derivatives / Q000494:pharmacology; D001341:Autonomic Nervous System / Q000502:physiology*; D001794:Blood Pressure / Q000502:physiology; D005260:Female; D006321:Heart / Q000294:innervation*; D006339:Heart Rate / Q000502:physiology; D010052:Ovariectomy; D010276:Parasympatholytics / Q000494:pharmacology; D010805:Physical Conditioning, Animal / Q000502:physiology*; D011433:Propranolol / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D014630:Vagus Nerve / Q000502:physiology
chemical_list: D000319:Adrenergic beta-Antagonists; D001286:Atropine Derivatives; D010276:Parasympatholytics; C006649:methylatropine; D011433:Propranolol