Premium
EFFECT OF AEROBIC EXERCISE ON THE AUTONOMIC CONTROL OF HEART RATE IN RATS SUBMITTED TO L‐NAME HYPERTENSION
Author(s) -
Souza Hugo Celso Dutra,
Dias Daniel Penteado Martins,
Salgado Maria Cristina Oliveira,
Salgado Helio Ceasar,
Silva Valdo Jose Dias
Publication year - 2006
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.20.5.lb36-c
Subject(s) - heart rate , medicine , propranolol , heart rate variability , autonomic nervous system , nitric oxide , basal (medicine) , balance (ability) , cardiology , blockade , tachycardia , endocrinology , bradycardia , physical therapy , blood pressure , receptor , insulin
Hypertension induced by chronic blockade of nitric oxide synthesis with L‐NAME is characterized by autonomic imbalance with sympathetic predominance. On the other hand, physical exercise leads to cardiac autonomic imbalance with vagal predominance. The aim of this study was evaluate autonomic control of heart rate (HR) in hypertension induced by L‐NAME in rats submitted to aerobic exercise. Rats were splited into 4 groups: control, treated with L‐NAME (70 mg/kg/day, 7 days), trained by swimming during 12 weeks and trained by swimming and treated with L‐NAME in the last week. L‐NAME group presented tachycardia and hypertension as compared with other groups. Sympathovagal balance evaluated by pharmacological autonomic receptors blockade with methylatropine and propranolol also was found altered in L‐NAME group, characterizing sympathetic predominance. HR variability studied by spectral analysis showed decrease in low frequency (LF: 0.2–0.75 Hz) in L‐NAME group as compared with other groups. Sympathovagal balance was found similar between trained group as compared with control rats. However, basal HR and intrinsic heart rate was found decreased in trained rats. Exercise training did not prevent, but attenuated hypertension levels induced by L‐NAME. Moreover, L‐NAME trained group presented lower basal HR as compared with trained group, however with similar intrinsic heart rate. Support: FAPESP, FAEPA