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Physical training restores the increased pressor and chronotropic responses intensity‐induced by acute exercise in rats fed with hypercaloric diet
Author(s) -
Lima Daniel Carvalho,
Guimarães Juliana Bohenen,
Rodovalho Gisele Vieira,
Silveira Simonton Andrade,
Haibara Andrea Siqueira,
Coimbra Cândido Celso
Publication year - 2010
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.24.1_supplement.623.7
Subject(s) - chronotropic , medicine , baroreflex , heart rate , endocrinology , blood pressure , weaning , treadmill
We have showed that hypercaloric diet induces an autonomic imbalance with reduced baroreflex sensitivity. The present study assessed the effect of exercise training on cardiac autonomic balance and cardiovascular adjustments induced by exercise in rats fed with hypercaloric diet. Male Wistar rats (weaning) were treated with hypercaloric diet (68%, Cho; 16%, Ptn) and submitted or not to exercise training in a treadmill (HD, n=10; HDT, n=9) during 9 weeks. Animals treated with chow diet (CD, n=11; 57% Cho; 30% Ptn) were used as control group. After training, we evaluate cardiac autonomic balance (methylatropine, 3 mg/Kg and propanolol, 4 mg/Kg) that showed an increased sympathetic tonus in HD (75%) and in HDT (104%). We also evaluated cardiovascular adjustments during submaximal exercise and we observed an increased pressor adjustment in HD that was attenuated by training (p<0.05). In adittion, the chronotropic adjustment was reduced in HDT (p<0.05). Midpoint, threshold pressure, saturation pressure and operating range were increased in HD by about 62%, 44%, 72% and 111%, respectively. However, maximal response of heart rate was attenuated in HDT (33%), as well as, threshold pressure (41%). In summary, exercise training improves the autonomic activity in response to exercise, restoring the increased cardiovascular responses in rats fed with hypercaloric diet. Financial support: CAPES, CNPq and FAPEMIG.