This Article Full Text Full Text (PDF) All Versions of this Article: 46/4/998    most recent 01.HYP.0000176238.90688.6bv1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Irigoyen, M.-C. Articles by De Angelis, K. Search for Related Content PubMed PubMed Citation Articles by Irigoyen, M.-C. Articles by De Angelis, K. Pubmed/NCBI databases Substance via MeSH Related Collections Animal models of human disease Other hypertension Hypertension - basic studies Exercise/exercise testing/rehabilitation

(Hypertension. 2005;46:998.)
© 2005 American Heart Association, Inc.

Part 2 Original Articles

Exercise Training Improves Baroreflex Sensitivity Associated With Oxidative Stress Reduction in Ovariectomized Rats

Maria-Cláudia Irigoyen; Janaina Paulini; Lucinar J. F. Flores; Karin Flues; Mariane Bertagnolli; Edson Dias Moreira; Fernanda Consolim-Colombo; Adriane Belló-Klein; Kátia De Angelis

From the Hypertension Unit (M.-C.I., J.P., K.F., E.D.M., F.C.-C.), Heart Institute (InCor), University of Sao Paulo Medical School, Sao Paulo; the Laboratory of Cardiovascular Physiology (M.-C.I., M.B., A.B.-K.), Department of Physiology, Basic and Health Science Institute, Federal University of Rio Grande do Sul, Porto Alegre; and the Human Movement Laboratory (L.J.F.F., K.D.A.), Sao Judas Tadeu University, Sao Paulo, Brazil.

Correspondence to Kátia De Angelis, PhD, Human Movement Laboratory, Sao Judas Tadeu University, Av Taquari 546, Sao Paulo, Brazil 03166-000. prof.kangelis{at}usjt.br

The protection from coronary events that young women have is sharply reduced at menopause. Oxidative stress and baroreflex sensitivity impairment of the circulation have been demonstrated to increase cardiovascular risk. On the other hand, exercise training has been indicated as a nonpharmacological treatment for many diseases. The aim of the present study was to test the hypothesis that exercise training can improve baroreflex sensitivity associated with reduction in oxidative stress in ovariectomized rats, an experimental model of menopause. Exercise training was performed on a treadmill for 8 weeks. Arterial pressure and baroreflex sensitivity, which were evaluated by tachycardic and bradycardic responses to changes in arterial pressure, were monitored. Oxidative stress was evaluated by chemiluminescence and superoxide dismutase and catalase antioxidant enzyme activities. Exercise training reduced resting mean arterial pressure (112±2 vs 122±3 mm Hg in the sedentary group) and heart rate (325±4 vs 356±12 bpm in the sedentary group) and also improved baroreflex sensitivity (tachycardic response, 63% and bradycardic response, 58%). Myocardium (25%) and gastrocnemius muscle (48%) chemiluminescence were reduced, and myocardial superoxide dismutase (44%) and gastrocnemius catalase (97%) activities were enhanced in trained rats in comparison with sedentary rats. Myocardium chemiluminescence was positively correlated with systolic arterial pressure (r=0.6) and inversely correlated with baroreflex sensitivity (tachycardic response, r=–0.8 and bradycardic response, r=–0.7). These results indicate that exercise training in ovariectomized rats improves resting hemodynamic status and reflex control of the circulation, probably associated with oxidative stress reduction, suggesting a homeostatic role for exercise training in reducing cardiovascular risk in postmenopausal women.

Key Words: exercise • baroreflex • oxidative stress • rat • estrogen • menopause

This article has been cited by other articles:

				S. B.C. Souza, K. Flues, J. Paulini, C. Mostarda, B. Rodrigues, L. E. Souza, M.-C. Irigoyen, and K. De Angelis Role of Exercise Training in Cardiovascular Autonomic Dysfunction and Mortality in Diabetic Ovariectomized Rats Hypertension, October 1, 2007; 50(4): 786 - 791. [Abstract] [Full Text] [PDF]

				Y.-X. Pan, L. Gao, W.-Z. Wang, H. Zheng, D. Liu, K. P. Patel, I. H. Zucker, and W. Wang Exercise Training Prevents Arterial Baroreflex Dysfunction in Rats Treated With Central Angiotensin II Hypertension, March 1, 2007; 49(3): 519 - 527. [Abstract] [Full Text] [PDF]