Exercise training improves aortic depressor nerve sensitivity in rats with ischemia-induced heart failure
| Autor: | Maria S. Brasileiro-Santos, Eduardo M. Krieger, Patricia Chakur Brum, Maria Urbana P. B. Rondon, Patricia Fiorino, Holly R. Middlekauff, Edson Dias Moreira, Gustavo J. J. Silva, Carlos Eduardo Negrão, Marcele A. Coelho, Maria C. Irigoyen, E. Rondon, Katt Coelho Mattos |
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| Rok vydání: | 2006 |
| Předmět: |
Male
medicine.medical_specialty Sympathetic Nervous System Heart disease Physiology Cardiac Output Low Myocardial Ischemia Ischemia Blood Pressure Pressoreceptors Physical exercise Baroreflex Kidney Heart Rate Physical Conditioning Animal Physiology (medical) Internal medicine Animals Medicine Rats Wistar Aorta business.industry Arterial baroreflex medicine.disease Rats Autonomic nervous system Endocrinology Heart failure Circulatory system Cardiology Cardiology and Cardiovascular Medicine business Algorithms |
| Zdroj: | American Journal of Physiology-Heart and Circulatory Physiology. 291:H2801-H2806 |
| ISSN: | 1522-1539 0363-6135 |
| Popis: | Exercise training improves arterial baroreflex control in heart failure (HF) rabbits. However, the mechanisms involved in the amelioration of baroreflex control are unknown. We tested the hypothesis that exercise training would increase the afferent aortic depressor nerve activity (AODN) sensitivity in ischemic-induced HF rats. Twenty ischemic-induced HF rats were divided into trained ( n = 11) and untrained ( n = 9) groups. Nine normal control rats were also studied. Power spectral analysis of pulse interval, systolic blood pressure, renal sympathetic nerve activity (RSNA), and AODN were analyzed by means of autoregressive parametric spectral and cross-spectral algorithms. Spontaneous baroreflex sensitivity of heart rate (HR) and RSNA were analyzed during spontaneous variation of systolic blood pressure. Left ventricular end-diastolic pressure was higher in HF rats compared with that in the normal control group ( P = 0.0001). Trained HF rats had a peak oxygen uptake higher than untrained rats and similar to normal controls ( P = 0.01). Trained HF rats had lower low-frequency [1.8 ± 0.2 vs. 14.6 ± 3 normalized units (nu), P = 0.0003] and higher high-frequency (97.9 ± 0.2 vs. 85.0 ± 3 nu, P = 0.0005) components of pulse interval than untrained rats. Trained HF rats had higher spontaneous baroreceptor sensitivity of HR (1.19 ± 0.2 vs. 0.51 ± 0.1 ms/mmHg, P = 0.003) and RSNA [2.69 ± 0.4 vs. 1.29 ± 0.3 arbitrary units (au)/mmHg, P = 0.04] than untrained rats. In HF rats, exercise training increased spontaneous AODN sensitivity toward normal levels (trained HF rats, 1,791 ± 215; untrained HF rats, 1,150 ± 158; and normal control rats, 2,064 ± 327 au/mmHg, P = 0.05). In conclusion, exercise training improves AODN sensitivity in HF rats. |
| Databáze: | OpenAIRE |
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