Exercise training improves arterial baro- and chemoreflex in control and diabetic rats.

Abstract

We investigated the effect of exercise training on blood pressure, heart rate, and arterial baro- and chemoreflex sensitivity in diabetic rats (streptozotocin, 50 mg/kg iv). Male Wistar rats (251+/-10 g) were divided into 4 groups (n=8, each group): sedentary normotensive (SC), sedentary diabetic (SD), trained normotensive (TC), and trained diabetic (TD). Trained groups underwent exercise training on a treadmill (10 weeks). Exercise training induced resting bradycardia (340+/-5 vs. 316+/-8 bpm) and improvement in baroreflex tachycardic response (3.4+/-0.31 vs. 2.7+/-0.06 bpm/mmHg in SC) and chemoreflex bradycardic (145+/-12 vs. 78+/-7 bpm in SC) and pressor (49+/-5 vs. 22+/-3 mmHg in SC) responses in control rats. Diabetic-induced hypotension (SC: 107+/-2 vs. SD: 93+/-2 mmHg) and bradycardia (SC: 340+/-5 vs. SD: 276+/-7 bpm) were reversed by exercise training. Baroreflex tachycardic and bradycardic responses impaired in SD rats (SD: 2.1+/-0.18 and 1.3+/-0.08 vs. SC: 2.7+/-0.06 and 1.3+/-0.08 bpm/mmHg) were enhanced in TD rats (2.5+/-0.1 and 1.7+/-0.06 bpm/mmHg). Chemoreflex bradycardic and pressor responses, attenuated in SD rats (23+/-9 bpm and 7+/-1 mmHg) in relation to SC rats, were improved by exercise (TD: 84+/-15 bpm and 32+/-5 mmHg). The improvement in arterial baro- and chemoreflex-mediated control of circulation in trained control and diabetic rats reinforces the role of exercise in the management of cardiovascular risk in healthy and diabetic individuals.

• Authors: Angela D Harthmann, Kátia De Angelis, Luciana Parente Costa, Danielle Senador, Beatriz D Schaan, Eduardo Moacyr Krieger, Maria-Cláudia Irigoyen
• Journal: Autonomic neuroscience : basic & clinical (Auton Neurosci) Vol. 133 Issue 2 Pg. 115-20 (May 30 2007) ISSN: 1566-0702 [Print] Netherlands
• PMID: 17196889 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Topics

• Animals
• Autonomic Nervous System Diseases (etiology, physiopathology, therapy)
• Baroreflex (physiology)
• Blood Pressure (physiology)
• Bradycardia (physiopathology)
• Cardiovascular Diseases (physiopathology, prevention & control, therapy)
• Chemoreceptor Cells (physiology)
• Diabetes Complications (physiopathology, prevention & control, therapy)
• Diabetes Mellitus, Experimental
• Exercise Test (methods)
• Exercise Therapy (methods)
• Heart Rate (physiology)
• Male
• Physical Conditioning, Animal (physiology)
• Rats
• Recovery of Function (physiology)
• Tachycardia (physiopathology)
• Treatment Outcome