Exercise training improves arterial baro- and chemoreflex in control and diabetic rats.
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.
Harthmann
Angela D
AD
Hypertension Unit, Heart Institute (InCor), University of São Paulo, Medical School, Av. Enéas de Carvalho Aguiar 44, São Paulo, SP 05403-000, Brazil.
De Angelis
Kátia
K
Costa
Luciana Parente
LP
Senador
Danielle
D
Schaan
Beatriz D
BD
Krieger
Eduardo Moacyr
EM
Irigoyen
Maria-Cláudia
MC
D000818:Animals; D001342:Autonomic Nervous System Diseases / Q000209:etiology / Q000503:physiopathology / Q000628:therapy*; D017704:Baroreflex / Q000502:physiology*; D001794:Blood Pressure / Q000502:physiology; D001919:Bradycardia / Q000503:physiopathology; D002318:Cardiovascular Diseases / Q000503:physiopathology / Q000517:prevention & control / Q000628:therapy*; D002628:Chemoreceptor Cells / Q000502:physiology*; D048909:Diabetes Complications / Q000503:physiopathology / Q000517:prevention & control / Q000628:therapy*; D003921:Diabetes Mellitus, Experimental; D005080:Exercise Test / Q000379:methods; D005081:Exercise Therapy / Q000379:methods; D006339:Heart Rate / Q000502:physiology; D008297:Male; D010805:Physical Conditioning, Animal / Q000502:physiology*; D051381:Rats; D020127:Recovery of Function / Q000502:physiology; D013610:Tachycardia / Q000503:physiopathology; D016896:Treatment Outcome