Voluntary physical exercise-induced vascular effects in spontaneously hypertensive rats.
Forced training has been shown to have beneficial vascular effects in various animal exercise models. In the present study, we explored possible physiological and molecular effects of voluntary physical exercise on various vascular beds. SHR (spontaneously hypertensive rats) performed voluntary exercise for 5 weeks in a computerized wheel cage facility. Ex vivo myograph studies revealed an increased sensitivity of the ACh (acetylcholine)-mediated vasodilation in resistance arteries of the exercised animals (ED50=15.0+/-3.5 nmol/l) compared with the controls (ED50=37.0+/-8.8 nmol/l; P=0.05). The exercise/control difference was abolished after scavenging reactive oxygen radicals. In conduit arteries, ACh induced a similar vasodilatory response in both groups. The in vivo aortic wall stiffness, assessed by means of Doppler tissue echography, was significantly lower in the exercising animals than in controls. This was demonstrated by significantly increased peak systolic aortic wall velocity (P=0.03) and the velocity time integral (P=0.01) in exercising animals compared with controls. The relative gene expression of eNOS (endothelial nitric oxide synthase) was similar in both groups of animals, whereas Cu/ZnSOD (copper/zinc superoxide dismutase) gene expression was significantly increased (+111%; P=0.0007) in the exercising animal compared with controls. In conclusion, voluntary physical exercise differentially improves vascular function in various vascular beds. Increased vascular compliance and antioxidative capacity may contribute to the atheroprotective effects associated with physical exercise in conduit vessels.
Department of Physiology, Institute of Physiology and Pharmacology, Göteborg University, Göteborg, Sweden.
Ulrika
U
Hägg
Irene
I
Andersson
Andrew S
AS
Naylor
Julia
J
Grönros
Ingibjörg H
IH
Jonsdottir
Göran
G
Bergström
Li-ming
LM
Gan
D000818:Animals; D001013:Aorta, Thoracic / Q000000981:diagnostic imaging / Q000503:physiopathology; D001794:Blood Pressure; D001835:Body Weight; D015150:Echocardiography, Doppler / Q000379:methods; D004730:Endothelium, Vascular / Q000503:physiopathology*; D015971:Gene Expression Regulation, Enzymologic; D006973:Hypertension / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology*; D008638:Mesenteric Arteries / Q000503:physiopathology; D009043:Motor Activity; D009206:Myocardium / Q000473:pathology; D009569:Nitric Oxide / Q000502:physiology; D019001:Nitric Oxide Synthase / Q000235:genetics / Q000378:metabolism; D009929:Organ Size; D005082:Physical Exertion; D051381:Rats; D011918:Rats, Inbred SHR; D013482:Superoxide Dismutase / Q000235:genetics / Q000378:metabolism; D014664:Vasodilation
D009569:Nitric Oxide; D019001:Nitric Oxide Synthase; D013482:Superoxide Dismutase