Training does not affect the alteration in pulmonary artery vasoreactivity in pulmonary hypertensive rats.
This study examined the effects of training on intrinsic vasorelaxation and vasoconstriction properties of pulmonary hypertensive rat arteries. Fifty seven male Wistar rats were randomly assigned to 4 groups: normotensive sedentary (n = 14), normotensive trained (n = 15), pulmonary hypertensive sedentary (n = 15) and pulmonary hypertensive trained (n = 13). Pulmonary hypertension was obtained using a chronic hypoxia exposure model. Endothelium-dependent vasorelaxation to acetylcholine (10(-8)-10(-4) M), endothelium-independent vasorelaxation to sodium nitro-prusside (10(-8)-10(-4) M), and vasoconstriction to epinephrine (10(-9)-10(-4) M) and endothelin-1 (10(-12)-10(-7) M) were assessed on isolated rings of large pulmonary arteries. Alterations in endothelium-dependent and -independent vasorelaxation properties as well as enhanced vasoconstrictor responses were obtained in pulmonary hypertensive rats. Chronic exercise did not affect those pulmonary vasoreactivity alterations. A predominant effect of chronic hypoxia over training seems to be partially responsible for this phenomenon, probably through impairment in nitric oxide bioavailability and vascular smooth muscle sensitivity.
Goret
Lucie
L
EA2992, Dynamique des Incohérences Cardio-Vasculaires, Faculté de Médecine de Nîmes, Montpellier, France.
Reboul
Cyril
C
Tanguy
Stephane
S
Dauzat
Michel
M
Obert
Philippe
P
D000109:Acetylcholine / Q000494:pharmacology; D000818:Animals; D004305:Dose-Response Relationship, Drug; D019332:Endothelin-1 / Q000494:pharmacology; D004730:Endothelium, Vascular / Q000502:physiology; D004837:Epinephrine / Q000494:pharmacology; D006976:Hypertension, Pulmonary / Q000503:physiopathology*; D000860:Hypoxia / Q000503:physiopathology; D066298:In Vitro Techniques; D008297:Male; D009599:Nitroprusside / Q000494:pharmacology; D010805:Physical Conditioning, Animal / Q000502:physiology*; D011189:Potassium Chloride / Q000494:pharmacology; D011651:Pulmonary Artery / Q000503:physiopathology*; D011897:Random Allocation; D051381:Rats; D017208:Rats, Wistar; D014661:Vasoconstriction / Q000187:drug effects / Q000502:physiology*; D014662:Vasoconstrictor Agents / Q000494:pharmacology; D014664:Vasodilation / Q000187:drug effects / Q000502:physiology; D014665:Vasodilator Agents / Q000494:pharmacology
D019332:Endothelin-1; D014662:Vasoconstrictor Agents; D014665:Vasodilator Agents; D009599:Nitroprusside; D011189:Potassium Chloride; D000109:Acetylcholine; D004837:Epinephrine