Impairment on cardiac output and blood flow adjustments to exercise in L-NAME-induced hypertensive rats.
J Cardiovasc Pharmacol
; 47(3): 371-6, 2006 Mar.
Article
en En
| MEDLINE
| ID: mdl-16633078
The objective of the present study was to investigate cardiovascular adjustments at rest, during exercise, and 1 hour after exercise among nitric oxide (NO) blockade-induced hypertensive rats. Male Wistar rats (308 +/- 9 g) assigned as normotensive (n = 9) and hypertensive (N(omega)-nitro-L-arginine methyl ester, n = 11) underwent a bout of exercise. Arterial pressure (AP) and blood oxygen saturation were measured. Colored microspheres were used to evaluate blood flow and cardiac output (CO). Hypertensive rats (143 +/- 5 vs. 102 +/- 4 mmHg in normotensive rats), who presented reduced CO (57 +/- 6 vs. 102 +/- 7 mL/min in normotensive), also presented diminished blood flow in kidney, lung, and muscles at rest in comparison with normotensive rats. Exercise increased AP (20%), heart rate (40%), and CO (32%) among the normotensive rats, whereas the hypertensive rats presented an increased heart rate (40%) accompanied by a reduced venous oxygen saturation (45.5 +/- 2.1% vs. 75 +/- 0.7% in normotensive rats). Muscle vasodilatation, which was observed among the normotensive rats and is considered a hallmark adjustment to exercise, was not observed among the hypertensive rats. After a 1-hour interval from exercise most of the evaluated parameters returned to basal values. In conclusion, exercise did not cause an increase in CO, AP, or blood flow to skeletal muscle in hypertensive rats. However, it was associated with a significant increase in the arterio-venous oxygen content difference in NO-blocked rats, thus suggesting that hypertension associated with impairment in NO release induced different cardiovascular adjustments to exercise.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Condicionamiento Físico Animal
/
Gasto Cardíaco
/
Músculo Esquelético
/
Hipertensión
/
Óxido Nítrico
Límite:
Animals
Idioma:
En
Revista:
J Cardiovasc Pharmacol
Año:
2006
Tipo del documento:
Article
País de afiliación:
Brasil
Pais de publicación:
Estados Unidos