1. Effect of training frequency on endothelium-dependent vasorelaxation in rats
- Author
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Jacques Mansourati, Michael Theron, François Guerrero, E. Heylen, B. Saïag, Sanéo Thioub, Optimisation des régulations physiologiques (ORPHY (EA 4324)), Institut Brestois Santé Agro Matière (IBSAM), and Université de Brest (UBO)-Université de Brest (UBO)-Université de Brest (UBO)-Centre Hospitalier Régional Universitaire de Brest (CHRU Brest)
- Subjects
Male ,MESH: Phenylephrine ,Arginine ,Epidemiology ,MESH: Random Allocation ,Indomethacin ,Vasodilation ,MESH: Physical Conditioning, Animal ,030204 cardiovascular system & hematology ,MESH: Dose-Response Relationship, Drug ,Phenylephrine ,Random Allocation ,MESH: NG-Nitroarginine Methyl Ester ,0302 clinical medicine ,rat ,MESH: Animals ,MESH: Indomethacin ,0303 health sciences ,Tetraethylammonium ,3. Good health ,NG-Nitroarginine Methyl Ester ,medicine.anatomical_structure ,Anesthesia ,MESH: Citrate (si)-Synthase ,MESH: Endothelium, Vascular ,Sodium nitroprusside ,Cardiology and Cardiovascular Medicine ,Acetylcholine ,medicine.drug ,Nitroprusside ,medicine.medical_specialty ,endothelium ,MESH: Rats ,Endothelium ,Citrate (si)-Synthase ,Endothelium dependent ,NO ,MESH: Vasodilation ,03 medical and health sciences ,EDHF ,Physical Conditioning, Animal ,MESH: Analysis of Variance ,Internal medicine ,medicine.artery ,[SDV.MHEP.PHY]Life Sciences [q-bio]/Human health and pathology/Tissues and Organs [q-bio.TO] ,medicine ,Animals ,Rats, Wistar ,030304 developmental biology ,Analysis of Variance ,Aorta ,Dose-Response Relationship, Drug ,MESH: Acetylcholine ,business.industry ,COX ,MESH: Rats, Wistar ,biochemical phenomena, metabolism, and nutrition ,acetylcholine ,MESH: Male ,MESH: Nitroprusside ,Rats ,aorta ,Endocrinology ,MESH: Tetraethylammonium ,Endothelium, Vascular ,business ,exercise training - Abstract
International audience; BACKGROUND: Moderate physical activity enhances endothelium-dependent vasorelaxation. Whether the frequency of exercise affects endothelial function is unclear. The purpose of this study was to investigate the effects of various frequencies of training on endothelium-dependent vasorelaxation. DESIGN: Male Wistar rats were trained for 8 weeks on a treadmill at various frequencies [1 (Ex1), 3 (Ex3) or 5 days/week (Ex5)] and compared with age-matched sedentary animals (SED). A control group allowed us to assess endothelial function before the exercise protocol. Rings of thoracic aorta were precontracted with phenylephrine. RESULTS: Endothelium-independent relaxation elicited by sodium nitroprusside was similar in all groups. The maximal response elicited by acetylcholine (ACh) was not different between groups, whereas pD2 values (-logEC50, EC50 being the concentration of ACh that elicited 50% of the maximal response) significantly correlated with frequency of training. nitro-L-arginine methyl ester (L-NAME) reduced the relaxation elicited by 10(-7) mol/l ACh or higher in control and all trained groups, and by 10(-6) mol/l ACh or higher in SED group. Indomethacin inhibited the vasodilating response to 10(-7) mol/l ACh or higher in control, SED and Ex1 groups, and to 10(-8) mol/l or more in Ex3 and Ex5 animals. Tetraethylammonium attenuated the response to 10(-6) mol/l ACh or higher in control and SED groups and to 10(-7) mol/l or more in all trained animals. CONCLUSION: This data suggest that decreased ACh-induced vasorelaxation after physical inactivity may result from impairment of endothelial nitric oxide synthase, prostacyclin and endothelium-derived hyperpolarizing factor pathways. This effect is prevented by training in a frequency-dependent manner.
- Published
- 2008