1. Effect of tetrahydrobiopterin and exercise training on endothelium-dependent vasorelaxation in SHR
- Author
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François Guerrero, Christelle Goanvec, Annie Feray, Sigrid Theunissen, Sanéo Thioub, Jacques Mansourati, Costantino Balestra, Experimental Anatomy, Optimisation des régulations physiologiques (ORPHY (EA 4324)), Institut Brestois Santé Agro Matière (IBSAM), Université de Brest (UBO)-Université de Brest (UBO)-Université de Brest (UBO)-Centre Hospitalier Régional Universitaire de Brest (CHRU Brest), Environmental & Occupational Physiology Laboratory, Haute-Ecole Paul-Henri Spaak, and Région Bretagne (Grant n° 211-B2-9/ARED)
- Subjects
Endothelial Dysfunction ,Male ,medicine.medical_specialty ,Physiology ,Blood Pressure ,Femoral artery ,Isometric exercise ,In Vitro Techniques ,030204 cardiovascular system & hematology ,Rats, Inbred WKY ,Biochemistry ,Nitric oxide ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,Physical Conditioning, Animal ,Rats, Inbred SHR ,medicine.artery ,Internal medicine ,[SDV.MHEP.PHY]Life Sciences [q-bio]/Human health and pathology/Tissues and Organs [q-bio.TO] ,medicine ,Animals ,Endothelial dysfunction ,Treadmill ,Phenylephrine ,030304 developmental biology ,computer.programming_language ,0303 health sciences ,business.industry ,sed ,General Medicine ,medicine.disease ,Biopterin ,Rats ,Femoral Artery ,Vasodilation ,Endocrinology ,chemistry ,Hypertension ,tetrahydrobiopterin ,Rat ,Endothelium, Vascular ,business ,exercise training ,computer ,Acetylcholine ,medicine.drug - Abstract
International audience; We examined whether the improvement of impaired NO-dependent vasorelaxation by exercise training could be mediated through a BH(4)-dependent mechanism. Male spontaneously hypertensive rats (SHR, n = 20) and Wistar-Kyoto rats (WKY, n = 20) were trained (Tr) for 9 weeks on a treadmill and compared to age-matched sedentary animals (Sed). Endothelium-dependent vasorelaxation (EDV) was assessed with acetylcholine by measuring isometric tension in rings of femoral artery precontracted with 10(-5) M phenylephrine. EDV was impaired in SHR-Sed as compared to WKY-Sed (p = 0.02). Training alone improved EDV in both WKY (p = 0.01) and SHR (p = 0.0001). Moreover, EDV was not different in trained SHR than in trained WKY (p = 0.934). Pretreatment of rings with L-NAME (50 μM) cancelled the difference in ACh-induced relaxation between all groups, suggesting that NO pathway is involved in these differences. The presence of 10(-5) M BH(4) in the organ bath significantly improved EDV for sedentary SHR (p = 0.030) but not WKY group (p = 0.815). Exercise training turned the beneficial effect of BH(4) on SHR to impairment of ACh-induced vasorelaxation in both SHR-Tr (p = 0.01) and WKY-Tr groups (p = 0.04). These results suggest that beneficial effect of exercise training on endothelial function is due partly to a BH(4)-dependent mechanism in established hypertension.
- Published
- 2012