Abstract | OBJECTIVES: METHODS: Vascular segments of saphenous veins were obtained from 17 patients undergoing elective coronary artery bypass grafting, and in vitro endothelium-dependent and endothelium-independent responses to acetylcholine and sodium nitroprusside were assessed. Isometric dose-response curves were constructed in precontracted rings in the presence and absence of tetrahydrobiopterin (0.1 mmol/L) with the use of the organ bath apparatus. The percentages of maximum relaxation and sensitivity were compared between interventions. RESULTS:
Acetylcholine caused dose-dependent endothelium-mediated relaxation in saphenous veins. In the presence of tetrahydrobiopterin, acetylcholine-induced relaxation was significantly augmented (percentage maximum relaxation, 16.8% +/- 2.9% vs control 7.5% +/- 1.8%; P =.003) without an effect on agonist sensitivity. These effects were endothelium-specific because endothelium-independent responses to sodium nitroprusside were preserved. CONCLUSIONS: These data uncover beneficial effects of acute tetrahydrobiopterin addition on endothelial function in human vessels. Because endothelial dysfunction has been implicated in the development of graft failure, studies aimed at chronic delivery of tetrahydrobiopterin would be useful in determining the contribution of this cofactor toward saphenous vein atherosclerosis.
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Authors | S Verma, F Lovren, A S Dumont, K J Mather, A Maitland, T M Kieser, C R Triggle, T J Anderson |
Journal | The Journal of thoracic and cardiovascular surgery
(J Thorac Cardiovasc Surg)
Vol. 120
Issue 4
Pg. 668-71
(Oct 2000)
ISSN: 0022-5223 [Print] United States |
PMID | 11003746
(Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
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Chemical References |
- Antioxidants
- Vasodilator Agents
- Nitroprusside
- Biopterin
- sapropterin
- Acetylcholine
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Topics |
- Acetylcholine
(pharmacology)
- Analysis of Variance
- Antioxidants
(pharmacology)
- Biopterin
(analogs & derivatives, pharmacology)
- Coronary Artery Bypass
- Dose-Response Relationship, Drug
- Endothelium, Vascular
(drug effects)
- Humans
- In Vitro Techniques
- Nitroprusside
(pharmacology)
- Saphenous Vein
(drug effects)
- Vasodilation
(drug effects)
- Vasodilator Agents
(pharmacology)
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