Stimulation of in vitro angiogenesis by tetrahydrobiopterin in bovine aortic endothelial cells

This study examined whether tetrahydrobiopterin (BH4) stimulates angiogenes is by measuring the formation of tube-like structures in vascular endotheli al cells. Bovine aortic endothelial cells that were cultured between two la yers of collagen type I gel formed tube-like networks. Addition of BH4 or s epiapterin, a precursor of BH4 synthesis, stimulated the formation of tube- like structures. The sepiapterin-stimulated tube formation was completely i nhibited by co-treatment with N-acetylserotonin, an inhibitor of sepiapteri n reductase. These findings show that BH4 stimulates in vitro angiogenesis in vascular endothelial cells.