
Rapid clearance of supplemented tetrahydrobiopterin is driven by high-capacity transporters in the kidney
Keywords: BH4, tetrahydrobiopterin; 6RBH4, (6R)-L-erythro-5,6,7,8-tetrahydrobiopterin dihydrochloride; BH2, 7,8-dihydrobiopterin; BP, tissue biopterin (BH2 + BH4) including a trace of fully oxidized biopterin; CsA, cyclosporin A; RBC, red blood cellTetrahydrobiopte