Accumulated BH4 in mouse liver caused by administration of either 6R- or 6SBH4 consisted solely of the 6R-diastereomer: evidence of oxidation to BH2 and enzymic reduction.
Mice were given (i.p.) L-erythro-(6S)-tetrahydrobiopterin (6SBH4) or 6RBH4 and the increase in liver BH4 in both groups was almost the same. The C6-chirality of liver BH4 was determined by HPLC. After administration of 6SBH4, the liver BH4 consisted mainly of 6RBH4 (>95%). These findings show that the exogenous BH4 was oxidized to 7,8BH2 which was then taken up and enzymically reduced back to BH4 in the liver.
Sawabe
Keiko
K
Department of Biosciences, Teikyo University of Science and Technology, Uenohara, Yamanashi 409-0193, Japan. k-sawabe@st.ntu.ac.jp
Suetake
Yasuko
Y
Wakasugi
Kazunori O
KO
Hasegawa
Hiroyuki
H
D000818:Animals; D001708:Biopterins / Q000031:analogs & derivatives* / Q000737:chemistry / Q000378:metabolism; D008099:Liver / Q000378:metabolism*; D051379:Mice; D010084:Oxidation-Reduction; D013237:Stereoisomerism
D001708:Biopterins; C003402:sapropterin