... glucuronate. Interestingly, vitamin C for- mation is induced in Gunn rats by phenobarbital [8],an inducer of UGT2s, which is indirect evidence for the involvement of members of the UGT2 family.To the ... 1523were performed in the presence of sorbinil, an inhibitor of aldose reductase and aldehyde reductase [9], toblock the conversion of glucuronate to l-gulonate, and in the presence of UDP-N-acetylglucosamine(UDPGlcNAc), ... test whether the enzymes catalysing the forma-tion of glucuronate and glucuronate 1-phosphate werepresent in the lumen of the ER (or had their catalyticsite oriented towards the lumen of this...