INDUCTION AND IMMUNOLOGICAL CHARACTERIZATION OF THE URIDINE DIPHOSPHATE-GLUCURONOSYLTRANSFERASE CONJUGATING 1-NAPHTHOL IN THE RAT CHOROID-PLEXUS

The uridine diphosphate-glucuronosyltransferase isoform conjugating l- naphthol has a very high activity in the rat choroid plexus. We showed that antibodies raised against the main liver isoenzyme cross-reacted with a choroidal protein exhibiting the same molecular weight as the hepatic form. Both enzymes had a similar affinity for l-naphthol. Afte r an in vivo treatment by 3-methylcholanthrene, a 3-fold increase of t he activity in both the liver and choroid plexuses was observed. These results suggest that the choroidal and hepatic enzymes conjugating l- naphthol are identical. This high metabolic activity suggests a metabo lic protection of the brain by the choroid plexus.