A new assay and cellular localization for an inducible glucuronyltransferase in the embryonic chick liver.
A direct, radioisotopic assay is described for the uridine diphosphate glucuronic acid (UDPGA): p-aminophenol glucuronyltransferase. The assay uses solid phase p-aminophenol-Sephadex as the glucuronyl acceptor and UDP-[14C]GA as the glucuronyl donor. After incubation with the enzyme, the derivatized Sephadex beads are washed in SDS-urea or with high salt concentrations to remove all labeled material except for that covalently attached to the beads. Sonicated livers from chick embryos exposed to phenobarbital for at least 5 days transfer more than ten times the glucuronic acid to derivatized beads than do uninduced livers of the same developmental age. Glucuronyl-transferase activity can be detected on intact, living cells after 5 days of phenobarbital induction, whereas sonicate activity is detectable within 3 days of induction. Suspensions of living cells can show 25% the activity found in the same suspension after all the cells are lysed by sonication.
D000255:Adenosine Triphosphate / Q000494:pharmacology; D000627:Aminophenols; D000818:Animals; D002642:Chick Embryo; D003911:Dextrans; D004790:Enzyme Induction; D005966:Glucuronidase / Q000378:metabolism; D014453:Glucuronosyltransferase / Q000096:biosynthesis*; D007700:Kinetics; D008099:Liver / Q000187:drug effects / Q000201:enzymology*; D008274:Magnesium / Q000494:pharmacology; D015636:Magnesium Chloride; D008722:Methods
D000627:Aminophenols; D003911:Dextrans; D015636:Magnesium Chloride; D000255:Adenosine Triphosphate; D014453:Glucuronosyltransferase; D005966:Glucuronidase; D008274:Magnesium