Glucuronidation of 1-naphthol in nuclear and microsomal fractions of the human intestine.
The glucuronyl transferase activity was measured with 1-naphthol as a substrate in nuclear and microsomal fractions of the human intestinal mucosa. The mucosa was obtained from different parts of the intestine. The rate of 1-naphthol glucuronidation ranged between 0.70 and 1.26 nmol/mg/min (nuclear fraction) and 0.21 and 0.54 nmol/mg/min (microsomal fraction). The average (+/- SEM) of the nuclear/microsomal ratios of the glucuronyl transferase was 2.48 +/- 0.19. The epoxide hydrolase activity towards styrene oxide was measured in the same subcellular fractions; it was undetectable in the nuclear fraction, whereas it was 0.46 +/- 0.04 nmol/mg/min (mean +/- SEM) in the microsomal fraction. The glucuronyl transferase activity was also measured in nuclear and microsomal fractions of the human liver. The activity (mean +/- SEM) was 1.14 +/- 0.21 nmol/mg/min (nuclei) and 5.00 +/- 0.80 (microsomes). The average of the nuclear to microsomal ratios (mean +/- SEM) was 0.32 +/- 0.03.
D000368:Aged; D002467:Cell Nucleus / Q000201:enzymology*; D004851:Epoxide Hydrolases / Q000032:analysis; D005260:Female; D014453:Glucuronosyltransferase / Q000032:analysis*; D006801:Humans; D007422:Intestines / Q000201:enzymology*; D008297:Male; D008861:Microsomes / Q000201:enzymology*; D008875:Middle Aged; D009284:Naphthols / Q000378:metabolism*
D009284:Naphthols; C029350:1-naphthol; D014453:Glucuronosyltransferase; D004851:Epoxide Hydrolases