THE β-GLUCOSIDATION AND β-GLUCURONIDATION OF PANTOTHENIC ACID COMPARED WITH P-NITROPHENOL IN DOG LIVER MICROSOME

The β-glucosidation and β-glucuronidation of pantothenic acid (PaA) in dog liver microsome were compared with those of p-nitrophenol. PaA underwent β-glucosidation in the presence of uridine diphosphate glucose (UDPG). However, p-nitrophenol did not conjugate β-glucose but underwent β-glucuronidation in the presence of uridine diphosphate glucuronic acid (UDPGA). The UDP-glucuronyltransferase effect on p-nitrophenol was 1000 times larger than the UDP-glucosyltransferase effect on PaA. But no glucuronidation of PaA occurred. The optimum pH for the glucosidation of PaA was 8.5. These results indicate that PaA has a high specificity for β-glucosidation, and that β-glucosidation is an essential pathway in the metabolism of PaA in dogs.