Table 5

Metabolism of 5-AZU by hepatic S9 or purified xanthine oxidase from buttermilk and separate effects of allopurinol, SKF-525A, chlorpromazine, and CO-bubbling pretreatment of hepatic S9 on its metabolism

Enzyme SourceInhibitorCA Production
nmol/min/mg protein
Hepatic S910.00  ± 0.05
+1 mM allopurinol8.15  ± 0.22
+1 mM SKF-525A4.27  ± 0.25
+1 mM chlorpromazine5.68  ± 0.03
+1 mM allopurinol and SKF-525A0.02  ± 0.03
CO-treated hepatic S910.58  ± 0.59
Enzyme SourceInhibitorCA Production
nmol/min/IU
Purified xanthine oxidase389.9  ± 16.1
+1 mM allopurinol3.4  ± 0.5
+1 mM SKF-525A320.6  ± 21.2

Each value represents the means ± S.D. (n = 3).