TABLE 4

ugt-Catalyzed reactions: Michaelis-Menten parameters for the formation of M3G, E3G, and E17G in control mouse, SC, and SCKO liver microsomes

Metabolite (Isozyme)
Vmaxa (nmol/min · mg)
Kma (μM)
Vmax/Km (μl/min · mg)
In Vivo Cl′int (ml/min/g of body weight)
M3G (ugt2b)
    Control 18.90 ± 0.6 276.6 ± 39.4 67.5 0.23
    SC 25.11 ± 0.43* 269.9 ± 20.3 93.0 0.26
    SCKO 27.06 ± 1.12* 19.7 ± 36.0 140.2 0.30
E3G (ugt1a1)
    Control 7.01 ± 0.73 190.64 ± 40.9 36.8 0.12
    SC 5.02 ± 0.57 159.13 ± 32.5 31.5 0.09
    SCKO 3.46 ± 0.28* 136.8 ± 21.3 25.3 0.05
E17G (ugt1a, 2b)
    Control 0.71 ± 0.09 60.4 ± 19.2 11.75 0.04
    SC 0.21 ± 0.01* 26.2 ± 2.3 8.0 0.02
    SCKO
0.32 ± 0.03*
29.6 ± 8.6
10.8
0.02

  • ↵ a Data expressed as parameter estimate ± S.E. (n = 6).

  • ↵* Values were significantly different than corresponding control values, as determined by a two-sided t test (p < 0.01).