TABLE 1

Villin-adjusted kinetics of pooled microsomal quercetin glucuronidation in the small intestine of male F344 rats

Data are modeled by Michaelis-Menten kinetics and are expressed as the estimate ± S.E. of duplicate determinations.

Isomer and Segment	Age	V_max	K_m	CL_int
	mo	nmol · min⁻¹ · mg⁻¹/villin	μM	ml · min⁻¹ · mg⁻¹/villin
7-O-Glucuronide
Proximal	4	0.086 ± 0.007	2.67 ± 0.97	0.0321
	12	0.496 ± 0.038	3.13 ± 1.10	0.159
	18	1.41 ± 0.15	3.16 ± 1.45	0.446
	28	0.330 ± 0.044	3.77 ± 2.15	0.0873
Medial	4	2.53 ± 0.13	5.34 ± 1.71	0.473
	12	2.99 ± 0.17	2.35 ± 1.19	1.27
	18	4.24 ± 0.23	3.81 ± 1.48	1.11
	28	1.37 ± 0.07	5.10 ± 1.56	0.268
Distal	4	4.29 ± 0.14	6.06 ± 1.14	0.707
	12	19.3 ± 0.7	13.7 ± 2.3	1.41
	18	20.4 ± 0.5	14.0 ± 1.7	1.46
	28	5.81 ± 0.18	9.45 ± 1.48	0.615
3-O-Glucuronide
Proximal	4	0.039 ± 0.001	0.45 ± 0.12	0.0862
	12	0.202 ± 0.012	0.83 ± 0.30	0.244
	18	0.569 ± 0.062	1.62 ± 0.90	0.352
	28	0.130 ± 0.014	1.58 ± 0.89	0.0825
Medial	4	0.884 ± 0.053	3.85 ± 1.64	0.229
	12	1.06 ± 0.07	1.51 ± 1.10	0.701
	18	1.46 ± 0.10	2.37 ± 1.40	0.615
	28	0.498 ± 0.024	3.92 ± 1.30	0.127
Distal	4	1.42 ± 0.06	4.92 ± 1.26	0.288
	12	5.88 ± 0.22	10.8 ± 1.9	0.547
	18	6.08 ± 0.24	10.7 ± 2.0	0.571
	28	1.78 ± 0.08	7.04 ± 1.84	0.253
4′-O-Glucuronide
Proximal	4	0.134 ± 0.007	2.97 ± 0.70	0.0452
	12	0.723 ± 0.080	3.70 ± 1.76	0.1954
	18	1.78 ± 0.15	5.65 ± 1.80	0.3154
	28	0.358 ± 0.041	5.14 ± 2.34	0.0697
Medial	4	1.56 ± 0.09	15.2 ± 3.8	0.102
	12	1.90 ± 0.11	6.81 ± 2.30	0.279
	18	2.47 ± 0.14	9.12 ± 2.66	0.271
	28	0.819 ± 0.067	15.1 ± 5.3	0.054
Distal	4	1.65 ± 0.06	13.2 ± 2.2	0.125
	12	4.50 ± 0.27	15.7 ± 4.0	0.286
	18	5.94 ± 0.17	14.0 ± 1.8	0.424
	28	1.92 ± 0.05	14.0 ± 1.5	0.137
3′-O-Glucuronide
Proximal	4	0.146 ± 0.007	8.08 ± 1.36	0.0180
	12	0.763 ± 0.054	12.4 ± 2.8	0.0617
	18	2.01 ± 0.17	10.0 ± 2.9	0.2008
	28	0.426 ± 0.038	10.9 ± 3.2	0.0390
Medial	4	2.13 ± 0.05	27.6 ± 2.3	0.077
	12	2.75 ± 0.08	15.0 ± 1.9	0.183
	18	3.55 ± 0.12	15.9 ± 2.2	0.223
	28	1.08 ± 0.07	19.3 ± 4.8	0.056
Distal	4	2.59 ± 0.11	23.1 ± 3.5	0.112
	12	9.76 ± 0.80	37.3 ± 9.6	0.262
	18	12.3 ± 0.5	37.8 ± 5.2	0.326
	28	4.00 ± 0.17	39.9 ± 5.3	0.100