Table 2.

Effect of dietary clofibrate on the NADPH-dependent oxidation of estradiol by liver microsomes from ACI rats

Treatment in diet	E2 (mg) pellet	Estradiol metabolites formed (pmol/mg protein/min)				E2 metabolized pmol/mg protein/min (%)a	E2 metabolized nmol/liver/min
		4-OH- E2	2 -OH- E2	2-OH- E1	E1
6 weeks
A. AIN-76A	0	13 ± 2	154 ± 5	20 ± 1	83 ± 11	387 ± 27 (16%)	32 ± 3
B. AIN-76A	1	18 ± 4	195 ± 22	18 ± 2	121 ± 8*	526 ± 11 (21%)	56 ± 15
C. 0.4% clofibrate	1	27 ± 3#	402 ±	42 ± 3#	140 ±	825 ± 54# (33%)	147 ± 19#
D. AIN-76A	3	14 ± 4	191 ± 18	21 ± 4	125 ±	487 ± 26 (17%)	42 ± 5
E. 0.4% clofibrate	3	34 ± 7#	427 ±	34 ± 6#	115 ± 18	835 ± 59# (33%)	155 ±18#
F. 0.4% clofibrate	0	34 ± 7*	547 ±	46 ± 6*	137 ±	989 ± 35* (40%)	181 ±12*
12 weeks
A. AIN-76A	0	13 ±2	154 ± 12	17 ± 3	93 ± 7	384 ± 24 (14%)	36 ± 9
B. AIN-76A	1	9 ± 1	150 ± 29	18 ± 3	150 ±	413 ± 30 (14%)	31 ± 3
C. 0.4% clofibrate	1	9 ± 2	368 ±	16 ± 3	97 ± 17#	638 ± 46# (22%)	113 ± 6#
D. AIN-76A	3	12 ± 2	182 ± 78	27 ± 6	157 ± 25*	404 ± 64 (16%)	40 ± 5
E. 0.4% clofibrate	3	16 ± 5	278 ± 36#	19 ± 4	66 ± 14#	606 ± 56# (16%)	95 ± 10#
F. 0.4% clofibrate	0	18 ± 5	246 ± 18*	23 ± 4	127 ± 13*	507 ± 37* (20%)	81 ± 4*
D. AIN-76A	3	12 ± 2	182 ± 78	27 ± 6	157 ± 25*	404 ± 64 (16%)	40 ± 5
E. 0.4% clofibrate	3	16 ± 5	278 ± 36#	19 ± 4	66 ± 14#	606 ± 56# (16%)	95 ± 10#
F. 0.4% clofibrate	0	18 ± 5	246 ± 18*	23 ± 4	127 ± 13*	507 ± 37* (20%)	81 ± 4*

Liver microsomes (0.5 mg protein) were incubated at 37 °C for 20 min with 50 μM [³H]-estradiol (E₂), 2 mM NADPH and 5 mM ascorbic acid. Each value is mean ± S.E. obtained with liver microsomes from 5 rats.

^aPercentage of E₂ metabolized is indicated in parenthesis.

^*Statistically different from control group receiving a 20 mg cholesterol pellet,

^#Statistically different from group receiving the same amount of E₂, P <0.05). (ANOVA followed by Bonferroni hoc post test)