TABLE 1

Regioisomeric production and distribution of arachidonic acid epoxides in response to 48 h of treatment with TCDD, PB, and imidazole derivatives

Each regioisomer reflects the sum of the EETs + DHETs; 5,6-EET includes the 5,6-δ-lactone. The values in parentheses represent the regioisomers as percent ± S.E. of total EETs + DHETs (100%). TCDD, 1 nmol per egg; PB, 20 mg per egg; R76713, for 1, 3, and 9 mg per egg combined (all produced maximal induction and did not differ significantly); all others, 9 mg per egg. Total EETs + DHETs for the DMSO control were (n = 10) 0.048 ± 0.013 (nmol/mg microsomal protein/min).

Treatment	EETs + DHETs
Treatment		n	14,15	11,12	8,9	5,6	Total
				nmol/mg microsomal protein/min ± S.E.
TCDD	11	0.188 ± 0.019	0.175 ± 0.014	0.200 ± 0.020	0.283 ± 0.029	0.844 ± 0.067
		(22 ± 1.2)^c***	(21 ± 1.5)	(24 ± 1.2)^c***	(33 ± 1.8)^a^,^c***
PB	3	0.339 ± 0.014	0.162 ± 0.019	0.294 ± 0.001	0.067 ± 0.003	0.862 ± 0.027
		(40 ± 0.8)^a^,^b^,***	(19 ± 2)^a	(34 ± 0.9)^a^,^b**	(7 ± 0.6)^a^,^b***
ALB	4	0.161 ± 0.014	0.123 ± 0.014	0.168 ± 0.009	0.182 ± 0.011	0.635 ± 0.043
		(25 ± 0.9)^c**	(19 ± 1.1)^a	(27 ± 1.8)	(29 ± 0.3)^c***
BZY	4	0.193 ± 0.033	0.145 ± 0.024	0.142 ± 0.028	0.126 ± 0.017	0.605 ± 0.099
		(32 ± 0.7)^b*^,^c	(24 ± 0.6)	(23 ± 1.2)^c*	(21 ± 1.6)^b*^,^c
OP	4	0.191 ± 0.005	0.108 ± 0.009	0.140 ± 0.008	0.058 ± 0.007	0.497 ± 0.018
		(38 ± 1.6)^a^,^b***	(22 ± 1.3)^a	(28 ± 1.4)^a	(12 ± 1.3)^a^,^b***
R76713	13	0.178 ± 0.018	0.119 ± 0.008	0.190 ± 0.013	0.130 ± 0.013	0.616 ± 0.040
		(28.5 ± 1.6)^a^,^b^,^c	(19.5 ± 0.7)^a	(31 ± 1.2)^b**	(21 ± 1.7)^b*^,^c
TBZ	4	0.045 ± 0.008	0.024 ± 0.006	0.038 ± 0.008	0.021 ± 0.005	0.128 ± 0.013
		(35 ± 4.3)^b***	(20 ± 4.5)	(29 ± 4.4)	(16 ± 3.4)^b***

↵ a Significantly different from all other regioisomers for the same treatment (exceptions: ALB, 11,12 did not differ from 14,15; R76713, 11,12 did not differ from 5,6 nor 14,15 from 8,9). ^b Relative regioisomer production significantly different from TCDD. ^c Relative regioisomer production significantly different from PB. For ^b and ^c: * p < 0.05, ** p < 0.01, *** p < 0.001. For ^a: TCDD, p < 0.01; PB, p < 0.01, except p < 0.05 for 8,9 vs. 14,15; ALB, p < 0.05; OP, p < 0.001, except p < 0.01 for 11,12 vs. 8,9; R76713, p < 0.01, except p < 0.05 for 14,15. n = number of independent experiments. Abbreviations as in Fig. 2.