Table 1

Prevention of the IL-2-mediated decrease in CYP proteins and erythromycin demethylation by retinoic acid, n-butyric acid, and DMSO

Treatment	Immunoreactive CYP Protein		Erythromycin Demethylation
Treatment	1A1	1A2	Erythromycin Demethylation	2B1/2	2C11	2D1	3A
	% of control		nmol/min/mg protein
Control	100 ± 9	100 ± 17	100 ± 15	100 ± 18	100 ± 5	100 ± 8	0.17 ± 0.03
IL-2	63 ± 18^1-a	75 ± 8	62 ± 9^1-a	64 ± 12^1-a	61 ± 10^1-a	62 ± 9^1-a	0.10 ± 0.02^1-a
Retinoic acid	102 ± 45	133 ± 33	75 ± 12	76 ± 24	122 ± 21	77 ± 12	0.14 ± 0.03
Retinoic acid + IL-2	109 ± 36	141 ± 29	87 ± 6	74 ± 23	105 ± 9	85 ± 8	0.16 ± 0.03
n-Butyric acid	91 ± 17	101 ± 16	88 ± 7	71 ± 8	89 ± 6	78 ± 16	0.16 ± 0.02
n-Butyric acid + IL-2	99 ± 8	130 ± 42	81 ± 6	82 ± 9	94 ± 10	86 ± 13	0.14 ± 0.02
DMSO	108 ± 34	96 ± 40	90 ± 9	88 ± 10	78 ± 9	79 ± 15	0.13 ± 0.02
DMSO + IL-2	92 ± 27	83 ± 39	90 ± 18	99 ± 8	95 ± 12	84 ± 10	0.15 ± 0.03

After cell attachment, hepatocytes were cultured for 24 h with or without IL-2 (350 U/ml), retinoic acid (10 μM), n-butyric acid (3 mM), and DMSO (2%). Microsomal proteins (10 μg) were separated by SDS-10% PAGE, transferred to nitrocellulose sheets, revealed by antibodies, quantified by laser densitometry, and expressed as percentage of that in control cells. Erythromycin demethylation was measured in cell homogenates. Results are mean ± S.E.M. for four or five cultures.

↵1-a Different from the corresponding incubation without IL-2 (P < .05).