5-LO and COX-2 protein levels in the liver tissue of newborn pups. Tissues were homogenized and proteins were separated by SDS-PAGE, transferred to nitrocellulose membranes, and probed with 5-LO (A) or COX-2 (B) antibodies. Bands were quantitated by densitometry, and data were normalized to β-actin. Results are reported as mean ± SEM and data were assessed by two-way ANOVA with modified t test posthoc for individual differences, n = 6, p < 0.05. And effect of day, an effect of exposure, and an interaction were detected on 5-LO levels, and an effect of exposure was detected on COX-2 levels. *Indicates different from same day RA.