Multidrug resistance-associated protein Abcc1, 3–6 expression in livers of C57BKS and db/db mice. A) Messenger RNA expression for Abcc1, 3, 4, 5 and 6. Total RNA was isolated from livers of adult db/db and C57BKS mice, and mRNA was quantified using branched DNA signal amplification assay. The data plotted as average Relative Light Unit (RLU) per 10 μg total RNA ± SEM. Asterisks (*) represent a statistically significant difference of expression between C57BKS and db/db mice of same gender (p≤0.05). Number sign (#) represents statistically significant expression difference between male and female db/db mice and male and female C57BKS mice. B) Abcc1, 3, 4, and 6 identification and quantification by western blot in crude membrane fractions from livers of C57BKS and db/db mice. Proteins (75 μg/lane) were separated on 4–20% acrylamide/bis PAGE, transblotted, incubated with primary and secondary antibodies and visualized by fluorescence. C) Quantification of western blots by using the Quantity One® software (Biorad, Hercules, CA). The average band intensity for C57BKS males was considered 100% and other groups were compared with that density. Asterisks (*) represent a statistically significant difference between average band intensity as compared to that of C57BKS males (p≤0.05). Abcc1 mRNA was unchanged but protein expression was upregulated in both male and female db/db mice. Abcc3 and 4 mRNA as well as protein expression was upregulated in both male and female db/db mice. Abcc5 and 6 mRNA expression was upregulated in db/db males, but remained unchanged in females.