AGE- AND GENDER-RELATED DIFFERENCES IN XENOBIOTIC TRANSPORTER EXPRESSION - Drug Transporters: Molecular Characterization and Role in Drug Disposition - page 604

Enterocytes

Uptake Efflux

Oatp2b1

Mdr1a

Pept1

Mrp3
Ost

Cnt1

Mrp2

α

Cnt2

Bcrp

β
Abca1

Ost

Npc1L1

Abcg5

Octn1

Abcg8

Octn2

Ibat

Basolateral Basolateral

Apical Side

FIGURE 20.10. Cellular localization and transport direction of known transporters in intes-
tine. Uptake transporters in apical membrane are depicted in the enterocytes on the left. Efflux
transporters in the basolateral and apical membrane are shown in the enterocytes on the right.

INTESTINAL UPTAKE FROM LUMEN
−

Ref

2 0 5 0 5 3 0 5RLU

Cnt1 82 np

Cnt2 1100 np

Cnt3 48 np

Ibat/Asbt

84 np

np

Oatp2b1 150

Octn1 37 np

np

Pept1 1500

FIGURE 20.11. Ontogenic expression of apical uptake transporters Cnt1, 2, and 3, Ibat/Asbt,
Oatp2b1, Octn1, and Pept1 in enterocytes of male mice. Previous studies showed that there
is no gender difference in mRNA expression of these transporters in adult mouse duodenum.
Therefore, the total RNA from male C57BL/6 mouse duodenum at each age ( n 5) was

analyzed by the bDNA method. Data are presented as a ratio of mRNA expression at that age
to the highest observed in mouse duodenum. RLU (relative light unit) represents the highest
mRNA expression observed in mouse duodenum.

=