Table 3

RNA expression levels of each transporter gene normalized to β-actin in lactating and nonlactating mammary epithelial cells and in liver, kidney, and placenta tissues

Transporter Gene	Transporter Gene to β-Actin Ratio
Transporter Gene	Lactating MEC	Nonlactating MEC	Liver Tissue	Kidney Tissue	Placenta Tissue
OCT1	3.50	0.451	4870	4.54	1.44
OCT2	BLD	BLD	BLD	10.3	BLD
OCT3	0.163	0.476	1.72	0.250	1.17
OCTN1	0.336	BLD	BLD	0.388	0.0517
OCTN2	0.622	2.51	0.185	6.26	2.64
OAT1	BLD	BLD	BLD	54.1	BLD
OAT2	BLD	BLD	39.3	2.76	BLD
OAT3	BLD	BLD	BLD	124	BLD
OAT4	BLD	BLD	0.174	48.6	17.7
OATPA	0.0833	0.0525	BLD	0.00488	0.0111
OATPB	0.945	0.641	16.6	1.206	5.04
OATPC	BLD	BLD	18.9	BLD	BLD
OATPD	3.64	6.63	0.787	2.04	1.07
OATPE	0.137	0.371	0.062	0.121	0.179
MDR1	0.0258	1.33	0.157	2.81	6.30
MRP1	0.355	0.917	0.429	0.427	1.09
MRP2	0.0506	0.0586	0.261	0.214	0.0733
MRP3	BLD	BLD	BLQ	BLQ	BLQ
MRP4	BLD	BLD	BLD	BLQ	BLQ
MRP5	0.0670	0.0388	0.0345	0.0722	0.244
PEPT1	0.0540	0.159	3.42	5.22	0.876
PEPT2	1.59	BLD	BLD	E	E
CNT1	0.176	BLD	ACR	BLQ	BLQ
CNT2	BLD	BLD	BLD	E	E
CNT3	0.334	0.0480	BLD	BLD	BLD
ENT1	0.490	0.658	2.74	0.707	0.462
ENT2	BLD	BLD	BLD	E	E
ENT3	0.0782	BLD	0.127	0.101	41.0
NCBT1	0.961	0.440	6.24	1.14	0.476
NCBT2	BLD	BLD	E	ACR	BLD

BLD, below level of detection (comparable to negative control); BLQ, below level of quantification, but above level of negative control; E, expression, but unable to quantitate due to interference in melting curve analysis; ACR, above calibration curve range.