Table 1.

P-gp and BCRP expression in fetal tissues and temporal changes over gestation

	Human		Mice		Rat
	P-gp	BCRP	P-gp	Bcrp	P-gp	Bcrp
Brain	↑	↔	↑	+	↑	↓
Liver	↑	+	+	↓	↔	↓
Kidney	+	+	+	+	+	+
Intestine	↔	↔	↑	n/a	↔	+

↑ indicates increases over gestation. ↓ indicates decreases over gestation. ↔ means consistent expression over gestation; + denotes positive evidence of expression but unknown temporal changes or conflicting data. “n/a” means data not available. [97–131]