Table 2.

Transporter protein expressions in human lung in COPD patients and healthy volunteers detected by immunohistochemistry

Tissue	P-gp		MATE1		OCTN1		OCTN2
	HV	COPD	HV	COPD	HV	COPD	HV	COPD
Bronchial epithelial cells	x	x	x	x	x	x	x	x
Bronchiolar epithelial cells	x	x	x	x	x	x	x	x
Alveolar epithelial cells (type II cells)	x	x	nd	nd	x	x	x	x
Alveolar macrophages	x	x	x	x	x	x	x	x
Lymphocytes in bronchia	nd	nd	x	x	nd	nd	nd	nd

^aInfiltrating in epithelial layer, HV: Tissue from healthy volunteers, COPD: Tissue from COPD patients, X: Expression detected, nd: Not detected