Epithelial Organic Cation Transporters Ensure pH-Dependent Drug Absorption in the Airway

Abstract

ϩ uptake, suggesting that all these molecules are carried by the same transport mechanism. These findings demonstrate the existence and functional role of a pHdependent organic cation uptake machinery, namely OCTN1 and OCTN2, in human airway epithelia. We suggest that epithelial OCTN1/2 are involved in the delivery of inhaled cationic bronchodilators to the airway tissue.

Long-chain Acyl-CoA Dehydrogenase Deficiency as a Cause of Pulmonary Surfactant Dysfunction

“…For instance, conditions that deplete carnitine can severely limit FAO, which is carnitine-dependent. Lung cannot synthesize carnitine and must therefore transport it via the transporter protein OCTN2 that is expressed in the alveolar epithelium (53). Besides carnitine, OCTN2 transports many cationic drugs, including ipratropium, which is an inhaled therapeutic for COPD and asthma (54).…”

Organic cation transporter function in different in vitro models of human lung epithelium

“…Membrane transporters have been confirmed to be present throughout the different areas of lung mucosa (Gumbleton et al, 2011), however, only a limited number of activity studies have been carried out in human pulmonary epithelial cells thus far. To worsen the situation, most studies have utilised dissimilar in vitro models (Horvath et al, 2007;Macdonald et al, 2013;Mukherjee et al, 2012;. There is thus, an urgent demand for physiologically relevant and well-characterised in vitro models of human lung epithelium for studies of pulmonary solute transport, e.g.…”

Inhaled chemotherapy in lung cancer: future concept of nanomedicine

“…OCT N1 is expressed in the tracheal epithelium and alveolar macrophages, whereas OCT N2 is expressed in the alveolar epithelium and airway epithelium. [215][216][217][218] Published data for animal and in vitro cell lines implicate upregulation or downregulation of OCT transporters upon induced inflammation or drug interactions related to asthma and/or COPD. Nevertheless, these are not clearly associated with a human model [217][218][219][220] (Figure 2).…”