Characterization of the carrier‐mediated transport of ketoprofen, a nonsteroidal anti‐inflammatory drug, in rabbit corneal epithelium cells. (7th September 2012)

• Record Type: Journal Article
• Authors: Fujii, Shinobu; Hayashi, Hideki; Itoh, Kunihiko; Yamada, Shizuo; Deguchi, Yoshiharu; Kawazu, Kouichi
• Is Part Of: Journal of pharmacy and pharmacology. Volume 65:Number 2(2013:Feb.)
• Page Start: 171
• Page End: 180
• Publication Date: 2012-09-07
• Subjects: Pharmacy -- Periodicals; Pharmacology -- Periodicals; 615.1
• DOI: 10.1111/j.2042-7158.2012.01583.x
• Languages: English
• ISSNs: 0022-3573

Abstract

<abstract abstract-type="main"> <title>Abstract</title> <sec id="jphp1583-sec-0001" sec-type="section"> <title>Objectives</title> <p>Using rabbit corneal epithelial cells (RCECs), the transport of a nonsteroidal anti‐inflammatory drug (NSAID) [<sup>3</sup>H]ketoprofen across the cornea was investigated with the aim of revealing the mechanism of uptake.</p> </sec> <sec id="jphp1583-sec-0002" sec-type="section"> <title>Methods</title> <p>[<sup>3</sup>H]Ketoprofen transport was evaluated by measuring the permeability across the RCECs layers.</p> </sec> <sec id="jphp1583-sec-0003" sec-type="section"> <title>Key findings</title> <p>[<sup>3</sup>H]Ketoprofen uptake was time, temperature and pH dependent. Maximal uptake occurred from a solution with a pH of 5.25. Uptake was also reduced by metabolic inhibitors (sodium azide and dinitrophenol (DNP)) and proton‐linked monocarboxylate transporter (MCT) inhibitors (carbonyl cyanide <italic>p</italic>‐trifluoromethoxyphenylhydrazone (FCCP) and α‐cyano‐4‐hydroxycinnamic acid (CHC)). [<sup>3</sup>H]Ketoprofen uptake was significantly inhibited by various monocarboxylates and other NSAIDs and by MCT and/or organic anion transporter (OAT) inhibitors probenecid and <italic>p</italic>‐aminohippurate, but was unaffected by organic anion‐transporting polypeptide (OATP) inhibitors bromosulfophthalein and taurocholate. The specific uptake of [<sup>3</sup>H]ketoprofen was saturable. Eadie–Hofstee plots indicated the involvement of high‐ and low‐affinity components. The <italic>K<sub>m</sub></italic> and <italic>V<sub>max</sub></italic> values for the high‐ and low‐affinity components of [<sup>3</sup>H]ketoprofen uptake were 0.56 and 24 m<sc>m</sc>, and 0.37 and 61 nmol/min/mg of protein, respectively. Benzoic acid, a substrate and inhibitor of MCTs, selectively inhibited low‐affinity [<sup>3</sup>H]ketoprofen uptake. Conversely, indometacin inhibited high‐affinity [<sup>3</sup>H]ketoprofen uptake.</p> </sec> <sec id="jphp1583-sec-0004" sec-type="section"> <title>Conclusion</title> <p>The results of this study suggest that the monocarboxylate transport system partly accounts for the low‐affinity component of [<sup>3</sup>H]ketoprofen uptake, and that the carrier‐mediated transport systems such as the OAT family, shared by NSAIDs account for the high‐affinity component.</p> </sec> </abstract>