The organic cation transporters OCT1, 2, and 3 (SLC22A1-3) have been implicated in the elimination of biogenic amines such as histamine. Among them, OCT3 was identified as an uptake-2 transporter, responsible for clearance of histamine. Because increasing evidence suggests the involvement of histamine in cerebral ischemia, we investigated the effects of targeted disruption of organic cation tra...

Entecavir (ETV), a nucleoside analog with high efficacy against hepatitis B virus, is recommended as a first-line antiviral drug for the treatment of chronic hepatitis B. However, scant information is available on the use of ETV in pregnancy. To better understand the safety of ETV in pregnant women, we aimed to demonstrate whether ETV could permeate placental barrier and the underlying mechanis...

The driving forces mediating tetraethylammonium (TEA) transport were systematically assessed in Xenopus oocytes and MDCK cells expressing organic cation transporter (OCT) 2 cloned from rat kidney (rOCT2). In rOCT2 cRNA-injected oocytes, uptake of [14C]TEA was saturable, with an estimated Michaelis constant ( K m) of 393 μM, and was specifically inhibited by organic cations. Furthermore, TEA upt...

In human proximal tubules, organic cations are taken up from blood into cells by human organic cation transporter 2 [hOCT2/solute carrier (SLC) 22A2] and then eliminated into the lumen by apical H(+)/organic cation antiporters, human multidrug and toxin extrusion 1 (hMATE1/SLC47A1) and hMATE2-K (SLC47A2). To evaluate drug interactions of cationic drugs in the secretion process, epithelial cells...

Burckhardt, Gerhard, and Natascha A. Wolff. Structure of renal organic anion and cation transporters. Am J Physiol Renal Physiol 278: F853–F866, 2000.—Here we review the structural and functional properties of organic anion transporters (OAT1, OAT2, OAT3) and organic cation transporters (OCTN1, OCTN2, OCT1, OCT2, OCT3), some of which are involved in renal proximal tubular organic anion and cati...

A major function of xenobiotic and endobiotic transporters is to move a wide range of organic substances across cell membranes. Sertoli cells play an important role in protecting developing germ cells by forming a physiological barrier, limiting exposure to potentially toxic substrates, or conversely, facilitating uptake of xenobiotics within the testis. The aim of this study was to quantitativ...

The effect of several polyamines on the transport of organic cations [N1-[3H]methylnicotinamide (NMN), [3H]NMN and 3H-tetraethylammonium, ([3H]TEA)] in rabbit renal brush border (BBMV) and basolateral membrane vesicles (BLMV) was studied using a rapid filtration assay. Under pH-driven conditions in BBMV, [3H]NMN transport was cis inhibited approximately 30% by the naturally occurring polyamines...