PT  - JOURNAL ARTICLE
AU  - T Okano
AU  - H Maegawa
AU  - K Inui
AU  - R Hori
TI  - Interaction of ofloxacin with organic cation transport system in rat renal brush-border membranes.
DP  - 1990 Dec 01
TA  - Journal of Pharmacology and Experimental Therapeutics
PG  - 1033--1037
VI  - 255
IP  - 3
4099  - http://jpet.aspetjournals.org/content/255/3/1033.short
4100  - http://jpet.aspetjournals.org/content/255/3/1033.full
SO  - J Pharmacol Exp Ther1990 Dec 01; 255
AB  - Ofloxacin, a pyridonecarboxylic acid derivative, was examined for its effects on the transport of tetraethylammonium (cation), cephalexin and cephradine (zwitterions), p-aminohippurate (anion) and D-glucose in brush-border membrane vesicles isolated from rat renal cortex. The initial uptake of tetraethylammonium in the presence or absence of an outward H+ gradient was inhibited by ofloxacin in a dose-dependent manner, although the equilibrium value of tetraethylammonium uptake was not affected. This inhibition occurred in a competitive manner (Ki = 0.11 mM). Ofloxacin also inhibited the initial uptake of cephalexin and cephradine, which can be transported via the H+/organic cation antiport system in renal brush-border membranes. In contrast, ofloxacin had no effect on p-aminohippurate. These data suggest that ofloxacin interacts with the organic cation transport system in renal brush-border membranes, and this system may play an important role in the tubular secretion of ofloxacin.