학술논문

Selamectin is a potent substrate and inhibitor of human and canine P-glycoprotein.
Document Type
Article
Source
Journal of Veterinary Pharmacology & Therapeutics. Jun2005, Vol. 28 Issue 3, p257-265. 9p.
Subject
*ANTIPARASITIC agents
*VETERINARY drugs
*GLYCOPROTEINS
*EPITHELIAL cells
*LYMPHOCYTES
*VETERINARY pharmacology
Language
ISSN
0140-7783
Abstract
Griffin, J., Fletcher, N., Clemence, R., Blanchflower, S., Brayden, D. J. Selamectin is a potent substrate and inhibitor of human and canine P-glycoprotein. J. vet. Pharmacol. Therap. 28, 257–265. The transport of the antiparasitic agents, ivermectin, selamectin and moxidectin was studied in human intestinal epithelial cell monolayers (Caco-2) and canine peripheral blood lymphocytes (PBL). Both models expressed the mdr1-coded 170 kDa ATP-binding cassette (ABC) transporter P-glycoprotein (P-gp). Fluxes of the P-gp substrate rhodamine-123 (Rh-123) across Caco-2 monolayers showed that ivermectin and selamectin acted as potent P-gp inhibitors with IC50 values of 0.1 μ m. In contrast, moxidectin was a weaker P-gp inhibitor with an IC50 of 10 μ m. The transport of radiolabelled ivermectin, selamectin and moxidectin through Caco-2 monolayers showed that ivermectin, selamectin and moxidectin were P-gp substrates with secretory/absorptive ratios of 7.5, 4.7 and 2.6 respectively. Secretory transport of [3H]-ivermectin and [3H]-selamectin was blocked by the P-gp inhibitor, verapamil. Ivermectin and selamectin inhibited the efflux of Rh-123 from PBL and the concentration of inhibition was similar to that of verapamil. In contrast, moxidectin did not have a significant effect on Rh-123 efflux from PBL. The data suggest that ivermectin and selamectin are potent P-gp substrates, while moxidectin is a weak one. [ABSTRACT FROM AUTHOR]