title: Carrier-mediated transport of cephalexin via the dipeptide transport system in rat renal brush-border membrane vesicles.
abstract: Carrier-mediated transport of aminocephalosporin antibiotics by renal brush-border membrane vesicles has been studied in relation to the transport systems for dipeptides and amino acids. Dipeptides such as L-carnosine (beta-alanyl-L-histidine) and L-phenylalanylglycine competitively inhibited the uptake of cephalexin, but amino acids did not. Cephalexin uptake was stimulated by the countertransport effect of L-carnosine in the normal and papain-treated vesicles, and by the effect of L-phenylalanylglycine only in the papain-treated vesicles. In the papain-treated vesicles, the hydrolysis of dipeptides was markedly decreased, and the specific activity for cephalexin transport was increased approx. 2-fold because of the partial removal of membrane proteins. These results suggest that carrier-mediated transport of cephalexin can be transported by the system for dipeptides in renal brush-border membranes.
mesh_terms: D000596:Amino Acids / Q000494:pharmacology; D000818:Animals; D001693:Biological Transport, Active; D002336:Carnosine / Q000494:pharmacology; D002506:Cephalexin / Q000378:metabolism*; D004151:Dipeptides / Q000378:metabolism* / Q000494:pharmacology; D007668:Kidney / Q000648:ultrastructure*; D007700:Kinetics; D008297:Male; D008871:Microvilli / Q000378:metabolism; D010206:Papain / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains
chemical_list: D000596:Amino Acids; D004151:Dipeptides; C040500:phenylalanylglycine; D002336:Carnosine; D010206:Papain; D002506:Cephalexin