RT Journal Article SR Electronic T1 Transport of Angiotensin-Converting Enzyme Inhibitors by H+/Peptide Transporters Revisited JF Journal of Pharmacology and Experimental Therapeutics JO J Pharmacol Exp Ther FD American Society for Pharmacology and Experimental Therapeutics SP 432 OP 441 DO 10.1124/jpet.108.143339 VO 327 IS 2 A1 Ilka Knütter A1 Claudia Wollesky A1 Gabor Kottra A1 Martin G. Hahn A1 Wiebke Fischer A1 Katja Zebisch A1 Reinhard H. H. Neubert A1 Hannelore Daniel A1 Matthias Brandsch YR 2008 UL http://jpet.aspetjournals.org/content/327/2/432.abstract AB Angiotensin-converting enzyme (ACE) inhibitors are often regarded as substrates for the H+/peptide transporters (PEPT)1 and PEPT2. Even though the conclusions drawn from published data are quite inconsistent, in most review articles PEPT1 is claimed to mediate the intestinal absorption of ACE inhibitors and thus to determine their oral availability. We systematically investigated the interaction of a series of ACE inhibitors with PEPT1 and PEPT2. First, we studied the effect of 14 ACE inhibitors including new drugs on the uptake of the dipeptide [14C]glycylsarcosine into human intestinal Caco-2 cells constitutively expressing PEPT1 and rat renal SKPT cells expressing PEPT2. In a second approach, the interaction of ACE inhibitors with heterologously expressed human PEPT1 and PEPT2 was determined. In both assay systems, zofenopril and fosinopril were found to have very high affinity for binding to peptide transporters. Medium to low affinity for transporter interaction was found for benazepril, quinapril, trandolapril, spirapril, cilazapril, ramipril, moexipril, quinaprilat, and perindopril. For enalapril, lisinopril, and captopril, very weak affinity or lack of interaction was found. Transport currents of PEPT1 and PEPT2 expressed in Xenopus laevis oocytes were recorded by the two-electrode voltage-clamp technique. Statistically significant, but very low currents were only observed for lisinopril, enalapril, quinapril, and benazepril at PEPT1 and for spirapril at PEPT2. For the other ACE inhibitors, electrogenic transport activity was extremely low or not measurable at all. The present results suggest that peptide transporters do not control intestinal absorption and renal reabsorption of ACE inhibitors. The American Society for Pharmacology and Experimental Therapeutics