Transport of valganciclovir, a ganciclovir prodrug, via peptide transporters PEPT1 and PEPT2.

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Sugawara M, Huang W, Fei YJ, Leibach FH, Ganapathy V, Ganapathy ME

Transport of valganciclovir, a ganciclovir prodrug, via peptide transporters PEPT1 and PEPT2.

J Pharm Sci. 2000 Jun;89(6):781-9.

PubMed ID

10824137 [ View in PubMed

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Abstract

In clinical trials, valganciclovir, the valyl ester of ganciclovir, has been shown to enhance the bioavailability of ganciclovir when taken orally by patients with cytomegalovirus infection. We investigated the role of the intestinal peptide transporter PEPT1 in this process by comparing the interaction of ganciclovir and valganciclovir with the transporter in different experimental systems. We also studied the interaction of these two compounds with the renal peptide transporter PEPT2. In cell culture model systems using Caco-2 cells for PEPT1 and SKPT cells for PEPT2, valganciclovir inhibited glycylsarcosine transport mediated by PEPT1 and PEPT2 with K(i) values (inhibition constant) of 1.68+/-0.30 and 0.043+/- 0.005 mM, respectively. The inhibition by valganciclovir was competitive in both cases. Ganciclovir did not interact with either transporter. Similar studies done with cloned PEPT1 and PEPT2 in heterologous expression systems yielded comparable results. The transport of valganciclovir via PEPT1 was investigated directly in PEPT1-expressing Xenopus laevis oocytes with an electrophysiological approach. Valganciclovir, but not ganciclovir, induced inward currents in PEPT1-expressing oocytes. These results demonstrate that the increased bioavailability of valganciclovir is related to its recognition as a substrate by the intestinal peptide transporter PEPT1. This prodrug is also recognized by the renal peptide transporter PEPT2 with high affinity.

DrugBank Data that Cites this Article

Drug Transporters

Drug	Transporter	Kind	Organism	Pharmacological Action	Actions
Valganciclovir	Solute carrier family 15 member 1	Protein	Humans	Unknown	Not Available	Details
Valganciclovir	Solute carrier family 15 member 2	Protein	Humans	Unknown	Not Available	Details