Research PapersRenal Cellular Transport, Metabolism, and Cytotoxicity of S-(6-Purinyl)glutathione, a Prodrug of 6-Mercaptopurine, and Analogues
Section snippets
Materials
6-PG and DCVC were synthesized as previously described 11, 15. Purity was > 95%, as assessed by HPLC, FAB-MS, and 1H NMR. 6-MP, 6-ThXan, 6-ThGua, acivicin, AOAA, allopurinol, KMB, and collagenase (type I) were purchased from the Sigma Chemical Co. (St. Louis, MO). All other chemicals were of the highest purity available and were obtained from commercial sources. Solutions of acivicin, AOAA, allopurinol, KMB, or 6-PG were prepared in Krebs–Henseleit buffer or saline. Solutions of 6-MP, 6-ThXan,
Accumulation of 6-PG and 6-MP
Uptake and net intracellular accumulation of 0.1 to 1 mM 6-PG over a 60-min time course was measured in suspensions of renal cortical cells preincubated with either buffer (Fig. 2A), 0.25 mM acivicin to inhibit GGT (Fig. 2B), or 10 mM KMB to stimulate the β-lyase (Fig. 2C). Under control conditions with buffer, 6-PG accumulated to a maximum intracellular level of 14.2 nmol/106 cells at 15 min with 1 mM 6-PG and decreased thereafter to reach a level of 8.02 nmol/106 cells at 60 min. Net
Discussion
6-PG and 6-PC are metabolized both in vivo and in vitro to 6-MP in the kidneys of rats, and administration of 6-PG or 6-PC leads to the selective renal accumulation of 6-MP 9, 10, 11. These data suggested that 6-PG and 6-PC can function as prodrugs of the antitumor agent 6-MP. Additional studies showed that 6-CP, which also has antitumor activity, is metabolized in vivo to 6-PG and 6-MP, suggesting that metabolism of 6-CP through the GSH conjugation and β-lyase pathways may play a role in the
Acknowledgements
This work was supported by National Institute of Diabetes and Digestive and Kidney Diseases Grants R01-DK40725 (L. H. L.) and R01-DK44295 (A. A. E.). L. H. L. is a recipient of a Research Career Development Award (Grant K04-DK02090) from the National Institute of Diabetes and Digestive and Kidney Diseases. The authors also thank Mr. David A. Putt for his technical assistance.
References (33)
- et al.
Prodrugs and site-specific chemical delivery systems
Annu Rep Med Chem
(1987) - et al.
The inhibition of γ-glutamyl transpeptidase and glutathione metabolism of isolated rat kidney cells by l-(αS,5S)-α-amino-3-chloro-4,5-dihydro-5-isoxazoleacetic acid (AT-125; NSC-163501)
Biochem Biophys Res Commun
(1980) - et al.
Cytotoxicity of S-(1,2-dichlorovinyl)glutathione and S-(1,2-dichlorovinyl)-l-cysteine in isolated rat kidney cells
J Biol Chem
(1986) - et al.
Use of isolated kidney cells for study of drug metabolism
Biochem Pharmacol
(1979) - et al.
Isolation of two distinct populations of cells from rat kidney cortex and their use in the study of chemical-induced toxicity
Anal Biochem
(1989) - et al.
The mechanism of dietary alterations in rat hepatic xanthine oxidase levels
J Biol Chem
(1966) - et al.
A sensitive fluorometric assay for measuring xanthine dehydrogenase and oxidase in tissues
Free Radic Biol Med
(1989) - et al.
Renal glutathione transportCharacteristics of the sodium-dependent system in the basal-lateral membrane
J Biol Chem
(1984) - et al.
Mechanism of S-(1,2-dichlorovinyl)glutathione-induced nephrotoxicity
Biochem Pharmacol
(1986) - et al.
Biosynthesis and biotransformation of glutathione S-conjugates to toxic metabolites
CRC Crit Rev Toxicol
(1988)
Uptake of the glutathione conjugate S-(1,2-dichlorovinyl)glutathione by renal basal-lateral membrane vesicles and isolated kidney cells
Mol Pharmacol
Uptake of nephrotoxic S-conjugates by isolated rat renal proximal tubular cells
J Pharmacol Exp Ther
Mechanism of transport of toxic cysteine conjugates in rat kidney cortex membrane vesicles
Mol Pharmacol
Local immunosuppression with reduced systemic toxicity in a canine renal allograft model
Transplant Proc
An implantable pump for intrarenal infusion of immunosuppressants in a canine autotransplant model
Pharm Res
The pharmacokinetic advantage of local 6-mercaptopurine infusion in a canine renal transplant model
Transplant Proc
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