title: Liquid chromatographic-mass spectrometric determination of the metabolism and disposition of the anti-retroviral nucleoside analogs zidovudine and lamivudine in C57BL/6N and B6C3F1 mice.
abstract: Transmission of HIV from mother to infant can be effectively prevented by zidovudine (3'-azido-3'-deoxythymidine; AZT) alone or in combination with other anti-retroviral drugs; however, significant evidence for genotoxicity, including transplacental carcinogenicity in mice, has been reported for AZT. A method, based upon solid phase extraction (SPE) in the 96-well format, gradient liquid chromatography (LC), and electrospray mass spectrometry (MS), was developed and validated to measure serum concentrations in maternal C57BL/6N and fetal B6C3F1 mice of the nucleoside analogs AZT, lamivudine ((-)2',3'-dideoxy-3'-thiacytidine; 3TC), and several metabolites selected based on importance in detoxification and bioactivation reactions. After intravenous (i.v.) and oral dosing with either 400 mg/kg AZT or 200 mg/kg 3TC, pharmacokinetics were determined for AZT, AZT-5'-glucuronide, 3'-amino-3'-deoxythymidine (AMT), AZT-5'-phosphate, 3TC, and 3TC-5'-phosphate in serum of adult female mice. Pharmacokinetics were also determined in spleen for AZT-5'-phosphate and 3TC-5'-phosphate following i.v. dosing. In addition, a preliminary assessment was made of placental transfer of AZT and 3TC and the presence of metabolites in the fetal compartment. The method described provides a means to evaluate thoroughly metabolism and disposition of anti-retroviral nucleoside analogs in maternal and fetal mice for comprehensive studies of genotoxicity.
authors: Biochemical Toxicology Division, National Center for Toxicological Research, FDA, HFT-110, 3900 NCTR Road, Jefferson, AR 72079, USA.
authors: Lee D
authors: LD
authors: Williams
authors: Linda S
authors: LS
authors: Von Tungeln
authors: Frederick A
authors: FA
authors: Beland
authors: Daniel R
authors: DR
authors: Doerge
mesh_terms: D000818:Animals; D019540:Area Under Curve; D002853:Chromatography, Liquid / Q000379:methods*; D005260:Female; D005333:Fetus / Q000378:metabolism; D019259:Lamivudine / Q000097:blood / Q000493:pharmacokinetics*; D013058:Mass Spectrometry / Q000379:methods*; D051379:Mice; D008815:Mice, Inbred Strains; D015203:Reproducibility of Results; D018894:Reverse Transcriptase Inhibitors / Q000097:blood / Q000493:pharmacokinetics*; D015215:Zidovudine / Q000097:blood / Q000493:pharmacokinetics*
chemical_list: D018894:Reverse Transcriptase Inhibitors; D019259:Lamivudine; D015215:Zidovudine