Quantitative determination of D₄-cystine in mice using LC-MS/MS and its application to the assessment of pharmacokinetics and bioavailability.

ABSTRACT: Cystine is the primary source material for the synthesis of glutathione. However, the pharmacokinetics and tissue distribution of cystine are largely unknown. A surrogate analyte D₄-cystine was employed to generate calibration curves for the determination of levels of D₄-cystine and endogenous cystine in mice by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Validation assessments proved the sensitivity, specificity and reproducibility of the method with a lower limit of quantification (LLOQ) of 5 ng/mL over 5-5000 ng/mL in plasma. The pharmacokinetics of D₄-cystine were evaluated after administering injections and oral solutions, both of which minimally impacted endogenous cystine levels. The absolute bioavailability of cystine was 18.6%, 15.1%

SUBMITTER: Li S 

PROVIDER: S-EPMC8572678 | biostudies-literature | 2021 Oct

REPOSITORIES: biostudies-literature