Enzymatic assay for measurement of zidovudine triphosphate in peripheral blood mononuclear cells
| Autor: | Arnold Fridland, Craig M. McDonald, R V Srinivas, Patricia M. Flynn, Brian L. Robbins, John H. Rodman |
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| Rok vydání: | 1994 |
| Předmět: |
T-Lymphocytes
Radioimmunoassay Pharmacology Biology Antiviral Agents Peripheral blood mononuclear cell Monocytes Zidovudine Pharmacokinetics immune system diseases HIV Seropositivity medicine Humans Bioassay Pharmacology (medical) Cells Cultured Chromatography High Pressure Liquid virus diseases Half-life Liter Virology HIV Reverse Transcriptase Infectious Diseases HIV-1 Reverse Transcriptase Inhibitors Intracellular Dideoxynucleotides Half-Life Research Article medicine.drug |
| Zdroj: | Antimicrobial Agents and Chemotherapy. 38:115-121 |
| ISSN: | 1098-6596 0066-4804 |
| DOI: | 10.1128/aac.38.1.115 |
| Popis: | In this report, we describe a new method to measure intracellular zidovudine triphosphate (ZDV-TP) levels in peripheral blood mononuclear cells (PBMCs) from patients treated with ZDV by utilizing inhibition of human immunodeficiency virus type 1 reverse transcriptase activity by ZDV-TP. Intracellular levels of ZDV-TP were determined with our enzymatic assay in PBMCs isolated from the blood of healthy individuals incubated with different concentrations of labeled ZDV and were validated by high-performance liquid chromatography separation and liquid scintillation counting of the radioactive ZDV-TP. These methods gave virtually identical results over a range of ZDV-TP concentrations from 150 to 900 fmol. ZDV-TP recoveries were over 90%, and the limit of quantitation of ZDV-TP by this method was 20 to 50 fmol. To demonstrate the utility of the method, plasma ZDV and intracellular ZDV-TP concentrations were measured at serial time points over 6 h in 12 human immunodeficiency virus-infected volunteers following a single 100- or 500-mg oral dose of ZDV. Systemic oral clearance rates were similar to those in previous studies with adults but were highly variable (range, 0.86 to 2.75 liters/h/kg of body weight). The area under the plasma concentration versus time curve increased significantly (P < 0.0005) with the dose from a median value of 1.2 mg.h/liter at the lower dose to 4.2 mg.h/liter at the higher dose. Median intracellular ZDV-TP levels ranged from 5 to 57 and 42 to 92 fmol/10(6) cells in volunteers administered 100 and 500 mg of ZDV, respectively. Intracellular ZDV-TP levels rose to a plateau value by 2 h and remained consistent to 6 h. Although the higher dose and higher areas under the curve yielded consistently higher intracellular ZDV-TP levels, systemic pharmacokinetics explains only a modest proportion of the variability in cellular pharmacokinetic. The ZDV-TP bioassay should prove useful in further studies of ZDV metabolism in patient-derived PBMCs at the doses of ZDV currently administered. |
| Databáze: | OpenAIRE |
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