TY - JOUR AU - Benzel, Julia AU - Bajraktari-Sylejmani, Gzona AU - Uhl, Philipp AU - Davis, Abigail AU - Nair, Sreenath AU - Pfister, Stefan M AU - Haefeli, Walter E AU - Weiss, Johanna AU - Burhenne, Jürgen AU - Pajtler, Kristian W AU - Sauter, Max TI - Investigating the Central Nervous System Disposition of Actinomycin D: Implementation and Evaluation of Cerebral Microdialysis and Brain Tissue Measurements Supported by UPLC-MS/MS Quantification. JO - Pharmaceutics VL - 13 IS - 9 SN - 1999-4923 CY - Basel PB - MDPI M1 - DKFZ-2021-02188 SP - 1498 PY - 2021 N1 - #EA:B062# AB - Actinomycin D is a potent cytotoxic drug against pediatric (and other) tumors that is thought to barely cross the blood-brain barrier. To evaluate its potential applicability for the treatment of patients with central nervous system (CNS) tumors, we established a cerebral microdialysis model in freely moving mice and investigated its CNS disposition by quantifying actinomycin D in cerebral microdialysate, brain tissue homogenate, and plasma. For this purpose, we developed and validated an ultraperformance liquid chromatography-tandem mass spectrometry assay suitable for ultra-sensitive quantification of actinomycin D in the pertinent biological matrices in micro-samples of only 20 µL, with a lower limit of quantification of 0.05 ng/mL. In parallel, we confirmed actinomycin D as a substrate of P-glycoprotein (P-gp) in in vitro experiments. Two hours after intravenous administration of 0.5 mg/kg, actinomycin D reached total brain tissue concentrations of 4.1 ± 0.7 ng/g corresponding to a brain-to-plasma ratio of 0.18 ± 0.03, while it was not detectable in intracerebral microdialysate. This tissue concentration exceeds the concentrations of actinomycin D that have been shown to be effective in in vitro experiments. Elimination of the drug from brain tissue was substantially slower than from plasma, as shown in a brain-to-plasma ratio of approximately 0.53 after 22 h. Because actinomycin D reached potentially effective concentrations in brain tissue in our experiments, the drug should be further investigated as a therapeutic agent in potentially susceptible CNS malignancies, such as ependymoma. KW - UPLC-MS/MS (Other) KW - actinomycin D (Other) KW - central nervous system (Other) KW - cerebral microdialysis (Other) KW - micro-sampling (Other) LB - PUB:(DE-HGF)16 C6 - pmid:34575574 C2 - pmc:PMC8466300 DO - DOI:10.3390/pharmaceutics13091498 UR - https://inrepo02.dkfz.de/record/176948 ER -