% IMPORTANT: The following is UTF-8 encoded. This means that in the presence % of non-ASCII characters, it will not work with BibTeX 0.99 or older. % Instead, you should use an up-to-date BibTeX implementation like “bibtex8” or % “biber”. @ARTICLE{Benzel:176948, author = {J. Benzel$^*$ and G. Bajraktari-Sylejmani and P. Uhl and A. Davis and S. Nair and S. M. Pfister$^*$ and W. E. Haefeli and J. Weiss and J. Burhenne and K. W. Pajtler$^*$ and M. Sauter}, title = {{I}nvestigating the {C}entral {N}ervous {S}ystem {D}isposition of {A}ctinomycin {D}: {I}mplementation and {E}valuation of {C}erebral {M}icrodialysis and {B}rain {T}issue {M}easurements {S}upported by {UPLC}-{MS}/{MS} {Q}uantification.}, journal = {Pharmaceutics}, volume = {13}, number = {9}, issn = {1999-4923}, address = {Basel}, publisher = {MDPI}, reportid = {DKFZ-2021-02188}, pages = {1498}, year = {2021}, note = {#EA:B062#}, abstract = {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.}, keywords = {UPLC-MS/MS (Other) / actinomycin D (Other) / central nervous system (Other) / cerebral microdialysis (Other) / micro-sampling (Other)}, cin = {B062 / HD01}, ddc = {610}, cid = {I:(DE-He78)B062-20160331 / I:(DE-He78)HD01-20160331}, pnm = {312 - Funktionelle und strukturelle Genomforschung (POF4-312)}, pid = {G:(DE-HGF)POF4-312}, typ = {PUB:(DE-HGF)16}, pubmed = {pmid:34575574}, pmc = {pmc:PMC8466300}, doi = {10.3390/pharmaceutics13091498}, url = {https://inrepo02.dkfz.de/record/176948}, }