98%
921
2 minutes
20
The blood-brain barrier (BBB) controls brain homeostasis; it is formed by vascular endothelial cells that are physically connected by tight junctions (TJs). The BBB expresses efflux transporters such as P-glycoprotein (P-gp) and breast cancer resistance protein (BCRP), which limit the passage of substrate molecules from blood circulation to the brain. Focused ultrasound (FUS) with microbubbles can create a local and reversible detachment of the TJs. However, very little is known about the effect of FUS on the expression of efflux transporters. We investigated the in vivo effects of moderate acoustic pressures on both P-gp and BCRP expression for up to two weeks after sonication. Magnetic resonance-guided FUS was applied in the striatum of 12 rats. P-gp and BCRP expression were determined by immunohistochemistry at 1, 3, 7, and 14 days postFUS. Our results indicate that FUS-induced BBB opening is capable of (i) decreasing P-gp expression up to 3 days after sonication in both the treated and in the contralateral brain regions and is capable of (ii) overexpressing BCRP up to 7 days after FUS in the sonicated regions only. Our findings may help improve FUS-aided drug delivery strategies by considering both the mechanical effect on the TJs and the regulation of P-gp and BCRP.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC9779754 | PMC |
http://dx.doi.org/10.3390/ijms232415488 | DOI Listing |
Background Fentanyl is a potent synthetic opioid widely used for pain management and anesthesia, but the high prevalence of its misuse and its key contribution to overdose fatalities in the United States have made it a major drug of concern. Although fentanyl's onset, duration, and toxicity depend on its pharmacokinetics and specific tissue distribution, most studies have focused primarily on plasma concentrations, leaving its distribution in critical tissues largely unexplored (this knowledge gap limits our understanding of fentanyl's clinical effects, tissue accumulation, and the factors influencing its efficacy and safety). Here, we report the radiosynthesis of [ C]fentanyl for PET imaging and present a preliminary whole-body pharmacokinetic study in rodents.
View Article and Find Full Text PDFDrug Des Devel Ther
September 2025
Hebei General Hospital, Hebei Key Laboratory of Clinical Pharmacy, Shijiazhuang, 050051, People's Republic of China.
Background: Apixaban and rivaroxaban are oral direct factor Xa inhibitors, primarily eliminated through CYP3A4-mediated metabolism and direct intestinal excretion. Previous studies suggest that palbociclib, a CDK4/6 inhibitor, may increase the systemic exposure of these anticoagulants; however, the specific pharmacokinetic mechanisms remain unclear. This study aims to evaluate the effects of palbociclib on the pharmacokinetics of apixaban and rivaroxaban using a rat model to optimize combined drug regimens.
View Article and Find Full Text PDFPharmaceutics
August 2025
Drug Clinical Trial Center, Peking University Third Hospital, Beijing 100191, China.
Physiologically based pharmacokinetic (PBPK) modeling is a powerful tool for predicting pharmacokinetics (PK) to support drug development and precision medicine. However, it has not been established for non-renal clearance pathways in patients with end-stage renal disease (ESRD), a population that bears heavy medication burden and is thereby at high risk for drug-drug-disease interactions (DDDIs). Furthermore, the pronounced inter-individual variability in PK observed in ESRD patients highlights the urgent need for individualized PBPK models.
View Article and Find Full Text PDFJ Clin Pharmacol
August 2025
Office of Clinical Pharmacology, Office of Translational Sciences, Center for Drug Evaluation and Research, US Food and Drug Administration, Silver Spring, MD, USA.
Physiologically based pharmacokinetic (PBPK) models have gained interest as a tool for predicting drug transfer to human milk and assessing the exposure levels in infants. Our group previously developed an integrated lactation PBPK model framework to understand the transfer of drugs into milk and the resulting exposure in infants. As a part of the framework, the current paper focuses on performance of lactation PBPK models to predict maternal plasma and milk concentrations for drugs that are not substrates of P-glycoprotein (P-gp) or breast cancer resistance protein (BCRP) transporters-atenolol, escitalopram, and alprazolam.
View Article and Find Full Text PDFBr J Clin Pharmacol
August 2025
Pfizer, Inc., San Diego, CA, USA.
Aims: To evaluate the effects of vepdegestrant, a PROteolysis TArgeting Chimera (PROTAC) oestrogen receptor degrader, on the pharmacokinetics of dabigatran (a P-glycoprotein [P-gp] substrate) and rosuvastatin (a breast cancer resistance protein [BCRP] substrate).
Methods: In two phase 1, open-label, two-period, fixed-sequence studies, healthy adult participants received a single oral dose of dabigatran etexilate 75 mg or rosuvastatin 10 mg alone and with a single dose of vepdegestrant 200 mg. Serial plasma samples were collected after dosing, and pharmacokinetic parameters for dabigatran and rosuvastatin were estimated by standard noncompartmental analysis.