P-glycoprotein (P-gp), a major efflux pump in the blood-brain barrier (BBB) has a profound effect on entry of drugs, peptides and other substances into the central nervous system (CNS). The brain's permeability can be negatively influenced by modulation of the transport function of P-gp. Inflammatory mediators play a role in schizophrenia, and may be able to influence the integrity of the BBB, via P-gp modulation. We hypothesized that P-gp function in the BBB is changed in patients with schizophrenia. Positron-emission tomography was used to measure brain uptake of [(11)C]verapamil, which is normally extruded from the brain by P-gp. We found that patients with chronic schizophrenia under treatment with antipsychotic drugs compared with healthy controls showed a significant decrease in [(11)C]verapamil uptake in the temporal cortex, the basal ganglia, and the amygdala, and amygdalae, and a trend towards a significant decrease was seen throughout the brain. The decrease of [(11)C]verapamil uptake correlates with an increased activity of the P-gp pump. Increased P-gp activity may be a factor in drug resistance in schizophrenia, induced by the use of antipsychotic agents.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1016/j.pscychresns.2010.05.002 | DOI Listing |
Mol Imaging Biol
January 2025
Department of Nuclear Medicine and Molecular Imaging, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.
Purpose: This preclinical study explored the feasibility of assessing P-glycoprotein (P-gp) function in both brain and gastrointestinal (GI) tract of rats using positron emission tomography (PET) following oral administration of [F]MC225. Different oral administration protocols were evaluated, and radioactivity uptake was compared with uptake following intravenous administration.
Procedures: Twelve male Wistar rats were divided into four groups and subjected to intravenous or oral [F]MC225 administration protocols: G (intravenous route), G (oral administration without fasting), G (oral administration with fasting), and G (oral administration with fasting following administration of the P-gp inhibitor tariquidar).
Xi Bao Yu Fen Zi Mian Yi Xue Za Zhi
January 2025
National Key Laboratory of Bioreactors, School of Biological Engineering, East China University of Science and Technology, Shanghai 200237, China. *Corresponding author, E-mail:
Clin Pharmacokinet
January 2025
Clinical Pharmacology and Toxicology Service, Anesthesiology, Pharmacology and Intensive Care Department, Geneva University Hospitals, 4 Rue Gabrielle Perret-Gentil, 1205, Geneva, Switzerland.
Background And Objective: Fexofenadine is commonly used as a probe substrate to assess P-glycoprotein (Pgp) activity. While its use in healthy volunteers is well documented, data in older adult and polymorbid patients are lacking. Age- and disease-related physiological changes are expected to affect the pharmacokinetics of fexofenadine.
View Article and Find Full Text PDFVet Q
December 2025
Department of Physiology, Temerty Faculty of Medicine, University of Toronto, Toronto, Canada.
This review examines the role of the canine blood-brain barrier (BBB) in health and disease, focusing on the impact of the multidrug resistance (MDR) transporter P-glycoprotein (P-gp) encoded by the gene. The BBB is critical in maintaining central nervous system homeostasis and brain protection against xenobiotics and environmental drugs that may be circulating in the blood stream. We revise key anatomical, histological and functional aspects of the canine BBB and examine the role of the gene mutation in specific dog breeds that exhibit reduced P-gp activity and disrupted drug brain pharmacokinetics.
View Article and Find Full Text PDFSci Rep
January 2025
Pharmacy Department, University Clinical Hospital of Santiago de Compostela (SERGAS), 15706, Santiago de Compostela, Spain.
Aripiprazole (ARI) is an atypical antipsychotic which is a substrate of P-glycoprotein (P-gp), a transmembrane glycoprotein that plays a crucial role in eliminating potentially harmful compounds from the organism. ARI once-monthly (AOM) is a long-acting injectable form which improves treatment compliance. Genetic polymorphisms in ABCB1 may lead to changes in P-gp function, leading to individual differences in drug disposition.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!