Approaching complete inhibition of P-glycoprotein at the human blood–brain barrier: an (R)-[11C]verapamil PET study
نویسندگان
چکیده
As P-glycoprotein (Pgp) inhibition at the blood-brain barrier (BBB) after administration of a single dose of tariquidar is transient, we performed positron emission tomography (PET) scans with the Pgp substrate (R)-[(11)C]verapamil in five healthy volunteers during continuous intravenous tariquidar infusion. Total distribution volume (VT) of (R)-[(11)C]verapamil in whole-brain gray matter increased by 273 ± 78% relative to baseline scans without tariquidar, which was higher than previously reported VT increases. During tariquidar infusion whole-brain VT was comparable to VT in the pituitary gland, a region not protected by the BBB, which suggested that we were approaching complete Pgp inhibition at the human BBB.
منابع مشابه
A pilot study to assess the efficacy of tariquidar to inhibit P-glycoprotein at the human blood-brain barrier with (R)-11C-verapamil and PET.
UNLABELLED Tariquidar, a potent, nontoxic, third-generation P-glycoprotein (P-gp) inhibitor, is a possible reversal agent for central nervous system drug resistance. In animal studies, tariquidar has been shown to increase the delivery of P-gp substrates into the brain by severalfold. The aim of this study was to measure P-gp function at the human blood-brain barrier (BBB) after tariquidar admi...
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Background Positron emission tomography (PET) with the radiolabelled substrate of the multidrug efflux transporter Pglycoprotein (P-gp) (R)-[C]verapamil (VPM) can be used to assess P-gp function at the blood-brain barrier (BBB). We have shown in rats that performing VPM PET scans after half-maximum inhibition of P-gp with the third-generation P-gp inhibitor tariquidar (TQD) is more sensitive fo...
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UNLABELLED BACKGROUND This study investigated the influence of P-glycoprotein (P-gp) inhibitor tariquidar on the pharmacokinetics of P-gp substrate radiotracer (R)-[11C]verapamil in plasma and brain of rats and humans by means of positron emission tomography (PET). METHODS Data obtained from a preclinical and clinical study, in which paired (R)-[11C]verapamil PET scans were performed befor...
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