[11C]glyburide PET imaging for quantitative determination of the importance of Organic Anion-Transporting Polypeptide transporter function in the human liver and whole-body - 15/11/22
Abstract |
Organic Anion-Transporting Polypeptides (OATPs) are known to control the liver uptake of many drugs. Non-hepatic expression of OATPs has been reported although functional importance for whole-body pharmacokinetics (WBPK) remains unknown. Glyburide is a well described substrate of several hepatic and non-hepatic OATPs. Dynamic whole-body positron emission tomography (DWB-PET) with [11C]glyburide was performed in humans for determination of the importance of OATPs for liver uptake and WBPK. Seven healthy male subjects (24.7 ± 3.2 years) underwent [11C]glyburide PET scan with concomitant blood sampling. All subjects underwent baseline [11C]glyburide PET scan. Five subjects underwent a subsequent [11C]glyburide PET scan after infusion of the potent OATP inhibitor rifampicin (9 mg/kg i.v.). The transfer constant (kuptake) of [11C]glyburide from blood to the liver was estimated using the integration plot method. The tissue exposure of [11C]glyburide was described by the area under the time-activity curve (AUC) and corresponding tissue/blood ratio (AUCR). [11C]glyburide was barely metabolized in both the baseline and rifampicin conditions. Parent (unmetabolized) [11C]glyburide accounted for > 90 % of the plasma radioactivity. Excellent correlation was found between radioactive counting in arterial blood samples and in the image-derived input function, in both the baseline and rifampicin conditions (R2 = 97.9 %, p < 0.01). [11C]glyburide predominantly accumulated in the liver. Rifampicin decreased liver kuptake by 77.3 ± 7.3 %, which increased exposure in blood, kidneys, spleen, myocardium and brain (p < 0.05). No significant change in AUCR was observed except in the liver (p < 0.01). [11C]glyburide benefits from metabolic stability and high sensitivity to OATP inhibition which enables quantitative determination of OATP function. DWB-PET suggests negligible role for non-hepatic OATPs in controlling the tissue distribution of [11C]glyburide.
Le texte complet de cet article est disponible en PDF.Graphical Abstract |
Highlights |
• | Organic Anion-Transporting Polypeptides (OATP) form a family of influx transporters. |
• | Importance of hepatic and non-hepatic OATP on drug delivery in humans is not known. |
• | Whole-body PET imaging using the OATP substrate 11C-glyburide was performed in humans. |
• | 11C-glyburide benefits from unmet imaging properties to explore OATP function in humans. |
• | PET data suggest a liver-selective importance of OATP in controlling drug delivery. |
Abbreviations : ABC, AUC, AUCR, BBB, BCRP, Cblood,t, Cliver,t, COVID-19, CT, DDI, DILI, DWB, fb, HPLC, IDIF, kuptake, MR, MRAC, OATP, OAT, OCT, P-gp, PET, PK, SD, SUV, SUVmax, SLC, SUR1, TAC, UV, VE, VOI, WBPK
Keywords : [11C]glyburide, Hepatocyte, Liver, PET, Pharmacokinetics, Positron emission tomography, Transporters
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Vol 156
Article 113994- décembre 2022 Retour au numéroBienvenue sur EM-consulte, la référence des professionnels de santé.
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