P-glycoprotein function at the blood-brain barrier in humans can be quantified with the substrate radiotracer 11C-N-desmethyl-loperamide.

ABSTRACT:

Unlabelled

Permeability-glycoprotein (P-gp), an efflux transporter in several organs, acts at the blood-brain barrier to protect the brain from exogenous toxins. P-gp almost completely blocks brain entry of the PET radiotracer (11)C-N-desmethyl-loperamide ((11)C-dLop). We examined the ability of (11)C-dLop to quantify P-gp function in humans after increasing doses of tariquidar, an inhibitor of P-gp.

Methods

Seventeen healthy volunteers had a total of 23 PET scans with (11)C-dLop at baseline and after increasing doses of tariquidar (2, 4, and 6 mg/kg intravenously). A subset of subjects received PET with (15)O-H(2)O to measure cerebral blood flow. Brain uptake of (11)C-dLop was quantified in 2 ways. Without blood data, uptake was measured as area under the time-activity curv

SUBMITTER: Kreisl WC 

PROVIDER: S-EPMC2856602 | biostudies-literature | 2010 Apr

REPOSITORIES: biostudies-literature