Human brain imaging and radiation dosimetry of 11C-N-desmethyl-loperamide, a PET radiotracer to measure the function of P-glycoprotein.

ABSTRACT:

Unlabelled

P-glycoprotein (P-gp) is a membrane-bound efflux pump that limits the distribution of drugs to several organs of the body. At the blood-brain barrier, P-gp blocks the entry of both loperamide and its metabolite, N-desmethyl-loperamide (N-dLop), and thereby prevents central opiate effects. Animal studies have shown that (11)C-dLop, compared with (11)C-loperamide, is an especially promising radiotracer because it generates negligible radiometabolites that enter the brain. The purposes of this study were to determine whether (11)C-dLop is a substrate for P-gp at the blood-brain barrier in humans and to measure the distribution of radioactivity in the entire body to estimate radiation exposure.

Methods

Brain PET scans were acquired in 4 healthy subjects for 90 min and

SUBMITTER: Seneca N 

PROVIDER: S-EPMC2792991 | biostudies-literature | 2009 May

REPOSITORIES: biostudies-literature