摘要:
P-glycoprotein (P-gp) is an ATP-dependent efflux pump protecting the body against xenobiotics. The in vitro characterized modulator 6,7-dimethoxy-2-(6-methoxy-naphthalen-2-ylmethyl)-1,2,3,4-tetrahydroisoquinoline (MC80) of the P-gp pump was labelled with C-11 and evaluated in vivo for its potential to image P-gp function and expression. Radiochemical pure (>98%) [C-11] MC80 was obtained within 25 min starting from [C-11] methyl iodide with radiochemical yield of 26%. Biodistribution studies in FVB mice demonstrated a high baseline brain uptake (7.66 +/- 1.38% ID/g at 1 min pi). Cerebral uptake was increased in mdr1a knock-out mice as well as after CsA pretreatment. Pre-administration of an excess of non-radioactive MC80 caused a reduced uptake in several target organs including brain, pancreas and intestines. The results indicate that [C-11] MC80 kinetics are modulated by P-gp. Reversesd phase-HPLC analysis of brain revealed an excellent metabolic profile (>90% intact [C-11] MC80). (C) 2010 Elsevier Ltd. All rights reserved.