Nozomi Takai, Yukari Tanaka, Kazuhiro Inazawa and Hideo Saji
Rapid Commun Mass Spectrom. (2012), 26(13), 1549-1556
RATIONALE: Recently, the requirement for a quantitative research method using imaging mass spectrometry (IMS) to be developed has been discussed. Specifically, the simultaneous quantification of a drug in multiple organs by using whole-body sections could be insightful for the pharmaceutical industry in the study of drug distribution.
METHODS: Frozen whole-body sections were obtained from mice injected with raclopride, a dopamine D2 receptor selective antagonist, and coated with a matrix-assisted laser desorption/ionization (MALDI) matrix compound. The whole-body sections were then analyzed using a linear ion trap mass spectrometer equipped with a MALDI source. The concentration of raclopride in each tissue was determined using liquid chromatography/tandem mass spectrometry (LC/MS/MS).
RESULTS: The IMS-based signal intensity of raclopride strongly correlated with the concentration of the drug in the tissue samples (R = 0.94; p <0.001) of six different organs. Furthermore, the spatial information obtained by IMS was very similar to that obtained by autoradiography, which is a traditional technique used for the study of drug distribution.
CONCLUSIONS: This study suggests that IMS enables the quantitative analysis of drug distribution in multiple organs simultaneously. In addition, it enhances ideal drug candidate selection in terms of efficient evaluations.