Whole-body tissue section

Stoeckli M, Staab D, Schweitzer A. Compound and metabolite distribution measured by MALDI mass spectrometric imaging in whole-body tissue sections. Int. J. Mass Spectrom. 2006 260 195-202. 

Compounds that fluoresce under ultraviolet light can be visualized in the tissue sections and their locations recorded with color film. Whole-body tissue sections can be used for histochemical localizations for comparison with the autoradiograms. Furthermore, the areas can be removed, extracted, and the extract chromotographed to identify the chemical nature of the radioactivity revealed by the autoradiogram. 

Stoeckli, M., Knochenmuss, R., McCombie, G., Staab, D., and Rohner, T. (2005). MALDI-MSI of compounds and metabolites in whole-body tissue sections. In Proceedings of the 53rd ASMS Conference on Mass Spectrometry and Allied Topics, San Antonio, TX. 

Trim P, Henson C, Avery J, McEwen A, Snel M, Claude E, Marshall P, West A, Princivalle A, Clench M (2008) Matrix-assisted laser desorption/ionization-ion mobility separation-mass spectrometry imaging of vinblastine in whole body tissue sections. Anal Chem 80 8628-8634. doi 10.1021/ac8015467... 

Analysis of Whole-Body Tissue Sections Utilizing Mass Spectral Imaging... 

In the same fashion, IMS can be used to discriminate against potential isobaric species to improve analyte specificity in MSI experiments. Trim et al. (2008) demonstrated the utility of IMS to enhance detection of vinblastine in whole-body tissue sections. Sprague—Dawley rats were dosed intravenously with vinblastine, after which they were sacrificed 1 h postdose. After preparing the tissue section, the samples were analyzed on a QqTOF in MS/MS mode. CID occurred after the ions were separated by IMS, thus product ions can be... 

FIGURE 15.14 Tissue imaging using DESI—MS/MS and autoradiography in mice dosed with propranolol, (a) Scanned optical image of a 40-pm-thick sagittal whole-body tissue section of a mouse dosed intravenously with 7.5 mg/kg propranolol and euthanized 60 min after dose, (b) Distribution of propranolol in the 94 mm X 30 mm tissue section presented in (a) measured by DESI—MS/MS. [Reprinted from Kertesz et al. (2008) with permission of American Chemical Society.]... 

Fig. 17.1. Generation of whole-body tissue sections from fresh frozen mouse pups. Photomicrographs of (a, c) a 3-day-old pup frozen in a block of ice from which 15-p.m thick sections were cut using a whoie-body cryostat and mounted on conductive glass slides using the CryoJane system (b, d) a 1-day-old pup held into position using OCT from which 12-p.m thick sections were cut in a biological specimen cryostat and directly thaw-mounted on conductive glass slides. See text for details.

The resulting crystalline film of matrix is fairly homogeneous (Fig. 17.4b) and allows imaging by MALDI MS with spatial resolutions as small as 30 p,m (13). Further, because of its simplicity, this matrix coating technique is easily applicable to larger whole-body tissue sections. Since matrix is applied dried on the section, this eliminates any risks of analyte delocalization. 

MALDI-MSI has been demonstrated to be a suitable technique in pharmaceutical research for providing information of the distribution of low molecular weight compounds such as drugs and their metabolites within whole-body tissue sections. Important ADME information can be determined by MALDI-MSI analysis of the distribution of drugs and metabolites in whole-body tissue sections taken from animals killed at a range of time points postdose. In this example we applied MALDI-MSI to the localization of a compound and its primary metabolite in whole-body mouse sections. 

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