1P-48（1A-O1-1625） PDF
Development of quantitative analysis for insulin in pancreatic islet by imaging mass spectrometry and application to evaluation of diabetic model mice
Imaging mass spectrometry (IMS) enables to visualize the distribution of various molecules without labeling by ionizing a lot of molecules on tissue sections using a mass spectrometer. We previously reported the quantitative analysis approach for tissue distribution of drugs by matrix-assisted laser desorption/ionization (MALDI)-IMS. In this study, we firstly investigated development of the methodology to detect insulin, the model molecule of endogenous macromolecule, on pancreas sections of normal mice by MALDI-IMS. However, it was necessary for the specific fragmented peptides of mouse insulin-1 and 2 produced by enzyme digestion to detect them by MALDI-LTQ-XL. Endoproteinase Glu-C (V8 Protease) was selected as the optimal enzyme for detection the specific fragmented peptides of mouse insulin-1 and 2.
Next, we established the quantitative analysis of insulin concentration in pancreatic islet of mice by MALDI-IMS. To quantify insulin concentration in islets on pancreas sections of mice, the calibration curve using human insulin was prepared. Additionally, porcine insulin was used as an internal standard to improve quantitative analysis precision of mouse insulin on pancreas sections measured by MALDI-IMS.
Finally, we would like to introduce the localization and quantitative analysis of insulin on pancreas sections of diabetic model mice using this quantitative MALDI-IMS method.