Decreased blood pressure with acute administration of quercetin in L-NAME-induced hypertensive rats.

Quercetin is known to reduce blood pressure (BP); however, its acute effects are unclear. We investigated the acute effects of quercetin on BP, aortic mechanical properties and vascular reactivity in female Sprague-Dawley (SD) rats. Hypertension was induced using L-NAME (40 mg/kg/day).

MS1-Based Data Analysis Approaches for FFPE Tissue Imaging of Endogenous Peptide Ions by Mass Spectrometry Histochemistry (MSHC).

Ambiguous reports in the literature exist regarding the use and usefulness of formalin-fixed paraffin-embedded (FFPE) tissues in mass spectrometry imaging (MSI). Especially for the study of endogenous (non-tryptic) peptides, several studies have concluded that MSI on archived FFPE tissue bank samples is virtually impossible. We here illustrate that by employing a variant of MSI, called mass spectrometry histochemistry (MSHC), biomolecular tissue localization data are obtained that unequivocally comprise endogenous peptides.

HistoSnap: A Novel Software Tool to Extract m/z-Specific Images from Large MSHC Datasets.

We describe an informatics tool for comfortable browsing through highly complex, multi-gigabyte mass spectrometry histochemistry (MSHC) datasets, via clever ion-specific image extraction.The package is developed particularly for the untargeted localization/discovery of biomolecules such as endogenous (neuro)secretory peptides on histological sections of biobanked formaldehyde-fixed paraffin-embedded (FFPE) samples straight from tissue banks.Atmospheric pressure-MALDI-Orbitrap MSHC data of sections through human pituitary adenomas in which two well-known human neuropeptides are detected are used as an example to demonstrate the key features of the novel software, named HistoSnap.

Spatially Resolved Neuropeptide Characterization from Neuropathological Formalin-Fixed, Paraffin-Embedded Tissue Sections by a Combination of Imaging MALDI FT-ICR Mass Spectrometry Histochemistry and Liquid Extraction Surface Analysis-Trapped Ion Mobility Spectrometry-Tandem Mass Spectrometry.

To make the vast collections of well-documented human clinical samples archived in biobanks accessible for mass spectrometry imaging (MSI), recent developments have focused on the label-free top-down MS analysis of neuropeptides in sections of formalin-fixed, paraffin-embedded (FFPE) tissues. In analogy to immunohistochemistry (IHC), this variant of MSI has been designated MSHC (mass spectrometry histochemistry). Besides the detection and localization of neuropeptide and other biomolecular MS signals in these FFPE samples, there is great interest in their molecular identification and full characterization.