“…Primary antibodies were: guinea pig polyclonal anti-swine insulin (A0564; DAKO, Carpinteria, CA, USA); mouse monoclonal anti-human/ mouse glucagon (MAB1249, clone 181402; R&D Systems, Abingdon, UK); rat monoclonal anti-somatostatin (ab30788; Abcam, Cambridge, UK); rabbit polyclonal anti-GLP-1 (ab22625; Abcam), which reacts with the mid to C terminal region of GLP-1 [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19], enabling immunoreactivity with N terminal truncated and C terminally extended forms of GLP-1; mouse monoclonal anti-GLP-1 (HYB 147-06; BioPorto Diagnostic, Gentofte, Denmark), which is specific for the amidated C-terminus of the peptide [20]; and rabbit polyclonal antibody to PC1/3 and PC2 (Chemicon, Rosemont, IL, USA). Secondary antibodies were: Alexa Fluor 488: goat anti-guinea pig IgG, goat anti-rabbit IgG, and goat anti-mouse IgG; and Alexa Fluor 594: goat anti-mouse IgG and goat antirabbit IgG (all from Invitrogen, Molecular Probes, Leiden, the Netherlands).…”