Intestinal glucagon-like peptide-1: A new player associated with impaired counterregulatory responses to hypoglycaemia in type 1 diabetic mice

Figure 4 Intestinal glucagon-like peptide-1 inhibits glucagon secretion through endocrine effects. A: Immunohistochemistry showing pancreatic glucagon-like peptide-1 receptor (GLP-1R) levels, with GLP-1R in brown. Bars = 20 μm; B: Immunofluorescence staining showing somatostatin (SST) + cAMP expression in the pancreas, with SST in green, cAMP in red, and cell nuclei in blue. Bars = 20 μm; C: Pancreatic SST⁺ cell area; D: CAMP integrated optical density (IOD) in pancreatic δ cells; E: Enzyme-linked immunosorbent assay results showing changes in plasma SST levels; F: Immunofluorescence staining showing GCG + cAMP expression in the pancreas, with GCG in green, cAMP in red, and cell nuclei in blue. Bars = 20 μm; G: Pancreatic GCG+ IOD; H: CAMP IOD in pancreatic α cells. All the data are presented as the mean ± SE. ^aP < 0.01 vs diabetic mice; ^bP < 0.01 vs diabetic mice with a single hypoglycemic episode (DH1); ^dP < 0.05 vs DH1 group; DM: Diabetic mice; DH1: Diabetic mice with a single hypoglycemic episode; DH5: Diabetic mice with five hypoglycaemic episodes; GLP-1: Glucagon-like peptide-1; GLP-1R: Glucagon-like peptide-1 receptor; IOD: Integrated optical density.