Pancreatic δ cells are resistant to auto- and paracrine inhibition in human type-2 diabetes.

In human type-2 diabetes, pancreatic δ cells show impaired inhibition by somatostatin and adrenaline, linked to reduced SSTR2 surface expression.

• Why it matters: Intraislet somatostatin normally restrains α- and β-cell activity, but δ-cell regulation in type-2 diabetes is unclear because intrinsic control is hard to separate from paracrine effects.
• What they did: Isolated δ cells from cadaveric nondiabetic and type-2 diabetic donors were compared using single-cell total internal reflection microscopy, electrophysiology, and secretion measurements.
• The result: Elevated glucose stimulated somatostatin exocytosis in both groups, but δ-cell inhibition by somatostatin and adrenaline was impaired in type-2 diabetes, suggesting dysregulated intraislet somatostatin signaling.