Figure 9.

Tissue from the head region of a human pancreas to demonstrate differences in islet structure in the PP-rich lobule of the ventral pancreas. Immunoperoxidase labelling for glucagon (A) and PP (B). Adjacent sections through the head region show an exocrine lobule (outlined), which has large, diffuse islets containing a high proportion of PP-positive cells. An islet in an adjacent lobule (arrow) has no PP-cells and the usual population of glucagon-positive cells. The lower panel shows immunofluorescent labelling for (C) PP (green), (D) glucagon (red), (E) insulin (blue), and merged images (F). The diffusely structured islet contains mostly PP-positive cells, a single glucagon-positive cell (arrow), and insulin-positive cells distributed randomly throughout. Scale (A, B) 500 μm; (C, D, E, F) 50 μm.