FIG. 5.

Unique association between α- and β-cells in pancreatic islets. Pancreatic islets labeled for glucagon (green) and insulin (red) are shown at low magnification (A and D). Boxed areas are shown at higher magnification in B and E. α- and β-cells lining vascular channels in B are depicted in C. α- and β-cells lining the islet mantle in E are depicted in F. Arrowheads point to cytoplasmic extensions of β-cells that span α-cells. Scale bars, 10 μm in A and D, and 5 μm in B and E. Heterologous contacts between β- and α-cells (beta-alpha) and homologous contacts between α-cells (alpha-alpha) and β-cells (beta-beta) around empty areas were scored. Their relative frequencies are shown in G. Columns are means ± SEM; n = 52 islets from 10 pancreata. (A high-quality digital representation of this figure is available in the online issue.)