Figure 2.

Vascular trees are preserved in living human and mouse pancreas slices. (A, B) Maximal projection of confocal images of living human pancreas slices stained with calcein-AM (to visualize live cells, green) and with ethidium homodimer-1 (to visulize dead cells, red). Islet endocrine cells can be seen using the backscatter signal (white, left panel in B). The majority of the pancreatic tissue is alive in slices. (C) Vascular trees in living human (left panel) and mouse (right panel) living pancreas slices. Human slices were incubated with a fluorescent lectin (from Lycopersicon esculentum) to label blood vessels (red), while the lectin was injected intravenously in the mouse before extracting the pancreas. The islet microvasculature is preserved in living pancreas slices. Arrows point to islet feeding arterioles. (D) Living human pancreas slices can be incubated with membrane permeable calcium indicators (e.g., Fluo4, green) and fluorescent lectins (red) to simultaneously monitor changes in islet endocrine cell or vascular cell activity. Scale bars = 40 μm (A–C) and 10 μm (D).