Figure 5

Model-calculated insulin concentrations in response to increasing glucose concentrations. Calculated insulin concentrations for two illustrative free and encapsulated islets (left and right, respectively; d = 100 (top) & 150 μm (bottom), l _caps = 150 μm) under normoxic conditions. Data shown as surface plot are insulin concentration (color-coded from blue for low to red for high. Streamlines show the flow of the perifusion fluid (color-coded for velocity; flow from left to right) and colored contour lines show isolevels for the perifusing glucose (from light blue for low to light red for high). Model calculated values are shown during the increase of the glucose concentration from 3 mM to 11 mM; first phase response is noticeably delayed and blunted in the encapsulated islet.