Fig. 2.

MIP-Luc-VU mice have normal glucose tolerance, insulin secretion, and islet morphology. a Intraperitoneal glucose tolerance testing of MIP-Luc-VU animals (black squares) revealed similar response to a glucose bolus (1.5 g/kg body weight) as wild-type control animals (open circles; n=5 each group). b Isolated MIP-Luc-VU islets (black squares) displayed similar insulin release in response to islet secretagogues as islets isolated from wild-type animals (open circles) when tested in a cell perifusion apparatus (n=4 each group). The time of exposure to each islet secretagogue (16.8 mM glucose, 16.8 mM glucose+ 100 μM isobutyl methyl xanthine, and 2.8 mM glucose+300 μM tolbutamide) is indicated by the bar above the chart. Immunocytochemistry of MIP-Luc-VU islets stained for insulin (green), glucagon (red), and somatostatin (blue) (c); insulin (d); luciferase (e); and insulin (green) and luciferase (red) (f). This pattern of expression of luciferase was similar in different mice. There was not a significant difference between the number of luciferase-positive beta cells in the STZ control cohort (four mice, approximately 60 islets/mouse) and high-fat control cohort (three mice) as determined by unpaired t test (P=0.5654)—see Figures 4 and 5.