Fig. 1.

Increases in islet size in response to high insulin demand in the ob/ob mouse pancreas. (A) Representative morphological appearance of a 4-mo-old ob/ob mouse (Left) compared with a control littermate (Right), showing a strong obese phenotype. (B) Fasted body weight of ob/ob and control mice at different ages shows a rapid increase in body mass in the ob/ob mice. (C) Fasted blood glucose and plasma insulin levels in 3-mo-old ob/ob and control mice. (D and E) Image montages of 5-µm-thick sections of 8-mo-old ob/ob (D) and control littermate (E) pancreata, stained with H&E. Note the staining of islet sections in light gray. (Insets) Magnified views of typical islet dimensions and morphology. B and C show values for mixed males and females (n = 5 males + 4 females for ob/ob; n = 5 males + 5 males for control littermates). Values are average ± SEM. **P < 0.01; ***P < 0.001. (Scale bar: 1 mm; inset dimensions, 1 mm × 1 mm.)