Leptin cotherapy does not alter circulating insulin levels or β-cell recovery. A: The 4-h fasted plasma insulin levels were measured 6 weeks after transplant in all groups by ultrasensitive insulin ELISA.
Limit of detection (0.019 ng/mL) is shown as horizontal broken line (n = 3–5). B: Immunofluorescent quantifications of β-cell and α-cell areas were performed in nondiabetic controls and STZ-induced diabetic
mice treated with 125 islets (125 islets-vehicle), with 125 islets and leptin (125 islets-leptin), or left untreated (sham-vehicle)
(n = 3–4). Data are presented as mean ± SEM. †P < 0.05 vs. nondiabetic controls. ‡P < 0.05 vs. sham-vehicle controls. C: Representative images of pancreata from nondiabetic and sham-vehicle groups costained for insulin (red), glucagon (green),
and DAPI (white) (n = 3–4). Scale bars represent 1,000 µm (left top, left bottom) and 100 µm (right top, right bottom). NS, not significant.