Figure 2.

(A) The perifusion of islets isolated from a deceased donor with a 5-year duration of T1D. Insulin release is appropriate in response to change from low glucose (G; 3 mM) to high glucose (G; 16.7 mM), and to phosphodiesterase inhibition with 3-isobutyl-1-methylxanthine (IBMX, 0.1 mM) and membrane depolarization with KCl, albeit at the markedly reduced magnitude. Glucagon release is appropriate in response to amino acid mixture (AAM, 4.0 mM), IBMX, and KCl, but paradoxically increased (failed suppression) in response to change from low to high glucose. (B) Imaging mass cytometry of pancreatic sections from the same deceased donor demonstrates the presence of few islets with normal numbers of β cells (green) and more representative islets containing α (red) and δ (blue) but no β cells. Data are available at https://hpap.pmacs.upenn.edu.