Figure 3. Insulin and glucagon secretion in islets from healthy and GADA⁺ donors.

(A) The dynamics of insulin secretion during different interventions. (B) The dynamics of glucagon secretion. (C) Magnified view of a selected section (53–100 min) of the data from B highlights the difference in glucose suppression of glucagon secretion between normal and GADA⁺ islets. (D–G) Total glucagon secretion during 3 mM glucose (D), 16.7 mM glucose (E), G16.7 plus IBMX treatment (F), and KCl treatment (G) calculated as the AUC. (H–K) Islets from the same preparations were assessed by perifusion assay at Vanderbilt (see Supplemental Figure 2, A and B). AUC analysis of glucagon responses to high glucose (H), c-AMP–mediated secretion in response to IBMX (I), and epinephrine (J), and an unaltered KCl response (K). *P < 0.05 and **P < 0.01, by unpaired two-tailed t test. EQs, islet equivalents.