Evidence for a direct role of GLP-1 mimetic action in α-cell hyperplasia. Images of pancreatic sections (A–F) are provided to illustrate a similar pattern of α-cell hyperplasia in the donor treated with exenatide (6189) as in the
sitagliptin-treated donors, implying a role for GLP-1 action independent of DPP-4 inhibition in α-cell hyperplasia. Enlarged
and often eccentrically shaped islets are apparent, as well as increased numbers of glucagon immunoreactive cells associated
with and surrounding ductal structures.