β<sup>low</sup>-cells have an altered cAMP signaling.

<p>Effects of 5.5 mM and 16.7 mM glucose±10 nM GLP-1 on insulin release (A) and cAMP content (B) in β<sup>high</sup> and β<sup>low</sup>-cells assessed by static incubation experiments (n = 3–5). (C) Effects of 5.5 mM and 16.7 mM glucose±5 mM db-cAMP on insulin secretion in β<sup>high</sup> and β<sup>low</sup>-cells (n = 3–5). n represents the number of independent cell preparations from 6 pooled rats each. Data are means±SEM. *, p<0.05 and **, p<0.01.</p>