Fig. 2. Tirzepatide stimulates insulin secretion through both the GLP-1R and GIPR in human islets.
a, Islet perifusion from one set of human islets. Insulin secretion was measured in response to 30 nM tirzepatide in the presence of Ex9 (1 μM), a GIPR antagonist (GIPR ant) or both. n = 3 per group. b, iAUC values for insulin secretion in response to tirzepatide in eight individual sets of human islets. The dashed line indicates the level of glucose-stimulated insulin secretion before tirzepatide stimulation. n = 3 per group. c, Summary data of all eight experiments in human islets. Each individual experiment was averaged to produce a single data point for each condition and expressed as a relative value to control conditions. Individual experiments have connecting lines. n = 8. All values are mean ± s.e.m. The statistical test was one-way ANOVA with Tukey’s post-hoc test (b,c).