SSTR5 antagonism increases GLP-1 levels in a non-glucose-dependent manner in normal mice. (a, b) Effects of S5A1 on active GLP-1 levels over 12 hours in normal mice after an overnight fast. (c) Unbound plasma exposure of S5A1 over 12 hours. Data shown as mean ± standard error of the mean from five mice per group. ***P < 0.001. con, concentration.