Glucose exposure pattern determines glucagon-like peptide 1 receptor expression and signaling through endoplasmic reticulum stress in rat insulinoma cells

► We study GLP-1 receptor expression and its consequences by glucose exposure pattern. ► Glucose fluctuation reduces GLP-1 receptor level more than chronic hyperglycemia. ► It induces more adverse ER stress and cytotoxicity in β-cells. ► GLP-1-induced calcium influx and insulin secretion are reduced by glucose fluctuation.