GLP1R and Glucose intolerance: For example, lean chow-fed Glp1r βcell–/–:Gcgrβcell–/– mice exhibit normal oral and IP glucose tolerance as compared to wild-type controls; however, metabolically stressed Glp1rβcell–/–:Gcgrβcell–/– mice exhibit impaired oral and IP glucose intolerance as compared to HFD-fed controls (6).