GCG and type 1 diabetes mellitus: In three conflicting studies (Figure 7), T1D decreased basal AC activity and the AC‐activating responsiveness to increasing concentrations of glucagon (Dighe et al., 1984), had no effect on basal activity but increased the responsiveness to glucagon (Lynch et al., 1989), or decreased basal activity but had no effect on responsiveness to glucagon (Srikant et al., 1977).