ADRB2 and type 2 diabetes mellitus: In addition, we and others have also shown that β2-AR stimulation, using a relatively high dosage of the β2-AR agonist clenbuterol, improved glucose tolerance in diet-induced obese (DIO) mice [2], Goto–Kakizaki rats [2] and Zucker fatty rats [4]—well-established rodent models for human type 2 diabetes.