<prompt> Which of the following directly inhibits insulin secretion?Alpha2-adrenergic agonistBeta2-adrenergic agonistCholecystokininGlucagon  <response>: Alpha 2-receptor agonists directly inhibit pancreatic insulin secretion. Beta2-adrenergic agonists stimulate insulin secretion. Cholecystokinin is a hormone that not only causes gallbladder contraction, but also causes insulin secretion from the pancreas. Pancreatic glucagon release acts as a paracrine stimulus for insulin secretion. Ref: Barrett K.E., Barman S.M., Boitano S., Brooks H.L. 2012. Chapter 25. Overview of Gastrointestinal Function Regulation. In K.E. Barrett, S.M. Barman, S. Boitano, H.L. Brooks Eds, Ganongs Review of Medical Physiology, 24e. 