t is controversial whether the number of glucagon receptors is altered in diabetic states. Most studies, however, appear to suggest that the number of glucagon receptors is reduced in diabetic subjects. Interestingly, even in the presence of fewer glucagon receptors, the ability of glucagon to stimulate cAMP production may remain unchanged or even be elevated (12). This may be at least partially explained by the observation that the activation of adenylate cyclase by glucagon involves only 20% of glucagon receptors