We thank Dr. Chhabra and Dr. Lazartigues for their thoughtful comments on the role of ACE type 2 (ACE2) in glycemic control (1). In db/db mice or in C57Bl/6J mice infused with angiotensin II, their group has shown that ACE2 can help protect against hyperglycemia by promoting pancreatic insulin secretion (2,3). We found that deficiency of ACE2 causes impaired insulin sensitivity of mice treated with angiotensin II infusion or a high-calorie diet (4). Thus, ACE2 appears to play a multifunctional role in maintaining glucose homeostasis by regulating both insulin secretion and insulin sensitivity.

The counterregulating …