Ghrelin and Beta Cell Function in Diabetes

Ghrelin is a hormone naturally produced in the stomach and the gut. The purpose of this research study is to determine the role of this gut hormone in the regulation of insulin secretion from the pancreas and glucose disposal after we eat. The investigators hypothesize that ghrelin has an effect on the pancreas and on how our body handles glucose after we eat. The investigators will compare insulin secretion and glucose changes during meal ingestion while either acyl ghrelin (AG) or saline (salt solution) is being infused through your vein on separate study days. AG is a form of the ghrelin hormone that has a small modification to it that allows it to bind to a specific receptor. The investigators hypothesize that AG has an effect on how the body handles glucose after a meal. AG has been approved by the U.S. Food and Drug Administration (FDA) for human research only. This study will also involve the use of a medicine called arginine, which is a naturally occurring product and found in many nutritional supplements. Its use in this study is investigational. The use of arginine helps maximize insulin release from the pancreas so the investigators can better examine whether AG affects insulin secretion.