Pancreatic islets by scarce alpha, delta and PP cells in the periphery, human islets display alpha and beta cells in close relationship with each other throughout the cluster. Islets can influence each other through paracrine and autocrine communication, and beta cells are coupled electrically to six to seven other beta cells (but not to other cell types). The paracrine feedback system of the pancreatic islets has the following structure: A large number of G protein-coupled receptors (GPCRs) regulate the secretion of insulin, glucagon and somatostatin from pancreatic islets, and some of these GPCRs are the targets of drugs used to treat type-2
Chain Islets Chain Islets The Chain Islets and Great Chain Island (occasionally Great Chain Islet) are a group of at least 18 islets situated off the east coast of Oak Bay, British Columbia, Canada. They lie in Mayor Channel about halfway between Mary Tod Island (W) and Discovery Island (E). Most of the islets are very small, rocky, and are unnamed, except for Great Chain Island which is covered in grass and herbaceous cover with occasional shrub thickets. The islets are noted as an important gathering place for harbor seals in the summer and for many seabirds such as seagulls and cormorants.