<Li> PP cells (gamma cells) producing pancreatic polypeptide (<5%) </Li> <Li> Epsilon cells producing ghrelin (<1%) </Li> <P> It has been recognized that the cytoarchitecture of pancreatic islets differs between species . In particular, while rodent islets are characterized by a predominant proportion of insulin - producing beta cells in the core of the cluster and 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 . </P> <P> 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). </P>

Which cells with in the islets of langerhans secrete insulin