Beneficial effects of intercellular interactions between pancreatic islet cells in blood glucose regulation

A role for islet somatostatin in mediating sympathetic regulation of glucagon secretion

“…6,12,13 It has been suggested that the tonic inhibitory input from the δ-cells in response to nutrient stimuli may prevent wasteful co-secretion of insulin and glucagon. 14 In conclusion, our studies using Sst -/-islets suggest that paracrine interactions between δ-and α-cells provide an intra-islet, SST-mediated control mechanism which facilitates and fine-tunes the release of glucagon in response to sympathetic activation.…”

Development, growth and maintenance of β-cell mass: Models are also part of the story

“…To unravel the mechanism of interaction between insulin, glucagon and somatostatin, Jo et al (Jo et al, 2009) proposed a compartmental mathematical model of α-, β-, and δ-cells. In the model, each compartment can take one of two states: active and silent.…”

Mathematical models for insulin secretion in pancreatic β-cells

“…[112][113][114][115][116] Their complex behaviors, however, may not obviously be addressed by probing α-, β-and δ-cells separately. Even if they are not physically connected with each other, they communicate with each other via paracrine interactions which are mediated by hormones [117][118][119][120] or neurotransmitters.…”

“…On the other hand, the role of δ-cells is not fully known although there are reports that somatostatin secreted from δ-cells inhibits both α and β-cells. [127][128][129][130] In conclusion, despite both theoretical and experimental efforts as to the questions over the past 30 y, [112][113][114][115][116]127,128,131 there still lacks concrete understanding of the roles of the paracrine interactions among islet cells in glucose homeostasis. A variety of complicated interactions in an islet makes it difficult to recognize their roles, and existing experiments have focused mostly on static responses of the endocrine cells.…”

“…70,[144][145][146] It is also claimed that the β-cell oscillatory behaviors are generated via multiple-component mechanism, rather than single-component and collaborators constructed a simple mathematical model for an islet consisting of α-, β-and δ-cells, incorporating experimentally known interactions between islet cells. 112 The mathematical model proposed by them could systematically include all the cellular interactions and identify their effects on static and/ or dynamic responses to external glucose changes. It also takes individual heterogeneities into consideration, e.g., in glucose sensitivity.…”