User:Xenia0418/Xenin

Xenin
Surpassed by insulin, xenin reflects the second highest degree of homology traced along the evolutionary tree among the regulatory peptides, indicating its prominent structural conservatism. Like gastric inhibitory polypetide, Xenin is secreted from the specific enteroendocrine cells called K-cells in stomach and duodenum of upper gut. Overnight worker––who had lower insulin sensitivity and increased adiposity from disrupted hemostasis–­–exhibited a slow postprandial increase in their anorexigenic xenin level, while a suppression in their orexigenic ghrelin level. Xenin promotes insulin release by gastric inhibitory polypetide to regulate glucose homeostasis. This effect is not observed in type 2 diabetes patients when using a dosage of 4 pmol ⋅kg−1⋅min−1. However, a separate study utilizing the infusion at higher dosages of xenin underlines its effective reduction of postprandial glucose level even in humans with type 2 diabetes. Its increase of insulin secretion is indirect and would not produce any effects by itself. After activating neurotensin receptor-1, xenin leads to an increase in the cytosolic calcium concentration and acetylcholine release of some myenteric neurons.