[Calcitonin gene-related peptide in diabetes mellitus type 2: a possible etiopathogenetic role].
The Calcitonin Gene-Related Peptide (CGRP) is a 37 aminoacid peptide displaying about 50% homology with amylin which is secreted from the pancreatic islets of Langerhans. The main form, the beta-CGRP, is produced by the enteric nervous system and perivascular nerves of the vasa vasorum. It represents the most powerful vasodilator yet discovered but its role is not yet completely clarified. Recently it has been implicated in the control of regional blood flow and some authors have hypothesized its role in the development of Non Insulin Dependent Diabetes Mellitus (NIDDM). CGRP and amylin seem to inhibit the release of insulin from beta-cells and to play a role in local paracrine control of insulin secretion. In addition it is also shown to decrease the uptake of glucose by striated muscle. This has led to the suggestion that CGRP might be a circulating hormone implicated in the regulation of peripheral insulin sensitivity. In this review we examine the possible role of CGRP in the development of peripheral insulin resistance and altered insulin secretion which is characteristic of NIDDM.