| Primary Identifier | IPR015523 | Type | Family |
| Short Name | VIP |
| description | A number of polypeptidic hormones, mainly expressed in the intestine or the pancreas, belong to a group of structurally related peptides [, ]. Once such hormone, glucagon is widely distributed and produced in the alpha-cells of pancreatic islets []. It affects glucose metabolism in the liver []by inhibiting glycogen synthesis, stimulating glycogenolysis and enhancing gluconeogenesis. It also increases mobilisation of glucose, free fatty acids and ketone bodies which are metabolites produced in excess in diabetes mellitus. Glucagon is produced, like other peptide hormones, as part of a larger precursor (preproglucagon) which is cleaved to produce glucagon, glucagon-like protein I and glucagon-like protein II []. The structure of glucagon itself is fully conserved in all known mammalian species []. Other members of the structurally similar group include glicentin precursor, secretin, gastric inhibitory protein, vasoactive intestinal peptide (VIP), prealbumin, peptide HI-27 and growth hormone releasing factor.Pituitary adenylate cyclase-activating polypeptide (PACAP) is a bioactive peptide that was originally isolated from ovine hypothalamus on the basis of its ability to stimulate adenylate cyclase in rat anterior pituitary cell cultures. It is a neuropeptide of the vasoactive intestinal peptide/secretin/glucagon superfamily. Studies in two related patients with a partial trisomy 18p revealed three copies of the PACAP gene and elevated PACAP concentrations in plasma []. PACAP appears to function as an emergency response co-transmitter in the sympathoadrenal axis, where the primary secretory response is controlled by a classical neurotransmitter but sustained under paraphysiological conditions by a neuropeptide[].Vasoactive intestinal peptide (VIP), a 28-amino acid peptide originally isolated from porcine duodenum, is present not only in gastrointestinal tissues but also in neural tissues, possibly as a neurotransmitter, and exhibits a wide variety of biologic actions []. Two principal groups of receptors orthologous with human PAC1R and VPAC1R and were identified and characterised at the genomic level in the fish Fugu rubripes (Japanese pufferfish). |
