| Discovery | Aviptadil(VIP) is a neuropeptide consisting of 28 aa residues, withwide distribution in the central and peripheral nervous systems. VIP has a broad spectrum of biologic actions, and actsas a neurotransmitter or neuromodulator and also as ahormone. VIP was first discovered as a smooth muscle-relaxantvasodilator peptide in the lung; it was isolated from theporcine intestine in 1970. Its original label as a“candidate gastrointestinal hormone” was soon replacedby its new and apparently true identity as a neuropeptidewith neurotransmitter and neuromodulator properties. |
| Structure | VIP possesses two segments of secondary structures: arandom coil structure in the N-terminal region betweenpositions 1 and 9, and a long α-helical structure in theC-terminal region stretching from position 10 to itsC-terminus. The primary structure of VIP is highly conserved invertebrates with complete identity among mammalsexcept for the guinea pig and opossum. Mr 3326, pI >11. VIP is soluble in water to 20mg/mL.
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| Gene, mRNA, and precursor | The human VIP gene, VIP, location 6q25.2, containsseven exons. Each exon encodes a distinct functionaldomain of the VIP precursor. The VIP precursor polypeptide (preproVIP) contains several additional biologically active peptides, including peptide histidineisoleucine (PHI, found in nonhuman mammals), peptidehistidine methionine (PHM, the human equivalent ofPHI), and peptide histidine valine (PHV, a C-terminallyextended form of PHI and PHM). |
| Receptors | VIP and PACAP share a wide spectrum of biologicalactivity as well as common receptors belonging to theclass II of GPCR. Three VIP or PACAP receptor types,which are derived from different genes, are recognized,namely VPAC1, VPAC2, and PAC1. Two of these receptors, VPAC1 and VPAC2, share a high binding affinity inthe nanomolar range for VIP and PACAP. A third receptor type, PAC1, has been characterized for its high affinityfor PACAP, but low affinity for VIP. |
| Synthesis and release | Aviptadil gene expression is stimulated by dibutyryl cAMPand by increased PKC activity induced by tumorpromoting phorbol esters. When acting together, cAMPand phorbol esters synergistically stimulate VIP genetranscription via different sites on the gene. |
| Signal transduction pathway | By binding to VIP, VPAC acts on the Gs protein andactivates PKA via elevation of AC activity and production of cAMP (cAMP-dependent pathway). PKA eitherinhibits phosphorylation of the downstream MAP/ERKkinase or promotes phosphorylation of cAMP responseelement binding protein (CREB), which finally leads tothe inhibition of NF-κB. Meanwhile, studies have alsoidentified a pathway that inhibits the nuclear entry ofNF-κB through VPAC signaling, which inhibits IκB phosphorylation (cAMP-independent pathway). |
| Biological functions | VIP is extensively distributed in central and peripheraltissues, where it acts as a neurotransmitter and neuromodulator.8 The main activity of VIP is vasodilatation. VIPinduces the dilation of vessels, which results in increasedblood flow, decreased peripheral vascular resistance, andhypotension. While VIP has a suppressive effect on theintestinal smooth muscle, it exerts relaxant effects onthe lower esophageal sphincter, the sphincter of Oddi,the anal sphincter, and the bronchial smooth muscle. Inthe small intestine, VIP facilitates the secretion of electrolytes and aqueous liquid. In the stomach, it inhibits gastric secretion. In the pancreas, VIP facilitates the externalsecretion of bicarbonic acid and aqueous liquid from pancreatic epithelial cells, and facilitates enzyme secretionfrom acinar cells. VIP promotes the secretion of both insulin and glucagon in a glucose-dependent manner. VIP isbroadly distributed in the central nervous system, especially in the hypothalamus and pituitary anterior lobe,and is associated with the regulation of pituitary hormones. VIP is produced by lymphoid tissue and exertsa wide spectrum of immunological functions, controllingthe homeostasis of the immune system through differentreceptors expressed in various immunocompetent cells. VIP acts as a growth factor. It functions as a proliferativefactor in normal tissue cells as well as in cancer cells. VIPmight inhibit apoptosis by stimulating the expression ofthe apoptosis-inhibiting gene Bcl2 or by inhibiting theactivity of caspase 3. |
| Clinical implications | Various diseases have been reported to involve VIPactivity, including bronchial asthma, transmission ofpain, cluster headaches, Alzheimer’s disease, Parkinson’sdisease, and brain injury. |
| Uses | Pulmonary hypertension;Erectile dysfunction |
| Uses | Vasoactive Intestinal Peptide human, porcine, rat has been used as an immunogen to analyze the immunohistochemical reactions. It has also been used in cell migration assay. |
| General Description | Vasoactive intestinal peptide (VIP) is widely distributed inthe body and is believed to occur throughout the gastrointestinaltract. It is a 28-residue polypeptide with structuralsimilarities to secretin and glucagon. It causes vasodilatationand increases cardiac contractibility. VIP stimulates bicarbonatesecretion, relaxes gastrointestinal and othersmooth muscles, stimulates glycogenesis, inhibits gastricacid secretion, and stimulates insulin secretion. Its hormonaland neurotransmitter role has been investigated. |
| Biochem/physiol Actions | VIP (Vasoactive intestinal peptide) possesses anti-inflammatory and immunomodulatory functions. It controls the pathogenesis of rheumatoid arthritis. It is also involved in neuroblastoma differentiation, and pancreatic insulin secretion. Vip exhibits its function through G-protein coupled receptors. Some of the other important actions of VIP is associated with the digestive, respiratory, cardiovascular and reproductive systems. |
| Clinical Use | 28-peptide that is structurally related to secretin and glucagon. It has a diverse biological actions. It has orphan drug status for the treatment of acute esophageal food impaction. |
| Clinical Use | Several clinical trials have been reported regarding theuse of VIP or its analog for asthma and sarcoidosis. In anopen clinical Phase II study, patients with histologicallyproven sarcoidosis and active disease were treated withnebulized VIP. VIP inhalation was safe and well tolerated, and significantly reduced the production of tumornecrosis factor-α by cells isolated from the bronchoalveolar lavage fluids of these patients. |
| storage | Store at -20°C |
| Description | Vasoactive Intestinal Peptide Synthetic is a single, non-glycosylated polypeptide chain containing 28 amino acids, having a molecular mass of 3325 Dalton and a Molecular formula of C147H238N44O42S . |
