VIP (Vasoactive Intestinal Peptide): A Laboratory Research Reference

Vasoactive intestinal peptide (VIP) is a 28-amino-acid neuropeptide of the secretin/glucagon peptide family. It is studied in laboratory research for its activity at VPAC receptors and for its roles in vasodilation, smooth-muscle relaxation, and neuroimmune signalling in experimental models.

This page is a non-promotional scientific reference for researchers. It summarises the chemical identity, molecular characteristics, mechanism as described in the literature, research areas, and analytical testing of VIP. It does not provide dosing, therapeutic, or human-use guidance of any kind. VIP supplied by Bulk Aussie Peptides is for laboratory research purposes only.

What Is VIP?

Vasoactive intestinal peptide is a 28-residue neuropeptide first isolated from porcine intestinal tissue. It shares sequence homology with other members of the secretin/glucagon family, including secretin, glucagon, and pituitary adenylate cyclase-activating polypeptide (PACAP). VIP is found in both the central nervous system and peripheral tissues, where it is produced as part of a larger precursor protein.

For background on how synthetic research peptides are produced and verified, see the synthetic peptides research guide.

Molecular Characteristics

• Classification: a 28-amino-acid neuropeptide of the secretin/glucagon family.
• Sequence: a 28-residue peptide sharing homology with secretin, glucagon, and PACAP.
• Molecular weight: near 3,326 Da; the measured value on a Certificate of Analysis should be compared against the theoretical mass.
• Physical form: supplied as a lyophilised (freeze-dried) powder, the standard presentation for research peptides.

How VIP Works

VIP acts as an agonist at VPAC1 and VPAC2 receptors, G-protein-coupled receptors coupled to cyclic AMP signalling. In laboratory models, receptor activation is associated with vasodilation, relaxation of airway and gastrointestinal smooth muscle, and modulation of immune-cell activity. These diverse actions make the VIP/VPAC system a focus of study across vascular, pulmonary, and neuroimmune research.

These observations describe receptor pharmacology in model systems and do not constitute a therapeutic use.

Areas of Scientific Research

• VPAC receptor pharmacology: characterisation of receptor binding and signalling.
• Vascular and smooth-muscle biology: studies of vasodilation and muscle relaxation in experimental models.
• Neuroimmunology: investigation of VIP in neuroimmune signalling pathways.

These investigations are conducted in vitro or in approved animal research models under institutional oversight. They do not translate to approved human use.

Analytical Testing

• HPLC for purity assessment, reported as a percentage of total peak area.
• Mass spectrometry for identity confirmation against the theoretical molecular mass.

Guidance on reading the resulting documents is available in the article on how to read a peptide Certificate of Analysis.

Storage and Handling

In a laboratory context, lyophilised VIP is typically stored in a freezer, protected from light and moisture, and handled according to the product-specific documentation. General guidance is covered in the peptide storage and stability reference.

Frequently Asked Questions

• What is VIP? VIP is a 28-amino-acid neuropeptide of the secretin/glucagon family.
• What receptors does VIP target? It acts as an agonist at VPAC1 and VPAC2 receptors.
• What is VIP related to? It shares sequence homology with secretin, glucagon, and PACAP.
• What is VIP studied for? It is investigated in laboratory models for vasodilation, smooth-muscle relaxation, and neuroimmune signalling.
• How is VIP purity tested? By HPLC, with identity confirmed by mass spectrometry.

References

• Said, S. I., & Mutt, V. (1970). Polypeptide with broad biological activity: Isolation from small intestine. Science, 169(3951), 1217–1218. PubMed 5450698

Related Research Resources

• Synthetic Peptides: Research Guide — how research peptides are produced and verified.
• Reading a Peptide Certificate of Analysis — interpreting purity and identity data.