VIP Peptide Research: VPAC Signaling and Neuroimmune Models
VIP Peptide Research: VPAC Signaling and Neuroimmune Models
A plain-English guide to vasoactive intestinal peptide, VPAC1 and VPAC2 signaling, animal inflammation models, and the limits of translation.
VIP connects neural, vascular, and immune signaling
Vasoactive intestinal peptide is a 28-amino-acid neuropeptide that signals mainly through the VPAC1 and VPAC2 G-protein-coupled receptors. These receptors commonly raise cyclic AMP inside cells.
Laboratory studies examine smooth-muscle and vascular effects alongside macrophage, dendritic-cell, and T-cell signaling. Some models report lower NF-κB activity, chemokine output, or inflammatory measures.
Those findings are model-dependent. VIP is a potent vasoactive, rapidly metabolized signaling molecule, and the cited research does not establish a general human anti-inflammatory therapy.
What researchers are trying to understand
What are VPAC1 and VPAC2?
They are the main G-protein-coupled receptors for VIP and commonly signal through cyclic AMP, with expression and effects varying by cell and tissue.
What does neuroimmune mean here?
VIP is produced in neural and other tissues while its receptors appear on immune cells. Research therefore examines communication across neural, vascular, gastrointestinal, and immune systems.
Are there direct human treatment data in this set?
No. The human endotoxin paper measured receptor expression during a controlled challenge; it did not test VIP as a treatment.
Notable studies, in plain English
The studies below are separated by model and design so that early laboratory signals are not confused with evidence from people.
VIP regulation of macrophage chemokines
- Model
- Cultured macrophages and a mouse acute-peritonitis model
- Design
- In vitro signaling experiments with animal inflammation testing
What the paper reported: VIP reduced several chemokine signals through a VPAC1 and cyclic-AMP-linked pathway and was associated with less leukocyte recruitment in mice.
Important limit: The work does not establish a human anti-inflammatory effect.
VIP in collagen-induced arthritis
- Model
- Mouse collagen-induced arthritis
- Design
- Controlled animal disease-model study
What the paper reported: Researchers reported lower experimental severity and changes in inflammatory and autoreactive immune measures.
Important limit: A mouse arthritis model is not evidence of efficacy in human rheumatoid arthritis.
VIP in TNBS-induced colitis
- Model
- Mouse chemically induced colitis
- Design
- Controlled animal disease-model study
What the paper reported: VIP altered experimental colitis severity and immune readouts.
Important limit: The study does not establish safety or efficacy for human inflammatory bowel disease.
VIP in experimental autoimmune encephalomyelitis
- Model
- Mouse EAE neuroinflammation model
- Design
- Controlled animal disease-model study
What the paper reported: VIP was associated with reduced model severity, inflammation, and antigen-specific T-cell responses.
Important limit: EAE is not a clinical multiple-sclerosis trial.
VPAC1 expression during human endotoxemia
- Model
- 20 healthy men undergoing controlled endotoxin challenge
- Design
- Controlled human challenge and receptor-expression study
What the paper reported: The study tracked changes in VPAC1 receptor expression after endotoxin exposure.
Important limit: It investigated receptor biology and did not administer VIP as a treatment.
What the evidence does—and does not—establish
Mouse models of arthritis, colitis, and neuroinflammation do not establish efficacy for the corresponding human diseases. Lower cytokine or chemokine readouts also do not, by themselves, demonstrate a clinical benefit.
Evidence about naturally produced VIP does not establish the safety or behavior of externally supplied research material. The controlled human challenge study examined receptor expression rather than VIP treatment, and the cited work provides no basis for human-use guidance.
- VIP signals mainly through VPAC1 and VPAC2 receptors.
- Cyclic AMP and immune-cell signaling are recurring mechanisms.
- Most disease-oriented evidence in this set comes from mice.
- The human challenge study measured a receptor and did not test VIP therapy.
Where to buy VIP for laboratory research in the USA
A research listing should disclose peptide sequence, molecular identity, purity method and result, lot-specific COA, physical form, and intended analytical or laboratory use. The page should distinguish VIP-28 from any related fragment or analog.
Where-to-buy VIP and USA supplier language should remain within a laboratory-procurement section. Avoid attaching those terms to disease, anti-inflammatory, vascular, dosing, or administration claims.
Searches such as “where to buy VIP,” “buy VIP USA,” and “USA peptides” should be treated as laboratory-sourcing questions. Compare U.S. research suppliers by lot traceability, identity testing, quantitative-content information, analytical methods, and stated research-use restrictions—not by implied human outcomes.
VIP research FAQ
What does VIP stand for?
VIP means vasoactive intestinal peptide, a 28-amino-acid signaling peptide found in neural, gastrointestinal, vascular, and immune contexts.
What are VPAC1 and VPAC2?
They are the main G-protein-coupled receptors through which VIP signals, often by increasing cellular cyclic AMP.
Do VIP animal studies prove a human anti-inflammatory effect?
No. They test mechanisms in specific models and require controlled human confirmation.
Was VIP tested in the cited human endotoxin study?
No. That study tracked VPAC1 receptor expression during an endotoxin challenge.
What matters when sourcing VIP for research?
Sequence identity, purity and identity methods, lot-specific documentation, physical form, and a clear research-use limitation.
Primary references
References link to the original journal record or publisher page. Inclusion is not an endorsement of a product or a clinical conclusion.
- Delgado and Ganea (2001). PMID 11441105. DOI 10.4049/jimmunol.167.2.966.
- Delgado et al. (2001). PMID 11329057. DOI 10.1038/87887.
- Abad et al. (2003). PMID 12671893. DOI 10.1053/gast.2003.50141.
- Gonzalez-Rey et al. (2006). PMID 16565493; PMCID PMC1606545. DOI 10.2353/ajpath.2006.051081.
- Hoetzenecker et al. (2013). PMID 23651810; PMCID PMC3651401. DOI 10.1186/1479-5876-11-117.