VIP (Vasoactive Intestinal Peptide)

Overview

VIP (Vasoactive Intestinal Peptide) is a 28-amino acid neuropeptide belonging to the secretin/glucagon peptide family. Originally discovered in the gut, it is now known to be expressed throughout the body with critical roles in gastrointestinal function, immune regulation, circadian rhythm control, and neuroprotection.

Mechanism of Action

VIP signals through VPAC1 and VPAC2 receptors (G-protein coupled), activating adenylyl cyclase and increasing cAMP. In the gut, it promotes smooth muscle relaxation, stimulates water and electrolyte secretion, and supports mucosal blood flow. In the immune system, it shifts macrophage polarization toward anti-inflammatory phenotypes. In the brain, it regulates circadian rhythms in the suprachiasmatic nucleus.

Research Context

VIP research spans gastroenterology, immunology, neuroscience, and pulmonology. It has been investigated in inflammatory bowel disease, CIRS (Chronic Inflammatory Response Syndrome), pulmonary hypertension, and neurodegenerative disease models.

Key Research Areas

Considerations for Researchers

VIP has a very short half-life (1-2 minutes in circulation). This necessitates either continuous infusion or frequent dosing in research protocols. Store lyophilized at -20C. Reconstitute fresh for each use.