VIP is a 28-amino acid neuropeptide studied in preclinical neuroscience research for its role in VPAC receptor signaling and neuroimmune pathway analysis.
Vasoactive Intestinal Peptide (VIP) is a 28-amino acid neuropeptide first isolated from porcine intestinal tissue. It belongs to the secretin/glucagon superfamily of peptides, a group of structurally related signaling molecules that also includes pituitary adenylate cyclase-activating polypeptide (PACAP), secretin, glucagon, and growth hormone-releasing hormone. VIP is widely distributed throughout the central and peripheral nervous systems and is studied in preclinical neuroscience and neuroimmune research.
VIP signals primarily through two class B G protein-coupled receptors, VPAC1 and VPAC2. Both receptors bind VIP and PACAP with similar affinity and couple predominantly to Gs proteins, leading to adenylate cyclase activation and increased intracellular cAMP in cultured cell models. VPAC1 and VPAC2 differ in their tissue distribution and expression patterns, and researchers have used selective agonists, antagonists, and receptor knockout models to characterize the distinct signaling roles of each receptor subtype. A third receptor, PAC1, binds PACAP with substantially higher affinity than VIP and is frequently used as a comparator in receptor selectivity studies.
In neuroscience research, VIP is studied as a neurotransmitter and neuromodulator. Preclinical work has examined its expression in cortical interneurons, its role in circadian signaling within the suprachiasmatic nucleus, and its effects on neuronal survival in cultured neural cell models. Downstream signaling cascades, including protein kinase A activation and CREB phosphorylation, have been characterized in controlled in vitro systems. Because VIP is rapidly degraded by peptidases in biological matrices, researchers have also developed truncated and stabilized analogues to study structure-activity relationships and receptor selectivity in laboratory assays.
VIP is also a subject of interest in neuroimmune research, where it is studied as a signaling molecule linking the nervous and immune systems. In cultured immune cell models, VPAC receptor activation has been associated with modulation of pro-inflammatory cytokine production, altered macrophage activation states, and effects on T-cell differentiation. These findings have made VIP a frequently referenced compound in preclinical studies examining how neuropeptides influence immune regulation in controlled laboratory models.
For in-vitro research use only. Not for human or veterinary use.