Vasoactive intestinal peptide

Vasoactive intestinal peptide, a neuropeptide that is produced by lymphoid as well as neural cells, exerts a wide spectrum of immunological functions, controlling the homeostasis of the immune system through different receptors expressed in various immunocompetent cells.

 It is present in the peripheral and the central nervous systems where it functions as a nonadrenergic, noncholinergic neurotransmitter or neuromodulator. Significant concentrations of VIP are present in the gastrointestinal tract, heart, lungs, thyroid, kidney, urinary bladder, genital organs and the brain. The polypeptide derived its name because of its vasodilating action, which modifies the intestinal blood flow.

Vasoactive intestinal peptide was first classified as an intestinal hormone because it was isolated from the digestive tract and plays a role in electrolyte secretion in the intestinal tract, but it was subsequently found to be extensively distributed as a neurotransmitter in tissues.
Vasoactive intestinal peptide