From the Guidelines
VIP, or Vasoactive Intestinal Peptide, is a neuropeptide that acts as a potent vasodilator, relaxing blood vessels and increasing blood flow to various organs, particularly in the gastrointestinal tract, and its dysregulation has been implicated in several disorders, including inflammatory bowel disease, asthma, and certain neurological conditions. The functions of VIP include stimulating secretion of water and electrolytes in the intestines, helping maintain proper digestive function, inhibiting gastric acid secretion, reducing smooth muscle contraction in the intestines and airways, and having anti-inflammatory properties 1. In the nervous system, VIP functions as a neurotransmitter and neuromodulator, playing roles in circadian rhythm regulation, memory formation, and neuroprotection 1. VIP's diverse actions stem from its ability to bind to specific receptors (VPAC1 and VPAC2) on target cells, activating adenylyl cyclase and increasing intracellular cAMP levels, which triggers various cellular responses 1. Some key points about VIP include:
- It is involved in the pathophysiology of dumping syndrome, particularly early dumping syndrome, where it contributes to the increased release of multiple GI hormones, including vasoactive agents, incretins, and glucose modulators 1
- Its dysregulation can lead to various disorders, and treatment with somatostatin analogues, such as octreotide or lanreotide, can help control symptoms in patients with carcinoid syndrome or VIPomas 1. Overall, VIP plays a crucial role in maintaining various physiological functions, and its dysregulation can have significant consequences for morbidity, mortality, and quality of life.
From the Research
Physiological Effects of VIP
- Vasoactive intestinal peptide (VIP) has multiple physiological effects on development, growth, and the control of neuronal, epithelial, and endocrine cell functions 2
- VIP regulates ion secretion, nutrient absorption, gut motility, glycemic control, carcinogenesis, immune responses, and circadian rhythms 2
- VIP has pleiotropic effects as a neurotransmitter, immune regulator, vasodilator, and secretagogue 3
Pathological Effects of VIP
- Excessive VIP secretion can produce a clinical syndrome characterized by refractory watery diarrhea, hypokalemia, and metabolic acidosis 4
- VIPomas, tumors that secrete VIP, can cause severe symptoms and have a high malignancy rate 4, 5
- VIP-secreting tumors can also cause flushing, watery diarrhea, and high sensitivity to octreotide 5
Therapeutic Applications of VIP
- VIP has potential therapeutic applications in diabetes, autoimmune diseases, and cancer 2
- Octreotide, a somatostatin analogue, has been shown to be effective in treating VIPomas and other conditions associated with excessive peptide secretion 6
- VIP receptor signaling has been implicated in inflammatory and autoimmune disorders, and VIP may have future therapeutic directions in these areas 3