Why does VIPoma cause hyperglycemia?
The profound glycogenolytic effects of VIP on the liver lead to diminished glucose intake by tissues and consequent hyperglycemia (18). Additional signs of VIPoma include skin rash, bloating, nausea, vomiting, lethargy and an involuntary decrease in weight (19).
What causes high vasoactive intestinal polypeptide?
A very high level is usually caused by a VIPoma . This is an extremely rare tumor that releases VIP. VIP is a substance found in cells throughout the body. The highest levels are normally found in cells in the nervous system and gut.
Can neuroendocrine tumors cause diabetes?
Depending on the hormones produced by the tumor, pancreatic neuroendocrine tumors can cause a variety of symptoms, including: diabetes. hypoglycemia (low blood sugar)
Why does VIPoma cause metabolic acidosis?
Hypokalemia and hyperchloremic metabolic acidosis occur due to a large amount of GI loss and bicarbonate wasting. Hypochlorhydria occurs secondary to the direct gastric acid inhibitory effect of VIP.
What does VIP do to your body?
VIP has an effect on several tissues: In the digestive system, VIP seems to induce smooth muscle relaxation (lower esophageal sphincter, stomach, gallbladder), stimulate secretion of water into pancreatic juice and bile, and cause inhibition of gastric acid secretion and absorption from the intestinal lumen.
Is VIPoma treatable?
Initial treatment of VIPomas is directed toward correcting volume and electrolyte abnormalities. Octreotide acetate controls diarrhea in up to 90% of patients with VIPomas. Glucocorticoids reduce symptoms in 50%. Systemic chemotherapy may be needed in cases of unresectable or progressive disease.
Why do neuroendocrine tumors cause diarrhea?
Excess serotonin binds to 5-hydroxytryptamine receptors in the gut to increase motility and fluid/electrolyte secretion into the gut lumen, resulting in carcinoid syndrome diarrhea (CSD).
Why is Verner Morrison syndrome associated with watery diarrhea?
This syndrome of watery diarrhea associated with hypokalemia and achlorhydria was first described by Verner and Morrison, in 1958, and has been assumed to be due to hypersecretion of VIP. In children, as well as in adult patients, the most likely explanation for persistent secretory diarrhea may be an occult VIPoma.
