Do Elevated Plasma Vasoactive Intestinal Polypeptide (VIP) Levels Cause Small Intestinal Motor Disturbances in Humans?

Abstract

Increased VIP plasma levels cause severe secretory diarrhea. Moreover, VIP is a major regulator of human intestinal motility. We hypothesized that VIP-mediated intestinal motility disturbances contribute to symptoms in elevated plasma VIP. Ten healthy volunteers were intubated twice with an orojejunal multilumen tube for duodenal manometry, jejunal perfusion of electrolyte and marker solution, and aspiration 10 and 40 cm more distally. All subjects randomly received intravenous infusion of saline and 300 pmol/kg x hr VIP for 5 hr. Results showed that VIP but not saline infusion induced netjejunal sodium secretion, watery diarrhea, and cardiovascular effects (P < 0.04). VIP did not alter intestinal motor activity or the mean duration of the interdigestive motility cycle or of phases I and II but nearly halved the duration of phase III (P = 0.0002). We conclude that increased plasma VIP markedly shortens human phase III activity without influencing other motility parameters. Hence, it is unlikely that VIP-mediated small intestinal motor disturbances cause symptoms in VIPOMA. Yet VIP may contribute to terminate phase III motility.

Prevalence and pathophysiology of early dumping in patients after primary Roux-en-Y gastric bypass during a mixed-meal tolerance test

“…Data of 46 patients were available for analysis: 34 women and 12 men with a median age of 47 years (39)(40)(41)(42)(43)(44)(45)(46)(47)(48)(49)(50)(51)(52)(53)(54). BMI was 46.1 kg/m 2 (42.0; 48.5) before RYGB and 31.2 kg/m 2 (28.6; 35.0) after surgery, resulting in an excess weight loss of 68.1% (54.9; 79.4) and a total weight loss of 33.1% (23.6; 37.7).…”

“…VIP is known to cause a cascade of postprandial reactions upon direct and indirect pathways: a strong vasodilator, it reverses normal intestinal absorption and causes secretory diarrhea, stimulates gastrointestinal transit, relaxes vascular and nonvascular smooth muscle cells, increases heart rate, decreases diastolic blood pressure, and causes symptoms similar to those seen in early dumping [36,38,39] . We had expected to see a higher concentration of VIP in the group high suspicion for early dumping, but we could not confirm this hypothesis in our study.…”

Vasoactive Intestinal Peptide Tumor

“…The hormone functions as a potent stimulator of adenylate cyclase, which induces the secretion of water and electrolytes by intestinal mucosa [5]. Furthermore, VIP stimulates alkaline pancreatic juice and acid secretion, lipolysis, glycogenolysis, pentagastrin secretion, and inhibits histamine release [1], and is therefore widely considered to be a major regulator of human intestinal motility [6].…”

Neuropeptide Modulators of High Mobility Group Box 1 Secretion as Potential Therapeutic Agents for Severe Sepsis

“…VIP infused into normal human volunteers has been shown to cause a range of adverse effects, including diarrhea and tachycardia. 41 Whether these side effects would occur in septic patients, or be tolerable in the context of treating a life-threatening illness, remains to be determined. Infusion of urocortin into normal human volunteers seems to be better tolerated, 42 and, therefore, this neuropeptide might be a more promising candidate for further development as an adjuvant therapeutic for severe sepsis.…”