Analysis of Exhaled Volatile Compounds Following Acute Superior Mesenteric Artery Occlusion in a Pilot Rat Study

Abstract

Background Prompt diagnosis and treatment of acute mesenteric ischemia (AMI) requires a high index of suspicion for timely management. Poor clinical outcomes and delays in surgical treatment are demonstrated even in modern clinical series. Recognition of exhaled volatile organic compounds (VOC’s) specific to AMI may facilitate early detection and diagnosis and improve patient outcomes. Study Design Adult Wistar Rats (n=5) were intubated and anesthetized and control tracheostomy breath samples were collected using Tedlar gas sample bags. Intestinal ischemia was induced by placing an occlusive clip across the superior mesenteric artery and breath samples were collected following one hour of intestinal ischemia and following 15 minutes of intestinal reperfusion. Gas chromatography was used to identify and measure levels the VOC’s obtained and measured retention indices were compared with known values in the Kovats Retention Index. Results Multiple retention indices (n=41)) were noted on gas chromatography representing a variety of VOC’s detected. Z,Z,-farnesol (C15H26O), an isoprenoid, was the only compound detected which was undetectable during the control phase (median=0 Cts/sec, range=0) but significantly elevated during the ischemic and reperfusion phases(median=34 Cts/sec, range=25–37) and (median=148 Cts/sec. range=42–246), respectively. Three other isoprenoid compounds: E,E-alpha-farnesene, germacrene-A, and Z,Z-4,6,8-megastigmatriene were also detected in all five animals, but their levels did not differ significantly between control, ischemic and reperfusion phases. Conclusions This pilot study demonstrates the feasibility of analyzing exhaled VOC’s using a novel rat model for acute mesenteric ischemia. These findings may be useful for the development and identification of similar assays for the rapid diagnosis of acute mesenteric ischemia.

Oregano Essential Oils Promote Rumen Digestive Ability by Modulating Epithelial Development and Microbiota Composition in Beef Cattle

“…They are the main component in plants essential oils and have a broad spectrum in antimicrobial activity ( 62 ). It was reported that farnesene play a significant role during oxidative injury of eukaryotic cells ( 63 ). Sorbic acid, a food preservative and feed additive ( 64 ), could inhibit the dehydrogenase system of bacteria preventing their reproduction ( 65 ).…”

Functional testing in the diagnosis of chronic mesenteric ischemia

“…There are two animal studies to VOC detection of the changes in metabolic activity following ischemia. The first used an occlusive model (SMA occlusion) and detected various VOC's during ischemia (71). A second study studied the effects of hypovolemic shock in VOC patterns in rats and detected different molecules in early ischemia, reperfusion and during recovery (72).…”

Diagnostic potential of plasma biomarkers and exhaled volatile organic compounds in predicting the different stages of acute mesenteric ischaemia: protocol for a multicentre prospective observational study (TACTIC study)

“…The analysis of VOCs in exhaled air is a non-invasive technique that has already been demonstrated to differentiate between multiple clinical conditions and healthy subjects, including inflammatory bowel disease and non-alcoholic steatohepatitis 31. In 2011, a pilot study on the analysis of VOCs in rats following acute superior mesenteric artery (SMA) occlusion identified a small cluster of VOCs that increase during ischaemic bowel injury 32. Other studies have explored the possibility of monitoring exhaled methane (CH4) concentrations in order to detect SMA malperfusion 33.…”