vasoactive-intestinal-peptide and Mesenteric-Vascular-Occlusion

Mesenteric lymph pathway serves as the primary route by which gut injury leads to systemic inflammation and distant organ injury. The inflammation of the intestinal tract is partially mediated by vasoactive intestinal peptide (VIP). Therefore, the aim of this study was to test whether exogenous VIP affects mesenteric lymph pathway during early intestinal ischemia-reperfusion (IIR) injury. Rats were randomized into control, control+VIP, IIR and IIR+VIP groups. The observation of mesenteric lymph flow was carried out by cannulation of mesenteric lymphatics. The distribution of in vivo lymphocyte trafficking was performed by (51)Cr labeled lymphocytes and was measured by γ-counter. Endotoxin concentration was assayed using the limulus test kit and TNF-α level was detected by ELISA. When IIR injury treated with VIP, the volumes of lymph flow increased by 80%, which caused the number of lymphocytes exiting in mesenteric lymphatic increased by 50% while the proportion of (51)Cr-lymphocytes in Peyer's patches, intestinal effector tissues, mesenteric nodes, large intestine, stomach decreased by 58%, 51%, 58%, 63%, 64% respectively at the 6th h after reperfusion following intestinal ischemia. Meanwhile, endotoxin and TNF-α levels in intestinal lymph decreased by 51% and 83%. These results suggest that exogenous VIP ameliorates IIR induced splanchnic organ damage via inhibition of toxic mediators reaching systemic circulation and reinforcement of the effective immune responses in gut-associated lymphoid tissues (GALT).

Topics: Animals; Cell Movement; Drug Evaluation, Preclinical; Endotoxins; Ileum; Lymph; Lymphatic Vessels; Lymphocyte Count; Lymphocytes; Male; Mesenteric Arteries; Mesenteric Vascular Occlusion; Rats; Rats, Wistar; Reperfusion Injury; Tumor Necrosis Factor-alpha; Vasoactive Intestinal Peptide

The effect of mesenteric ischaemia on the levels of neurotensin, vaso-active intestinal polypeptide and gastrin in portal venous blood and in the peripheral circulation was studied in two groups of 7 and 6 baboons (Papio ursinus). In peripheral blood a decreasing trend in levels of neurotensin was observed, while vaso-active intestinal polypeptide and gastrin levels were unchanged. There was a similar trend in neurotensin levels in portal venous blood, together with an increasing trend in levels of vaso-active intestinal polypeptide. Gastrin levels were unchanged. Further investigation of these apparent trends in a large number of animals is warranted.

Topics: Animals; Gastrins; Mesenteric Vascular Occlusion; Neurotensin; Papio; Vasoactive Intestinal Peptide

Vaso-active intestinal polypeptide (VIP) and the related peptide, peptide histidine isoleucine, were infused intravenously in anaesthetized sheep. The VIP doses were designed to reproduce plasma concentrations seen after mesenteric ischaemia. The vasodilator action of VIP varied between different segments of the circulation and these differences in sensitivity were observed for both the degree and duration of the vaso-active action. A sustained vasodilation was detected in the coeliac artery and portal vein vascular beds during a 30-min VIP infusion. VIP is likely to be a contributory factor involved in the development of circulatory collapse during reperfusion after experimental mesenteric ischaemia.

Topics: Animals; Blood Circulation; Celiac Artery; Hemodynamics; Histidine; Infusions, Intravenous; Isoleucine; Mesenteric Arteries; Mesenteric Vascular Occlusion; Methionine; Sheep; Splanchnic Circulation; Vascular Resistance; Vasoactive Intestinal Peptide; Vasodilation