Vasoactive intestinal polypeptide and gastrin-releasing peptide attenuate hepatic microvasculatory disturbances following intestinal ischemia and reperfusion

Abstract

Background/aims: In addition to the primarily affected small bowel, intestinal ischemia and reperfusion (IIR) also leads to a marked decrease in hepatic microcirculation. The aim was to determine the potentially protective effect of the vasoactive hormones vasoactive intestinal polypeptide (VIP) and gastrin-releasing peptide (GRP) on hepatic microcirculation following IIR.

Methods: Using a rat model, three animal groups were subjected to 40 min of intestinal ischemia, two of which were infused with either VIP or GRP (n = 12 each). Following reperfusion, hepatic intravital microscopy was performed. Portal venous perfusion, activities of serum glutamate pyruvate transaminase and alkaline phosphatase, mucosal injury in the small intestine and the expression of antioxidant enzymes glutathione peroxidase, copper-zinc-superoxide dismutase (Cu-Zn-SOD), glutathione reductase and catalase (CAT) in the liver were investigated.

Results: Infusion of either VIP or GRP improved hepatic microcirculation and bile flow when compared with the untreated IIR group. VIP and GRP increased portal venous blood flow during reperfusion. VIP reduced the extent of mucosal damage resulting from IIR. GRP caused a decrease in expression of CAT and Cu-Zn-SOD, whereas VIP simply reduced CAT expression.

Conclusion: This study indicates that vasoactive hormones may attenuate intestinal and hepatic injuries and circulatory disturbances following IIR.