Relationship of Adropin Level and Inducible Nitric Oxide Synthase with the Phases of Intestinal Ischemia-Reperfusion in Rats

Abstract
Background: Adropin is a peptide hormone that plays an important role in energy homeostasis and endothelial functions. Nitric oxide is a potent vasodilator synthesized in the vascular endothelium from the Nitric Oxide Synthase enzyme (NOS). There are controversial studies about the role of NOS and its isoforms the endothelial (eNOS) and the inducible (iNOS) forms in Ischemia-Reperfusion (IR) injury. It was found that adropin influences gene expression of eNOS and enhances endothelial cell function. However, few researchers have studied the link between adropin and iNOS activity during different phases of IR-injury.
Aim of the Study: To estimate the plasma level of adropin, and iNOS activity and to study the relationship of both of them and their role during different phases of intestinal IR-injury in rats.
Material and Methods: A total of 20 rats were used in this study (200-220g). Rats were divided into two groups (10 rats/each); group I (sham-operated group) and group II which exposed to laparotomy and occlusion of the superior mesenteric artery for 30min the reperfusion for 60min. Serial blood samples were taken via an inserted carotid catheter at 0, 30, and 90min. Plasma levels of adropin and iNOS were measured by ELISA kits according to the manufacturer protocols. The contents of the intestinal lumen were centrifuged and examined for detection of hemoglobin and albumin concentrations. ANOVA with a post hoc test, independent sample t-test, and Person correlation were used for statistical analyses.
Results: Plasma adropin level and iNOS activity are significantly increased during ischemic and reperfusion phases of intestinal IR-injury when compared to the pre-ischemic phase of group II or when compared to the sham-operated group. Adropin was significantly correlated with iNOS during all phases. Moreover, unlike adropin, the iNOS level was correlated with the severity of the intestinal bleeding.
Conclusion: Plasma adropin level is positively correlated with iNOS activity during different phases of intestinal IR-injury in rats, and this may provide new markers for diagnosis of IR-injury during intestinal surgeries.