Effect of N -Acetylserotonin on Intestinal Recovery Following Intestinal Ischemia-Reperfusion Injury in a Rat

Objective N-acetylserotonin (NAS) is a naturally occurring chemical intermediate in the biosynthesis of melatonin. Extensive studies in various experimental models have established that treatment with NAS significantly protects heart and kidney injury from ischemia-reperfusion (IR). The purpose of the present study was to examine the effect of NAS on intestinal recovery and enterocyte turnover after intestinal IR injury in rats. Methods Male Sprague-Dawley rats were divided into four experimental groups: (1) Sham rats underwent laparotomy, (2) sham-NAS rats underwent laparotomy and were treated with intraperitoneal (IP) NAS (20 mg/kg); (3) IR rats underwent occlusion of both superior mesenteric artery and portal vein for 30 minutes, followed by 48 hours of reperfusion, and (4) IR-NAS rats underwent IR and were treated with IP NAS (20 mg/kg) immediately before abdominal closure. Intestinal structural changes, Park injury score, enterocyte proliferation, and enterocyte apoptosis were determined 24 hours following IR. The expression of Bax, Bcl-2, p-ERK, and caspase-3 in the intestinal mucosa was determined using real-time polymerase chain reaction, Western blot, and immunohistochemistry. A nonparametric Kruskal-Wallis analysis of variance test was used for statistical analysis with p less than 0.05 considered statistically significant. Results Treatment with NAS resulted in a significant increase in mucosal weight in jejunum and ileum, villus height in the ileum, and crypt depth in jejunum and ileum compared with IR animals. IR-NAS rats also had a significantly proliferation rates as well as a lower apoptotic index in jejunum and ileum which was accompanied by higher Bcl-2 levels compared with IR animals. Conclusions Treatment with NAS prevents gut mucosal damage and inhibits programmed cell death following intestinal IR in a rat.