Hypoxia Upregulates Neurokinin-1 Receptor (NK-1R) Signaling in Rat Peritoneal Mesothelial Cells (RPMCs): A Key Early Event in Intraabdominal Adhesion Formation

Abstract

Background/aim: We have reported that eating behavior differed in rats that underwent gastric bypass, sleeve gastrectomy, and/or duodenal switch procedures. Ileum transposition has been recently suggested as a metabolic surgery. The aim of the present study was to examine the eating behavior in rats that underwent ileum transposition (IT) and sleeve gastrectomy (SG). Methods: Male rats were subjected to laparotomy or IT, and 6 weeks later both groups underwent SG. Body weight was recorded weekly. Calorie intake, body composition, eating behavior, energy expenditure and fecal energy density were measured by comprehensive laboratory animal monitoring system, dual x-ray absorptiometry, and bomb calorimeter before and after surgery. Results: Body weight was lower in rats undergoing IT than those subjected to laparotomy (at 1 week, p 0.05) postoperatively. Fat compartment was reduced at 2 weeks after IT compared to laparotomy (p=0.02). After SG, body weight was reduced in both groups but more so in IT-rats (pre-operation 466±14 g vs. post-operation 378±21 g, p<0.01), which was due to reduced fat compartment. Satiety ratio was higher during daytime than nighttime regardless of surgery procedures. At both 2nd and 6th week after IT, satiety ratio was reduced during daytime but not nighttime. Calorie intake per 24 h per rat as well as per 100 g body weight was increased, which was on account of increases in number of meals, meal size, and meal duration, particularly during daytime. Rate of eating was unchanged neither during daytime nor nighttime. Energy expenditure (kcal/h/100 g body weight) was unchanged. The fecal energy density was unchanged. In laparotomy rats following SG, calorie intake relative to body weight was increased due to an increased appetite during daytime 2 weeks after SG. In IT-rats following SG, however, satiety ratio, calorie intake and energy expenditure were unchanged neither during daytime nor nighttime, but eating behavior was altered as characterized by reduced rate of eating during both daytime and nighttime, reduced meal size during nighttime, and increased meal duration during both daytime and nighttime. Conclusion: After IT procedure, satiety ratio was reduced and calorie intake increased, but these changes disappeared after additional SG. Instead, the altered eating behavior took place as manifested by eating slowly with small meal size, which may have the metabolic benefits.