RFRP-3对大鼠采食行为和生长性能的影响

为了探讨RFRP-3对大鼠采食行为以及生长性能的影响,选取体重相近的清洁级SD大鼠30只,随机分为3组,分别为对照组腹腔注射生理盐水200 μL/(次·只)]、RFRP-3低剂量组腹腔注射1 μg/100 μL RFRP-3,200 μL/(次·只)]和高剂量组腹腔注射10 μg/100 μL RFRP-3,200 μL/(次·只)],每组10只,雌、雄各半,每天注射2次,连续腹腔注射14 d。观察和记录大鼠的采食量、采食行为和体重变化,计算料肉比及Lee指数,分离血清并检测血脂相关指标,并对下丘脑食欲相关因子的表达水平进行检测。结果表明,与对照组相比,仅在光照环境中腹腔注射高剂量RFRP-3会导致大鼠采食量极显著(P<0.01)增加;采食行为方面主要表现为采食频率极显著(P<0.01)增高和饱腹率明显下降;生长性能方面主要表现为体重增长极显著(P<0.01)加快以及料肉比显著(P<0.05)降低;在肥胖指标中,Lee指数显著(P<0.05)增加,血清中甘油三酯和总胆固醇的含量极显著(P<0.01)升高;下丘脑NPY mRNA表达水平显著(P<0.05)上升,而POMC mRNA表达水平显著(P<0.05)下降。试验表明,腹腔注射RFRP-3可促进大鼠的采食行为并提高其生长性能,且这种生理功能的发挥可能是通过调节下丘脑食欲相关因子的变化完成的。

Effects of RFRP-3 on Feeding Behavior and Growth Performance of Rats

In order to investigate the effect of RFRP-3 on the feeding behavior and growth performance of rats,a total of 30 clean-grade SD rats with similar weight were selected and randomly assigned into the following three groups:a control group received a 200μL saline solution per rat per time by intraperitoneal injection,a low-dose RFRP-3 treatment group received the 200μL RFRP-3 solution with concentration of 1μg/100μL per rat per time by intraperitoneal injection,and a high-dose RFRP-3 treatment group received the 200μL RFRP-3 solution with concentration of 10μg/100μL per rat per time by intraperitoneal injection.There were 10 rats in each group with half male and half female.All of the experimental rats received intraperitoneal injection twice daily for consecutive 14 days.During the whole experimental period,the feed intake,feeding behavior and body weight of the experimental rats were observed and recorded;the feed to gain ratio and Lee index were calculated,the serum was isolated from the blood samples,the blood lipid related indicators were determined,and the expression level of hypothalamus appetite related factors was assessed.The results showed that compared with the control group,the intraperitoneal injection of high dose RFRP-3 resulted in an extremely significant(P<0.01)increase in feed intake in rats in light-environment,and the feeding behavior was mainly manifested in a extremely significant(P<0.01)increase in feeding frequency and an obvious decrease in satiety;in terms of growth performance,the RFRP-3 treatment groups had a very significant(P<0.01)increase in body weight and a significant(P<0.05)reduction in feed to gain ratio;for obesity indexes,the Lee index of the rats was increased significantly(P<0.05)after receiving the intraperitoneal injection of RFRP-3,and the serum contents of triglycerides and total cholesterol were also very significantly(P<0.01)increased;the expression level of NPY mRNA in the hypothalamus in RFRP-3 treatment groups was increased significantly(P<0.05),while that of POMC mRNA was decreased significantly(P<0.05).In conclusion,intraperitoneal injection of RFRP-3 can improve the feeding behavior and growth performance of rats,and this physiological function may be achieved via regulating the appetite-related factors in hypothalamus.