谷氨酰胺和精氨酸联合应用对化疗后大鼠肠屏障的保护作用

目的 观察谷氨酰胺(Gln)和精氨酸(Arg)联合应用对腹腔注射氟尿嘧啶(5-FU)化疗后大鼠肠屏障的保护作用.方法 将40只接受5-FU化疗的健康雄性SD大鼠随机分为单纯肠内营养组、Gln组(肠内营养+Gln)、Arg组(肠内营养+Arg)和Arg+Gln组(肠内营养+Arg+Gln)4组,每组10只.在化疗前后测定各组大鼠体重、尿乳果糖/甘露醇比值(L/M),并在第8天测定门静脉血内毒素,进行门静脉血和淋巴结培养并测定回肠绒毛高度和回、结肠肠壁厚度.结果 除单纯肠内营养组外,其余各组大鼠体重均明显增加(P<0.05);Arg+Gln组体重增加幅度明显低于Gln组(P=0.002),与Arg组差异无统计学意义(P>0.05).化疗后各组L/M值均明显增加(P<0.05);单纯肠内营养组的增加幅度明显高于其他各组(P=0.000),其余各组间差异无统计学意义(P>0.05).单纯肠内营养组的血内毒素水平明显高于其他各组(P=0.000);Gln组明显低于Arg组(P=0.035);Arg+Gln组明显高于Gln组(P=0.000),但与Arg组差异无统计学意义(P=0.109).单纯肠内营养组的回肠绒毛高度和回肠壁厚度明显低于其他各组(P=0.000),结肠壁厚度明显低于Arg组和Arg+Gln组(P=0.000),与Gln组差异无统计学意义(P=0.058);Gln组的回肠壁厚度(P=0.040)和结肠壁厚度(P=0.010)明显高于Arg组,回肠绒毛高度与Arg组差异无统计学意义(P=0.286);Gln组回肠壁厚度明显高于Arg+Gln组(P=0.028),结肠壁厚度(P=0.462)和回肠绒毛高度(P=0.190)与Arg+Gln组差异无统计学意义;Arg组结肠壁厚度明显低于Arg+Gln组(P=0.010),回肠绒毛高度(P=0.803)及回肠壁厚度(P=0.059)与Ag+Gln组差异无统计学意义.各组间门静脉血和淋巴结细菌培养结果差异无统计学意义(P>0.05).结论 Arg、Gln对腹腔注射5-FU化疗后大鼠肠屏障功能具有保 护作用,Gln的保护作用略优于Arg,两者没有明显的协同作用.

Protective effect of the combination of glutamine and arginine on intestinal barrier function in rats receiving fluorouracil chemotherapy

Objective To investigate the protective effect of the combination of glutamine (Gln) and ar-ginine (Arg) on intestinal barrier function in rats receiving fluorouracil (5-FU) chemotherapy.Methods Totally 40 male SD rats receiving 5-FU chemotherapy were equally randomized into four groups:enteral nutrition group,Gln group (enteral nutrition+Gln),Arg group (enteral nutrition+Arg),and Arg+Gln group (enteral nutri-tion+Arg+Gln).Observe the changes post chemotherapy such as the changes of body weight and urine lactulose/mannitol ratio before and after chemotherapy were recorded.On the 8 th post-therapy day,the blood endotoxin level in portal vein was measured,and lymph nodes and blood in portal vein were taken for bacterial culture;colon and jejunum specimens were also taken to measure the height of jejunum villus and the thickness of colon and jejunum.Results Body weights of Gln group,Arg group,and Arg+Gln group significantly increased after chemotherapy (P<0.05).The change of body weight was significantly lower in Arg+Gln group than in Gln group (P=0.002),while no such difference was found when compared with that in Arg group (P>0.05).Lactulose/manni-tol ratio in each group significantly increased after chemotherapy (P<0.05),and the change of lactulose/mannitol ratio was significantly higher in the enteral nutrition group than those in other groups (P=0.000);however,no such difference was found among other groups (P>0.05).The blood endotoxin level in portal vein was signifi-cantly higher in enteral nutrition group than in other groups (P=0.000);the endotoxin level was significantly lower in Gln group than in Arg group (P=O.035) and Arg+Gln group (P=0.000);however,no such differ-ence was found between Arg group and Arg+Gln group (P=0.109).The height of jejunum villus and the thick-ness of jejunum were significantly lower in enteral nutrition group than those in the other groups (P=O.000);the thickness of colon was significantly lower in enteral nutrition group than those in Arg group and Arg+Gln group (P=0.000);however,no such difference was found when compared with Gln group (P=0.058).The thickness of colon (P=0.040) and jejunum (P=0.010) was significantly higher in Gln group than that in Arg group;but there was no significant difference in term of the height of jejunum villus (P=0.286).Compared with Arg+Gln group,the thickness of jejunum in Gln group was significantly higher,but there was no significant difference in terms of the height of jejunum villus (P=0.286) or the thickness of jejunum (P=0.190).The thickness of co-lon was significantly lower in Arg group than in Arg+Gln group (P=0.010),while no such significant difference was found in terms of the height of jejunum villus (P=0.803) or the thickness of colon (P=0.059) when com-pared with Arg+Gln group.The bacterial culture results were not significantly different among all groups.Conclu-sions The combination of Arg and Gln has protective effects on intestinal barrier in rats receiving 5-FU chemother-apy.The protective effect of Gln is superior to that of Arg.No synergistic effect exists between Arg and Gln.