【摘要】 目的 :探讨蛋氨酸 /缬氨酸缺乏对肿瘤生长的影响及其作用机制。方法 :建立SD大鼠Walker 2 5 6癌肉瘤空肠喂饲模型 ,分A、B、C、D 4组 ,分别以平衡氨基酸、去蛋氨酸、平衡氨基酸、去缬氨酸空肠喂饲 6d ,注入3H 蛋氨酸/缬氨酸 740kBq 0 .5 ,1,2 ,4h后分别测定肿瘤组织核酸及蛋白质水解产物的3H掺入率 ;检测移植瘤重、抑瘤率。结果 :A、B组瘤重 (g)分别为 (3.5 3± 0 .2 0 )及 (2 .30± 0 .2 7) (P <0 .0 1) ,C、D组瘤重 (g)分别为 (3 .6 4± 0 .5 0 )及 (2 .6 3± 0 .37) (P <0 .0 1)。B、D组抑瘤率分别为 32 %及 2 8%。B、D组各时点蛋白质3H掺入率分别为 (0 .5 0 0± 0 .0 2 0 ) %～(3.6 70± 0 .110 ) %及 (1.887± 0 .0 2 0 ) %～ (3 .813± 0 .0 76 ) % ,分别低于A、C组 ;B组RNA、DNA的3H掺入率分别为(0 .2 73± 0 .0 75 ) %及 (0 .2 31± 0 .0 5 2 ) % ,低于A组。结论 :去蛋氨酸 /缬氨酸空肠喂饲荷瘤大鼠可抑制肿瘤蛋白质的合成 ,缺乏蛋氨酸还可影响核酸代谢 ,从而抑制肿瘤生长更多还原

【Abstract】 Abstract: To investigate the effect of methionine/valine depleted enteral nutrition on the growth of tumor in tumor bearing (TB) rats and its mechanism. Methods: SD rats were underwent catheterization of jejunostomy, a suspension of Walker 256 sarcocarcinoma cells was subcutancously inoculated. TB rats were randomly divided into 4 groups: Group A,B,C and D.TB rats had received jejunostomy feedings supplemented with balanced amino acid, methionine/valine depleted for 6 days before injection of 740 kBq 3 H methionine/valine. We assessed the weights and the inhibitory rates of tumors and 3 H incorporation rates activity into RNA,DNA and proteins in tumor tissue. Results: The average tumor weights in Group B and D were smaller than in Group A and C respectively. Incorporation rates of 3 H into proteins in group B,D were (0.500±0.020)%～(3.670±0.110)% and (1.887±0.020)% ～(3.813±0.076)%,lower than in control group. Incorporation of 3 H into RNA,DNA in Group B was (0.273±0.075)% and (0.231±0.052)% respectively, lower in group A (P<0.01). Conclusions: Protein synthesis is inhibited by methionine/valine starvation in TB rats and nucleic acids synthesis is reduced after methionine depletion. This is the main mechanism of inhibiting the growth of tumor.更多还原