Yoshida S, Yamasaki K, Kaibara A, Takagi K, Noake T, Ishibashi N, Kakegawa T
First Department of Surgery, Kurume University, School of Medicine, Fukuoka, Japan.
Cancer. 1995 Oct 1;76(7):1275-82. doi: 10.1002/1097-0142(19951001)76:7<1275::aid-cncr2820760727>3.0.co;2-z.
Previous studies have shown that a methionine-lacking diet inhibited tumor growth in rats. The aim of this study was to determine how methionine free total parenteral nutrition (MTPN) can result in the inhibition of tumor growth on tumor protein metabolism in rats.
On day 0, AH109A rat ascites hepatoma cells were implanted subcutaneously into male Donryu rats (n = 68, body weight, 200-225 gm). On day 10, a catheter for total parenteral nutrition (TPN) was placed and either MTPN or standard TPN solution was given for 5 days. On day 15, 1-14C-leucine was infused continuously to measure tumor protein synthesis. Tumor proteolysis was calculated from tumor regional blood flow, using the 85Sr-microsphere injection method.
The enhanced tumor protein breakdown contributed to the inhibition of tumor growth that was found with the rats given the methionine free diet.
先前的研究表明,缺乏蛋氨酸的饮食可抑制大鼠肿瘤生长。本研究的目的是确定无蛋氨酸全胃肠外营养(MTPN)如何导致大鼠肿瘤生长受抑制以及对肿瘤蛋白质代谢的影响。
第0天,将AH109A大鼠腹水肝癌细胞皮下植入雄性东京大鼠(n = 68,体重200 - 225克)。第10天,放置用于全胃肠外营养(TPN)的导管,并给予MTPN或标准TPN溶液5天。第15天,持续输注1-¹⁴C-亮氨酸以测量肿瘤蛋白质合成。使用⁸⁵Sr-微球注射法根据肿瘤局部血流计算肿瘤蛋白水解。
1)MTPN使肿瘤重量减轻。2)MTPN不影响肿瘤蛋白质合成,可能是因为MTPN使内源性蛋氨酸生成增加(87.3±13.5微摩尔蛋氨酸/千克/小时对218.6±29.5,P < 0.01);然而,MTPN导致肿瘤蛋白水解增加(2.68±0.53微摩尔亮氨酸/克/小时对3.79±0.73,P < 0.05)。
肿瘤蛋白质分解增强导致了给予无蛋氨酸饮食的大鼠出现肿瘤生长受抑制的情况。