Bell R C, Sakanashi T M, Keen C L, Finegood D T
Department of Medicine, University of Alberta, Edmonton, Canada.
Biol Trace Elem Res. 1998 Feb;61(2):137-49. doi: 10.1007/BF02784026.
Trace element status is known to be altered in the diabetic state, although the factors affecting trace element homeostasis in this condition are not well understood. The authors examined the effects of a high fructose diet (40% wt:wt) vs a control diet on the copper (Cu), zinc (Zn), and iron (Fe) concentrations in the kidney, plasma, and red blood cells of islet transplanted (TX) and sham-operated (SHAM) rats. Male, Wistar Furth rats made diabetic by streptozotocin injection (55 mg/kg, iv) were given an intraportal islet transplant (1000 islets); control animals were sham-injected, sham-operated (SHAM). Rats within TX and SHAM groups were assigned to either a high fructose diet (40% fructose, 25% cornstarch, FR) or a purified control diet (33% cornstarch, 33% dextrose, CNTL) containing identical amounts of mineral mixture for a period of 6 wk. Kidney Cu concentration was significantly elevated among hyperglycemic TX-CNTL rats (224+/-25 nmol/g wet wt), but was markedly reduced in hyperglycemic TX-FR rats (109+/-14 nmol/g) relative to normoglycemic controls. This occurred in spite of similar levels of glucose, insulin (fed and fasted), insulin secretory capacity, body weight, and food intake in the TX-CNTL and TX-FR groups. Among the subgroup of rats with normal glucose levels post-TX, kidney Cu levels normalized and were unaffected by dietary treatment (normoglycemic TX-CNTL = 60+/-5 nmol/g; normoglycemic TX-FR = 40+/-2 nmol/g). Kidney Cu concentrations also were unaffected by fructose feeding in SHAM animals (CNTL, 60+/-4 nmol/g and FR, 51+/-5 nmol/g). Kidney Zn and Fe concentrations were similar among the treatment groups. Plasma and red blood cell (RBC) Cu, Zn, and Fe concentrations were also similar among the groups. Since fructose feeding led to a substantial reduction of kidney Cu concentrations in the presence of hyperglycemia, the authors suggest that this model can be useful in examining effects of altered kidney Cu accumulation in the diabetic animal.
已知糖尿病状态下微量元素状况会发生改变，尽管影响该状态下微量元素稳态的因素尚未完全明确。作者研究了高果糖饮食（40%重量比）与对照饮食对胰岛移植（TX）和假手术（SHAM）大鼠肾脏、血浆及红细胞中铜（Cu）、锌（Zn）和铁（Fe）浓度的影响。通过链脲佐菌素注射（55mg/kg，静脉注射）使雄性Wistar Furth大鼠患糖尿病，然后进行门静脉内胰岛移植（1000个胰岛）；对照动物进行假注射、假手术（SHAM）。TX组和SHAM组的大鼠被分配至高果糖饮食（40%果糖，25%玉米淀粉，FR）或含有等量矿物质混合物的纯化对照饮食（33%玉米淀粉，33%葡萄糖，CNTL），为期6周。与血糖正常的对照组相比，高血糖TX-CNTL大鼠的肾脏铜浓度显著升高（224±25nmol/g湿重），但高血糖TX-FR大鼠的肾脏铜浓度显著降低（109±14nmol/g）。尽管TX-CNTL组和TX-FR组的血糖、胰岛素（喂食和禁食状态下）、胰岛素分泌能力、体重及食物摄入量水平相似，但仍出现了这种情况。在TX后血糖水平正常的大鼠亚组中，肾脏铜水平恢复正常，且不受饮食处理影响（血糖正常的TX-CNTL = 60±5nmol/g；血糖正常的TX-FR = 40±2nmol/g）。SHAM动物的果糖喂养对肾脏铜浓度也无影响（CNTL组，60±4nmol/g；FR组，51±5nmol/g）。各治疗组间肾脏锌和铁浓度相似。各组间血浆及红细胞（RBC）中的铜、锌和铁浓度也相似。由于在高血糖情况下果糖喂养导致肾脏铜浓度大幅降低，作者认为该模型可用于研究糖尿病动物肾脏铜蓄积改变的影响。
