de-Mello M A, Luciano E
Departamento de Educação Física, Universidade Estadual Paulista, Rio Claro, Brasil.
Braz J Med Biol Res. 1995 Apr;28(4):467-70.
Protein-calorie malnutrition produces glucose intolerance and reduced insulin release in response to glucose. Rats adapted to low- or high-protein diets show an increased resistance to the diabetogenic action of a single dose of streptozotocin or alloxan. To determine the effects of dietary protein level on pancreatic function, we measured serum glucose levels under basal conditions and during the oral glucose tolerance test (GTT) performed before and after a single dose of alloxan administered to rats fed a 25% or a 6% protein diet for a period of 8 weeks. The incidence of mild hyperglycemia (serum glucose > 250 mg/dl) was greater among the rats fed the 25% protein diet (81%) than among those fed the 6% protein diet (42%). During the GTT performed before alloxan administration the serum glucose levels of the rats fed the 6% protein diet were not found to be significantly different from those of rats fed the 25% protein diet. During the GTT performed after alloxan injection all rats showed intolerance to the substrate (serum glucose > 160 mg/dl 120 min after glucose administration) regardless of whether basal serum glucose was normal or high. In summary, alloxan was less effective in producing basal hyperglycemia in the rats fed the 6% protein diet than in those fed the 25% protein diet but caused glucose intolerance during the oral GTT in both groups. Thus, it seems that feeding a 6% protein diet to rats offers only partial protection against the toxic effects of alloxan.
蛋白质 - 热量营养不良会导致葡萄糖耐量降低，并减少对葡萄糖的胰岛素释放。适应低蛋白或高蛋白饮食的大鼠对单剂量链脲佐菌素或四氧嘧啶的致糖尿病作用表现出更高的抵抗力。为了确定饮食蛋白质水平对胰腺功能的影响，我们在基础条件下以及对喂食25%或6%蛋白质饮食8周的大鼠单次注射四氧嘧啶前后进行口服葡萄糖耐量试验（GTT）期间测量了血清葡萄糖水平。喂食25%蛋白质饮食的大鼠中轻度高血糖（血清葡萄糖>250mg/dl）的发生率（81%）高于喂食6%蛋白质饮食的大鼠（42%）。在注射四氧嘧啶之前进行的GTT期间，发现喂食6%蛋白质饮食的大鼠的血清葡萄糖水平与喂食25%蛋白质饮食的大鼠的血清葡萄糖水平没有显著差异。在注射四氧嘧啶后进行的GTT期间，所有大鼠无论基础血清葡萄糖是正常还是高，均表现出对底物不耐受（葡萄糖给药后120分钟血清葡萄糖>160mg/dl）。总之，四氧嘧啶在喂食6%蛋白质饮食的大鼠中产生基础高血糖的效果不如在喂食25%蛋白质饮食的大鼠中，但在两组的口服GTT期间均导致葡萄糖不耐受。因此，给大鼠喂食6%蛋白质饮食似乎只能部分保护其免受四氧嘧啶的毒性作用。
