Martin A A, Tomas F M, Owens P C, Knowles S E, Ballard F J, Read L C
Child Health Research Institute, Adelaide Medical Center for Women and Children, South Australia.
Am J Physiol. 1991 Oct;261(4 Pt 2):F626-33. doi: 10.1152/ajprenal.1991.261.4.F626.
The efficacy of insulin-like growth factor I (IGF-I) in enhancing growth in animals with reduced renal mass was investigated in subtotally nephrectomized young male rats. Recombinant human IGF-I was administered by osmotic minipumps for 7 days at two doses, 0.9 and 2.2 mg.kg body wt-1. day-1, and the truncated analogue of IGF-I, des-(1-3)IGF-I, was given at a dose of 0.9 mg.kg body wt-1.day-1. The partial nephrectomy procedure resulted in significantly impaired renal function as evidenced by elevated serum urea and creatinine concentrations, reduced creatinine clearance, and increased average daily urine output. Carcass composition was significantly altered in animals with reduced renal mass; water content increased and fat content decreased, while protein content remained unchanged. Carcass composition was not affected by IGF treatment. Body weight gain, food utilization, and nitrogen balance during the treatment period were significantly increased in rats treated with IGF-I at both the lower and higher doses and in those treated with des-(1-3)IGF-I. The improved nitrogen balance in the des-(1-3)IGF-I group could at least partly be explained by a diminished rate of muscle protein breakdown, as indicated by the reduced urinary excretion rate of 3-methylhistidine. Compensatory hypertrophy of the remnant kidney was significantly increased in the group treated with the high dose of IGF-I. These results suggest that IGF-I may have beneficial effects on somatic growth and nitrogen balance in renal insufficiency, with des-(1--3)IGF-I being particularly effective in reducing the rate of muscle protein breakdown.
在切除部分肾的年轻雄性大鼠中研究了胰岛素样生长因子I（IGF-I）对肾质量降低动物生长的促进作用。通过渗透微型泵以0.9和2.2mg·kg体重-1·天-1两种剂量给予重组人IGF-I 7天，以0.9mg·kg体重-1·天-1的剂量给予IGF-I的截短类似物des-(1-3)IGF-I。部分肾切除术导致肾功能明显受损，血清尿素和肌酐浓度升高、肌酐清除率降低以及平均每日尿量增加均证明了这一点。肾质量降低的动物的胴体组成发生了显著变化；水分含量增加而脂肪含量降低，而蛋白质含量保持不变。胴体组成不受IGF治疗的影响。在接受较低和较高剂量IGF-I治疗的大鼠以及接受des-(1-3)IGF-I治疗的大鼠中，治疗期间的体重增加、食物利用率和氮平衡均显著增加。des-(1-3)IGF-I组氮平衡的改善至少部分可以通过肌肉蛋白质分解速率的降低来解释，3-甲基组氨酸的尿排泄率降低表明了这一点。高剂量IGF-I治疗组残余肾的代偿性肥大显著增加。这些结果表明，IGF-I可能对肾功能不全时的体细胞生长和氮平衡有有益作用，des-(1-3)IGF-I在降低肌肉蛋白质分解速率方面特别有效。
