Price D A, Wit J M, van Buul-Offers S, Korteland-van Male A M, van Rooyen-Wehmeijer A K, Hoogerbrugge C, Van den Brande J L
Endocrinology. 1979 Sep;105(3):851-61. doi: 10.1210/endo-105-3-851.
Serum somatomedin activity (SM-act) and cartilage metabolism were compared in acutely fasted, marasmic (M), and marasmic kwashiorkor (MK) rats. SM-act was estimated in the porcine bioassay. In vitro uptake of [35S]sulfate and [3H]methylthymidine in costal cartilage of the experimental animals during an incubation in medium immediately after sacrifice, called endogenous activity, and the effect of incubation in 20% normal human plasma after a preincubation of 22 h in medium only, called plasma responsiveness", were determined. Acutely fasted rats had lowered SM-act and a circulating heat-labile inhibitor. Endogenous activity and responsiveness of cartilage were depressed. MK rats (fed ad libitum a 0.5% casein, isocaloric food) showed a profound depression of growth and cartilage endogenous activity despite only partially reduced SM-act and increased responsiveness. M rats received normal food and were pair-fed with MK rats, consuming approximately 0.08 g/g BW . day. They showed very depressed SM-act and low endogenous activity, and responsiveness was increased, though less than in the MK rats. On refeeding M rats, SM-act and cartilage responsiveness increased, followed by an increase of endogenous activity. Catch-up growth was best related to [3H]methylthymidine incorporation by cartilage (endogenous activity). In conclusion, these two types of experimental chronic malnutrition induce a more diversified pattern than does acute fasting. During malnutrition, cartilage metabolism does not reflect bioassayable SM-act of serum but rather the other effects of the nutritional insult. On refeeding, the expected relationship of SM-act and cartilage metabolism is rapidly restored.
对急性禁食、消瘦（M）和消瘦型夸希奥科病（MK）大鼠的血清生长介素活性（SM-act）和软骨代谢进行了比较。采用猪生物测定法估算SM-act。在处死实验动物后立即于培养基中孵育期间，测定其肋软骨对[35S]硫酸盐和[3H]甲基胸苷的体外摄取量，即所谓的内源性活性，以及在仅在培养基中预孵育22小时后于20%正常人血浆中孵育的效果，即所谓的血浆反应性。急性禁食大鼠的SM-act降低且存在一种循环热不稳定抑制剂。软骨的内源性活性和反应性受到抑制。MK大鼠（随意喂食0.5%酪蛋白等热量食物）尽管SM-act仅部分降低且反应性增加，但生长和软骨内源性活性却显著降低。M大鼠给予正常食物并与MK大鼠配对喂养，每日每克体重消耗约0.08克食物。它们的SM-act非常低，内源性活性也低，反应性增加，不过低于MK大鼠。重新喂养M大鼠后，SM-act和软骨反应性增加，随后内源性活性增加。追赶生长与软骨对[3H]甲基胸苷的掺入（内源性活性）最相关。总之，这两种实验性慢性营养不良比急性禁食诱导出更多样化的模式。在营养不良期间，软骨代谢并不反映血清中可生物测定SM-act，而是反映营养损伤的其他影响。重新喂养后，SM-act与软骨代谢的预期关系迅速恢复。
