Ward W F
Department of Physiology, University of Texas Health Science Center, San Antonio.
J Gerontol. 1988 Mar;43(2):B50-3. doi: 10.1093/geronj/43.2.b50.
Age-related changes in liver protein synthesis of ad libitum fed and food-restricted SPF Fischer 344 rats have been measured. In ad libitum fed animals, valine incorporation increased from 3 to 6 mo of age, decreased to the 3-mo level at 12 mo, remained relatively constant through 18 mo, and then declined further at 24 mo of age. By 24 mo valine incorporation was 30% of the 6-mo value. Food restriction had no effect at 3 mo of age (6 wk of restriction) but at 6 mo the rate of valine incorporation was 35% greater than the control, an increment that was maintained throughout the life of the animal. Therefore, although food restriction does not prevent the age-related decline in protein synthesis, it does maintain the rate of liver valine incorporation at levels greater than those observed in the liver of the ad libitum fed animal.
已经测定了随意进食和食物受限的无特定病原体（SPF）费希尔344大鼠肝脏蛋白质合成的年龄相关变化。在随意进食的动物中，缬氨酸掺入量在3至6月龄时增加，在12月龄时降至3月龄水平，在18月龄时保持相对稳定，然后在24月龄时进一步下降。到24月龄时，缬氨酸掺入量为6月龄值的30%。食物限制在3月龄（限制6周）时没有影响，但在6月龄时，缬氨酸掺入率比对照组高35%，这一增加在动物的整个生命过程中都保持着。因此，尽管食物限制不能阻止与年龄相关的蛋白质合成下降，但它确实能将肝脏缬氨酸掺入率维持在高于随意进食动物肝脏中观察到的水平。
