The Effect of Aging on Intestinal Absorption at the Level of Membrane Biology.

[老化对刷状缘膜处的葡萄糖摄取的影响] 使用快速渗透现象研究14 C-d-葡萄糖的摄取。在钠梯度下，d-葡萄糖摄取的时程表现出经典的超调，其摄取峰值位于30秒。平衡时葡萄糖的摄取量为200pmol/mg蛋白质。在钾梯度下没有观察到过冲。这些数据表明，使用该实验的囊泡没有任何细胞器或基底侧膜的污染。老年组48月龄大鼠在钠梯度下未出现超调现象。老年大鼠在钠梯度下30秒时的葡萄糖摄取量为480 pmol/mg蛋白质，几乎是对照大鼠的一半。与对照大鼠相比，老年大鼠在钾梯度条件下表现出更高的葡萄糖摄取。这些数据表明葡萄糖转运的功能随着年龄的增长而变化。

[Effect of Aging on Glucose Uptake at the Brush Border Membrane]The uptake of ^<14>C-d-Glucose was investigated using rapid infiltration technique. Under the sodium gradient, the time course of the d-glucose uptake showed classical overshoot and its peak of the uptake was located at the 30 seconds. The uptake of glucose at the equilibrium was 200pmol/mg protein. No overshoot phenomenon was noted under the potassium gradient. These data depicted that the vesicles which used this experiment had not any contamination of cell organelles or basal lateral membranes. In the aged group, 48 months old rats, didn't showed overshoot phenomenon under the sodium gradient. The glucose uptake at the 30 seconds under the sodium gradient of the aged rats depicted 480 pmol/mg protein which was almost half amount of the control rats. The aged rats showed higher glucose uptake under the potassium gradient condition compared to the control rats. These data suggested that the functional changing of dーglucose transport with age.