Cheeseman C I, Thomson A B, Walker K
Radiat Res. 1985 Jan;101(1):131-43.
The time course of the effect of exposure to sublethal irradiation on transport of several substrates by the intestine has been studied using isolated enterocytes. Rats received a single dose of 6 Gy to the abdomen, and isolated intestinal epithelial cells were prepared 3, 7, and 14 days later. The ability of the cells to take up D-glucose, L-leucine, and glycyl-L-leucine was assessed using 2.5-min incubation periods and was compared with the uptake in control cells. It was found that the protein content of the cells increased after irradiation, and although some of this was the result of increased binding of albumin to the cells there was also a nonspecific increase in most cell proteins. Consequently uptake data were expressed per unit number of cells and not per milligram of cell protein. Comparison of uptake expressed in this way showed that D-glucose and glycyl-L-leucine uptake was elevated 3 days after irradiation while that of L-leucine was unaffected. By 14 days after irradiation the glucose and glycyl-L-leucine uptake had returned to normal but the L-leucine transport was depressed. These data indicate that the effects of irradiation upon substrate transport in the intestines are not uniform and that although the cell population is initially reduced the remaining cells can compensate by increasing their transport capacity.
利用分离的肠上皮细胞，研究了亚致死剂量辐射对肠道几种底物转运影响的时间进程。给大鼠腹部单次照射6 Gy剂量，3天、7天和14天后制备分离的肠上皮细胞。使用2.5分钟的孵育期评估细胞摄取D-葡萄糖、L-亮氨酸和甘氨酰-L-亮氨酸的能力，并与对照细胞的摄取情况进行比较。发现照射后细胞蛋白质含量增加，虽然部分原因是白蛋白与细胞的结合增加，但大多数细胞蛋白质也有非特异性增加。因此，摄取数据以每单位细胞数而非每毫克细胞蛋白质来表示。以这种方式表示的摄取比较表明，照射后3天D-葡萄糖和甘氨酰-L-亮氨酸的摄取增加，而L-亮氨酸的摄取未受影响。照射后14天，葡萄糖和甘氨酰-L-亮氨酸的摄取恢复正常，但L-亮氨酸转运受到抑制。这些数据表明，辐射对肠道底物转运的影响并不一致，尽管细胞数量最初会减少，但剩余细胞可以通过增加其转运能力来进行补偿。
