Pénzes L, Boross M
Aktuelle Gerontol. 1978 Feb;8(2):101-7.
Glucose absorption from the ageing rat's small intestine was studied "in vivo" using the recirculation-perfusion method of Sheff and Smyth. Different initial concentrations were used and animals of various ages (6 mo., 12 mo. and more than 27 mo. old) tested for their glucose uptake from the total small intestine (including duodenum) in the course of a twenty-minute period. Glucose was estimated by the modified o-toluidine method of Hultman. The (reciprocal) absorption data, reduced on dried intestine weight units were plotted by the Lineweaver -- Burk (regression) equations and the Km and Vmax indices derived. The results show that there is an apparent increase of the Km value in case of the old rats. Regarding the Km as an apparent affinity constant of the glucose for the carrier transport, ageing induces a considerable loss in affinity and a concomitant increase of the maximum absorptive capacity (Vmax) possible by the transfer capacity of the ageing small gut. The interpretation of the data suggest that the role of the probable age-dependent changes of diffusion-components cannot be ruled out.
采用谢夫和史密斯的再循环灌注法，“在体”研究了老龄大鼠小肠对葡萄糖的吸收。使用了不同的初始浓度，并对不同年龄（6个月、12个月和27个月以上）的动物在20分钟内从小肠（包括十二指肠）对葡萄糖的摄取情况进行了测试。葡萄糖采用胡尔特曼改良的邻甲苯胺法进行测定。将以干肠重量单位换算后的（倒数）吸收数据用林维韦-伯克（回归）方程作图，并得出Km和Vmax指数。结果表明，老龄大鼠的Km值明显升高。将Km视为葡萄糖对载体转运的表观亲和常数，衰老会导致亲和力显著丧失，同时衰老小肠的转运能力可能使最大吸收能力（Vmax）增加。对数据的解释表明，不能排除扩散成分可能随年龄变化的作用。
