Reynolds R, Roth K S, Hwang S M, Segal S
Biochim Biophys Acta. 1978 Aug 4;511(2):274-84. doi: 10.1016/0005-2736(78)90320-6.
The initial uptake of glycine by renal cortical slices from newborn Sprague-Dawley and Long-Evans rats is the same as that observed in adult tissues. Both newborn and adult tissue possess similar high and low affinity glycine transport systems which require an examination of velocity measurements over a wide range of concentration (0.02--50.0 mM) for their discernment. Initial rates of glycine uptake by isolated renal tubule fragments from newborn and adults are similar at a physiological substrate concentration but at high glycine levels there appears to be a decrease in velocity of uptake (V) associated with the high Km system in the young. Whatever preparation of renal cortex is studied, there is a consistent finding that immature tissue is able to accumulate much higher intracellular levels of glycine than the adult, a finding consistent with slower efflux from the cell. An interpretation of the etiology of physiologic aminoaciduria in young animals should take this into account.
新生斯普拉格-道利大鼠和长-伊文斯大鼠肾皮质切片对甘氨酸的初始摄取与成年组织中观察到的情况相同。新生组织和成年组织都拥有相似的高亲和力和低亲和力甘氨酸转运系统，需要在很宽的浓度范围（0.02 - 50.0 mM）内检查速度测量值才能辨别它们。在生理底物浓度下，新生和成年分离的肾小管片段对甘氨酸的摄取初始速率相似，但在高甘氨酸水平时，幼龄动物中与高Km系统相关的摄取速度（V）似乎会降低。无论研究哪种肾皮质制剂，都有一个一致的发现，即未成熟组织能够积累比成年组织高得多的细胞内甘氨酸水平，这一发现与细胞内流出较慢一致。对幼龄动物生理性氨基酸尿病因的解释应考虑到这一点。
