Friedman A L, Jax D K, Chesney R W
Pediatr Res. 1981 Jan;15(1):10-13. doi: 10.1203/00006450-198101000-00003.
Isolated renal tubules were prepared from newborn and adult Sprague-Dawley rats. They were used to study the uptake and accumulation of the beta-amino acid, taurine, by renal epithelium. Initial rate as well as steady-state kinetics were studied. Initial rate studies revealed heterogeneity of uptake in newborn and adult tubules. Slower uptake was present in the newborn in the low-affinity system. Slowed efflux was found in neonatal tissue. Newborn tubules in contrast to adult tubules demonstrated uptake under anaerobic conditions. Adult and newborn tissues showed decreased uptake of taurine when incubated with beta-alanine. Physiologic taurinuria, be it in the rat or man, may be due to less rapid initial uptake and/or efflux from ren in neonatal tissue. Newborn tubules in contrast to adult tubules demonstrated uptake under anaerobic conditions. Adult and newborn tissues showed decreased uptake of taurine when incubated with beta-alanine. Physiologic taurinuria, be it in the rat or man, may be due to less rapid initial uptake and/or efflux from ren in neonatal tissue. Newborn tubules in contrast to adult tubules demonstrated uptake under anaerobic conditions. Adult and newborn tissues showed decreased uptake of taurine when incubated with beta-alanine. Physiologic taurinuria, be it in the rat or man, may be due to less rapid initial uptake and/or efflux from renal epithelium.
从新生和成年Sprague-Dawley大鼠制备分离的肾小管。它们被用于研究肾上皮细胞对β-氨基酸牛磺酸的摄取和积累。研究了初始速率以及稳态动力学。初始速率研究揭示了新生和成年肾小管摄取的异质性。在低亲和力系统中，新生肾小管的摄取较慢。在新生组织中发现流出减缓。与成年肾小管相比，新生肾小管在厌氧条件下表现出摄取。当与β-丙氨酸一起孵育时，成年和新生组织对牛磺酸的摄取减少。无论是在大鼠还是人类中，生理性牛磺酸尿症可能是由于新生组织中肾上皮细胞的初始摄取和/或流出速度较慢所致。与成年肾小管相比，新生肾小管在厌氧条件下表现出摄取。当与β-丙氨酸一起孵育时，成年和新生组织对牛磺酸的摄取减少。无论是在大鼠还是人类中，生理性牛磺酸尿症可能是由于新生组织中肾上皮细胞的初始摄取和/或流出速度较慢所致。与成年肾小管相比，新生肾小管在厌氧条件下表现出摄取。当与β-丙氨酸一起孵育时，成年和新生组织对牛磺酸的摄取减少。无论是在大鼠还是人类中，生理性牛磺酸尿症可能是由于肾上皮细胞的初始摄取和/或流出速度较慢所致。
