Cornford E M, Braun L D, Oldendorf W H
Pediatr Res. 1982 Apr;16(4 Pt 1):324-8. doi: 10.1203/00006450-198204000-00017.
The intracarotid injection technique has been utilized to examine blood-brain barrier function in studies of newborn (greater than 24 h), 7, 14, 21 and 28 day-old, as well as adult rabbits. The age-related modulations in blood-brain barrier transport of adenine, arginine, choline, lactate and tryptophan were defined and demonstrated to be independent of each other. Lactic acid uptake was unusual in that the brain uptake index (BUI) was found to be greatest at 7 days postpartum. Elevated lactate uptake continues until 14 days and is then reduced. As indicated below, for all of the other metabolites examined, a maximal BUI was observed in the newborn brain and BUIs typically showed some sort of inverse relationship to animal age. The BUI of arginine is apparently halved in the first 7 days postnatally, and continues to decrease, reaching the value seen for the adult rabbit by an age of 21 days. In contrast, the brain uptake of adenine is unusual in that there appears to be a very gradual reduction in brain uptake occurring throughout the suckling period. A 3-fold decrease in the BUI of choline was observed during the first 2 wk postpartum. Tryptophan uptake undergoes a 4-fold reduction in the first 4 wk postnatally . Only minor variations in the uptakes of glucose and butanol (a reference substance which is completely cleared by brain over a wide range of blood flow rates) were observed over the range of ages examined. Therefore modulations in adenine, arginine, choline, lactate and tryptophan permeability are not attributable to blood flow alterations.
在新生（大于24小时）、7日龄、14日龄、21日龄、28日龄以及成年兔的研究中，已采用颈内注射技术来检测血脑屏障功能。已明确腺嘌呤、精氨酸、胆碱、乳酸和色氨酸的血脑屏障转运中与年龄相关的调节作用，且这些调节作用相互独立。乳酸摄取情况较为特殊，因为发现产后7天时脑摄取指数（BUI）最大。升高的乳酸摄取持续至14天，之后降低。如下所示，对于所有其他检测的代谢物，在新生兔脑中观察到最大的BUI，且BUI通常与动物年龄呈某种反比关系。精氨酸的BUI在出生后的前7天内明显减半，并持续下降，到21日龄时达到成年兔的水平。相比之下，腺嘌呤的脑摄取情况较为特殊，因为在整个哺乳期脑摄取似乎有非常缓慢的下降。产后前2周内观察到胆碱的BUI下降了3倍。色氨酸摄取在出生后的前4周内下降了4倍。在所研究的年龄范围内，仅观察到葡萄糖和丁醇（一种参考物质，在很宽的血流速率范围内能被脑完全清除）摄取的微小变化。因此，腺嘌呤、精氨酸、胆碱、乳酸和色氨酸通透性的调节并非归因于血流改变。
