Pollay M, Stevens F A
J Neurosci Res. 1980;5(2):163-72. doi: 10.1002/jnr.490050208.
The permeability of the blood brain barrier (BBB) to beta-hydroxybutyrate (beta-HB) was computed in fed and starved (five days) rats by the simultaneous measurement of cerebral blood flow (diffusible indicator method-123I-iodoantipyrine) and brain uptake of 14C-beta-HB (relative to a 3H2O reference). The results from the present study demonstrate that the movement of beta-HB across the BBB in rat is by a carrier-mediated process. During starvation, total movement (carrier-mediated and diffusionary) of this ketone body into brain was observed to be enhanced because of an increase in the diffusionary loss across the cerebral capillary. The calculated transport kinetics also suggest that the beta-HB molecule has a greater affinity for the transport (mediator) protein during starvation, although the maximal rate of uptake by brain due to a carrier processes mediated Vmax is decreased either because there is a smaller quantity of the mediating molecule or because there is trans inhibition by a high cellular concentration of beta-HB or some analog.
通过同时测量脑血流量（扩散指示剂法 - 123I - 碘安替比林）和14C-β-羟基丁酸（β-HB）的脑摄取量（相对于3H2O参考物），计算喂食和饥饿（五天）大鼠血脑屏障（BBB）对β-羟基丁酸（β-HB）的通透性。本研究结果表明，β-HB在大鼠体内穿过血脑屏障的过程是由载体介导的。在饥饿期间，由于脑毛细血管扩散损失增加，观察到这种酮体进入脑内的总移动（载体介导和扩散）增强。计算得出的转运动力学还表明，饥饿期间β-HB分子对转运（介导）蛋白具有更高的亲和力，尽管由于载体介导的Vmax过程导致脑摄取的最大速率降低，这要么是因为介导分子数量较少，要么是因为高细胞浓度的β-HB或某些类似物存在反式抑制。
