Rühle H J, Russell J A, Ermisch A, Landgraf R
Department of Cell Biology and Regulation, University of Leipzig, Germany.
Neuropeptides. 1992 Jun;22(2):117-24. doi: 10.1016/0143-4179(92)90066-6.
The effects of circulating oxytocin on permeability of the blood-brain barrier (BBB) to L-[3H]leucine were studied in anaesthetized rats using the intracarotid, single pass, bolus injection technique. After bolus intracarotid oxytocin injection (10(-9) M), there were no differences in [3H]leucine uptake, compared with controls, in any of eight brain regions with a 'tight' BBB (olfactory bulb, frontal cortex, visual cortex, corpus striatum, hippocampus, thalamus, hypothalamus and colliculi) or in BBB-free, 'leaky' structures (pineal gland, choroid plexus, neuro-intermediate pituitary, anterior pituitary). [3H]leucine uptake by the 'leaky' structures was 2.4x and 2.6x uptake by 'tight' regions in the oxytocin and control groups respectively. In morphine-dependent rats, naloxone increased oxytocin secretion 28-fold within 5 min, but did not affect [3H]leucine uptake for any BBB-protected brain region or BBB-free 'leaky' structure. Accumulation of [3H]leucine was 8.3x and 7.0x greater in the 'leaky' structures than in the 'tight' regions in the naloxone and control groups respectively; [14C]inulin accumulation by each 'tight' region (measured simultaneously with [3H]leucine to determine the vascular space) was not affected by naloxone. It is concluded that even very high blood plasma concentrations of oxytocin do not affect BBB permeability for leucine. It is unlikely that altered BBB permeability, at least for amino acids, contributes to CNS changes during naloxone-provoked morphine withdrawal.
采用颈内动脉单次推注技术，在麻醉大鼠中研究了循环催产素对血脑屏障（BBB）对L-[3H]亮氨酸通透性的影响。在颈内动脉推注催产素（10^(-9) M）后，与对照组相比，在具有“紧密”血脑屏障的八个脑区（嗅球、额叶皮质、视觉皮质、纹状体、海马体、丘脑、下丘脑和丘状体）或无血脑屏障的“渗漏”结构（松果体、脉络丛、神经垂体中间部、垂体前叶）中，[3H]亮氨酸摄取均无差异。在催产素组和对照组中，“渗漏”结构对[3H]亮氨酸的摄取分别是“紧密”区域的2.4倍和2.6倍。在吗啡依赖大鼠中，纳洛酮在5分钟内使催产素分泌增加28倍，但对任何受血脑屏障保护的脑区或无血脑屏障的“渗漏”结构的[3H]亮氨酸摄取均无影响。在纳洛酮组和对照组中，“渗漏”结构中[3H]亮氨酸的积累分别比“紧密”区域高8.3倍和7.0倍；纳洛酮对每个“紧密”区域（与[3H]亮氨酸同时测量以确定血管空间）的[14C]菊粉积累无影响。得出的结论是，即使血浆中催产素浓度非常高，也不会影响血脑屏障对亮氨酸的通透性。至少对于氨基酸而言，血脑屏障通透性改变不太可能是纳洛酮诱发吗啡戒断期间中枢神经系统变化的原因。
