Manin M, Broer Y, Balage M, Rostene W, Grizard J
Laboratoire d'étude du Métabolisme Azoté, URA CNRS 164, Ceyrat, France.
Peptides. 1990 Jan-Feb;11(1):5-12. doi: 10.1016/0196-9781(90)90102-b.
Infusion of 125I-(Tyr A14)-insulin at tracer doses into the cerebrospinal fluid (CSF) resulted in a slow rate of increase in the CSF-labeled insulin during the first 2 hours with a plateau thereafter. Labeled insulin was cleared from the CSF at a higher rate than 3H-inulin, a marker of CSF bulk flow. The labeled insulin was mainly distributed in all the ventricular and periventricular brain regions. Small amounts of degraded insulin appeared in the CSF. Coinfusion with an excess of unlabeled insulin impaired the clearance and degradation of labeled insulin. It also inhibited the labeling in medial hypothalamus, olfactory bulbs and brain stem. In contrast, coinfusion of ribonuclease B (used to test the specificity of uptake) was without any effect. It was concluded that there is an active insulin intake from CSF into brain specific compartments that is presumably essential for the effects of insulin on brain function.
以示踪剂量将125I -（酪氨酸A14）胰岛素注入脑脊液（CSF），在最初2小时内CSF标记胰岛素的增加速率缓慢，此后达到平台期。标记胰岛素从CSF中的清除速率高于3H -菊粉（CSF总体流动的标志物）。标记胰岛素主要分布在所有脑室和脑室周围脑区。CSF中出现少量降解的胰岛素。与过量未标记胰岛素共同注入会损害标记胰岛素的清除和降解。它还抑制内侧下丘脑、嗅球和脑干中的标记。相比之下，共同注入核糖核酸酶B（用于测试摄取的特异性）没有任何影响。得出的结论是，存在从CSF到脑特定区域的活跃胰岛素摄取，这可能对胰岛素对脑功能的作用至关重要。
