Harik S I, Behmand R A, LaManna J C
Department of Neurology, University Hospitals of Cleveland, Ohio.
J Appl Physiol (1985). 1994 Aug;77(2):896-901. doi: 10.1152/jappl.1994.77.2.896.
Prolonged hypoxia causes several adaptive changes in systemic physiology and tissue metabolism. We studied the effects of hypobaric hypoxia on glucose transport at the blood-brain barrier (BBB) in the rat. We found that hypoxia increased the density of brain microvessels seen on immunocytochemical stains using an antibody to the glucose transporting protein GLUT. In addition, we found that hypoxia increased the density of GLUT in isolated cerebral microvessels as determined by specific cytochalasin B binding. The higher GLUT density in isolated cerebral microvessels was evident after 1 wk of hypoxia and was associated with decreased activity of gamma-glutamyltranspeptidase. Consistent with these findings, we also demonstrated that 3 wk of hypobaric hypoxia caused increased unidirectional transport of glucose at the BBB in several brain regions in vivo, as determined by the doubly labeled single-pass indicator-fractionation atrial bolus injection method in anesthetized rats. We conclude that chronic hypobaric hypoxia is associated with increased glucose transport at the BBB.
长期缺氧会导致全身生理和组织代谢发生多种适应性变化。我们研究了低压缺氧对大鼠血脑屏障（BBB）葡萄糖转运的影响。我们发现，使用针对葡萄糖转运蛋白GLUT的抗体进行免疫细胞化学染色时，缺氧会增加脑微血管的密度。此外，我们发现，通过特异性细胞松弛素B结合测定，缺氧会增加分离的脑微血管中GLUT的密度。缺氧1周后，分离的脑微血管中较高的GLUT密度明显可见，且与γ-谷氨酰转肽酶活性降低有关。与这些发现一致，我们还证明，通过麻醉大鼠的双标记单通道指示剂-分级心房推注注射法测定，3周的低压缺氧会导致体内几个脑区血脑屏障处葡萄糖的单向转运增加。我们得出结论，慢性低压缺氧与血脑屏障处葡萄糖转运增加有关。
