MacNeill C, Bryan R M
Department of Surgery (Neurosurgery), Milton S. Hershey Medical Center, Pennsylvania State University, Hershey 17033.
J Cereb Blood Flow Metab. 1988 Aug;8(4):495-501. doi: 10.1038/jcbfm.1988.90.
Regional cerebral glucose utilization (rCMRglu) was studied during mild hypoxic hypoxia in awake free-ranging rats. Rats were prepared with chronic arterial and venous catheters and placed in individual chambers for 4 days to recover from surgery before the experiments. The catheters were accessible by passing them through the top of the chambers. Hypoxia was induced by filling the chambers with a gas mixture consisting of 11% O2 in a balance of N2. Regional CMRglu and physiological parameters were measured in normoxic controls and in rats that had been hypoxic for 2 and 17 min before beginning the measurements. Regional CMRglu was measured in 17 brain regions using [6-14C]glucose. PaO2 decreased from 88 mm Hg in the controls to approximately 40 mm Hg during hypoxia. In the early stages of hypoxia (2-12 min), rCMRglu increased approximately 10-25% above the control rates. In later stages of hypoxia (17-27 min), rCMRglu was not different from that in the normoxic controls. The increase in rCMRglu in the early hypoxia was not blocked by propranolol (1.4 mg/kg), indicating that beta-adrenergic receptors were not involved with the increase in rCMRglu. It was concluded that mild hypoxia is associated with an increased rate of cerebral glucose utilization; however, the increase is transitory, with glucose utilization returning to control rates before 17 min.
在清醒自由活动的大鼠轻度低氧性缺氧期间，对局部脑葡萄糖利用率（rCMRglu）进行了研究。给大鼠植入慢性动脉和静脉导管，并将它们置于单独的实验箱中4天，以便在实验前从手术中恢复。导管可通过实验箱顶部引出。通过向实验箱中充入含11%氧气和其余为氮气的混合气体来诱导缺氧。在常氧对照组以及在开始测量前分别缺氧2分钟和17分钟的大鼠中，测量局部CMRglu和生理参数。使用[6-14C]葡萄糖测量17个脑区的局部CMRglu。缺氧期间，动脉血氧分压（PaO2）从对照组的88毫米汞柱降至约40毫米汞柱。在缺氧早期（2 - 12分钟），rCMRglu比对照组速率增加约10 - 25%。在缺氧后期（17 - 27分钟），rCMRglu与常氧对照组无差异。早期缺氧时rCMRglu的增加未被普萘洛尔（1.4毫克/千克）阻断，这表明β-肾上腺素能受体与rCMRglu的增加无关。得出的结论是，轻度缺氧与脑葡萄糖利用率增加有关；然而，这种增加是暂时的，葡萄糖利用率在17分钟前恢复到对照速率。
