Oxygen measurements in brain stem slices exposed to normobaric hyperoxia and hyperbaric oxygen
Oxygen measurements in brain stem slices exposed to normobaric hyperoxia and hyperbaric oxygen
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DOI：
10.1152/jappl.2001.90.5.1887
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发表时间：
2001-05-01
影响因子：
3.3
通讯作者：
Dean, JB
中科院分区：
文献类型：
--
作者：
Mulkey, DK;Henderson, RA;Dean, JB
我们以前报道过（J Appl Physiol 89：807-822，2000）少于或等于10分钟的高压氧（HBO 2;少于或等于2,468 Torr）刺激孤立的复合神经元。为了更好地定义高氧刺激，我们测量PO 2在300 μ m厚的大鼠延髓切片的孤立复合体，使用极谱碳纤维微电极，在灌注介质具有PO 2值范围从156到2,468托。在对照条件下，在1个绝对大气压下用95%O-2平衡的切片在其中心具有最小PO 2值（291 +/- 20 Torr），其类似于在完整中枢神经系统中测量的PO 2值（10-34 Torr）的10倍。在HBO 2期间，切片中心的PO 2从616 +/- 16 Torr增加到1，517 +/- 15 Torr。组织氧消耗倾向于在大于或等于1，675 Torr的中等PO 2下降低至与在代谢中毒切片（2-脱氧-D-葡萄糖和抗霉素A）的所有培养基中在PO 2下测得的值没有差异的水平。我们的结论是，在大多数脑切片研究中使用的控制介质是高氧在常压。在HBO 2期间，切片PO 2增加到似乎降低代谢的水平。
We previously reported (J Appl Physiol 89: 807-822, 2000) that less than or equal to 10 min of hyperbaric oxygen (HBO2; less than or equal to2,468 Torr) stimulates solitary complex neurons. To better define the hyperoxic stimulus, we measured PO2 in the solitary complex of 300-mum-thick rat medullary slices, using polarographic carbon fiber microelectrodes, during perfusion with media having PO2 values ranging from 156 to 2,468 Torr. Under control conditions, slices equilibrated with 95% O-2 at barometric pressure of 1 atmospheres absolute had minimum PO2 values at their centers (291 +/- 20 Torr) that were similar to 10-fold greater than PO2 values measured in the intact central nervous system (10-34 Torr). During HBO2, PO2 increased at the center of the slice from 616 +/- 16 to 1,517 +/- 15 Torr. Tissue oxygen consumption tended to decrease at medium PO2 greater than or equal to 1,675 Torr to levels not different from values measured at PO2 found in all media in metabolically poisoned slices (2-deoxy-D-glucose and antimycin A). We conclude that control medium used in most brain slice studies is hyperoxic at normobaric pressure. During HBO2, slice PO2 increases to levels that appear to reduce metabolism.