...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Journal of Cerebral Blood Flow and Metabolism: Official Journal of the International Society of Cerebral Blood Flow and Metabolism >Cerebral blood flow and brain oxygenation in rats breathing oxygen under pressure.
【24h】

Cerebral blood flow and brain oxygenation in rats breathing oxygen under pressure.

机译：在压力下呼吸氧气的大鼠的脑血流和脑氧合。

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Hyperbaric oxygen (HBO(2)) increases oxygen tension (PO(2)) in blood but reduces blood flow by means of O(2)-induced vasoconstriction. Here we report the first quantitative evaluation of these opposing effects on tissue PO(2) in brain, using anesthetized rats exposed to HBO(2) at 2 to 6 atmospheres absolute (ATA). We assessed the contribution of regional cerebral blood flow (rCBF) to brain PO(2) as inspired PO(2) (PiO(2)) exceeds 1 ATA. We measured rCBF and local PO(2) simultaneously in striatum using collocated platinum electrodes. Cerebral blood flow was computed from H(2) clearance curves in vivo and PO(2) from electrodes calibrated in vitro, before and after insertion. Arterial PCO(2) was controlled, and body temperature, blood pressure, and EEG were monitored. Scatter plots of rCBF versus PO(2) were nonlinear (R(2)=0.75) for rats breathing room air but nearly linear (R(2)=0.88-0.91) for O(2) at 2 to 6 ATA. The contribution of rCBF to brain PO(2) was estimated at constant inspired PO(2), by increasing rCBF with acetazolamide (AZA) or decreasing it with N-nitro-L-arginine methyl ester (L-NAME). At basal rCBF (78 mL/100 g min), local PO(2) increased 7- to 33-fold at 2 to 6 ATA, compared with room air. A doubling of rCBF increased striatal PO(2) not quite two-fold in rats breathing room air but 13- to 64-fold in those breathing HBO(2) at 2 to 6 ATA. These findings support our hypothesis that HBO(2) increases PO(2) in brain in direct proportion to rCBF.
机译：高压氧（HBO（2））增加血液中的氧张力（PO（2）），但通过O（2）诱导的血管收缩减少血流量。在这里，我们报告使用在2至6个绝对大气压（ATA）下暴露于HBO（2）的麻醉大鼠，对脑组织PO（2）的这些相对作用进行首次定量评估。我们评估了区域性脑血流量（rCBF）对脑PO（2）的影响，因为启发性PO（2）（PiO（2））超过了1 ATA。我们使用并置的铂电极同时测量纹状体中的rCBF和局部PO（2）。从体内H（2）清除曲线和插入前和插入后体外校准的电极的PO（2）计算脑血流量。控制动脉PCO（2），并监测体温，血压和EEG。对于大鼠呼吸室内空气，rCBF与PO（2）的散点图是非线性的（R（2）= 0.75），但在2到6个ATA时，O（2）的散点图几乎是线性的（R（2）= 0.88-0.91）。通过以乙酰唑胺（AZA）增加rCBF或以N-硝基-L-精氨酸甲酯（L-NAME）降低rCBF，在恒定吸气PO（2）时估计rCBF对脑PO（2）的贡献。在基础rCBF（78 mL / 100 g min）下，与室内空气相比，局部PO（2）在2至6 ATA时增加了7至33倍。 rCBF的增加使在呼吸室内空气的大鼠中纹状体PO（2）升高不至两倍，而在2至6 ATA时呼吸HBO（2）的大鼠中纹状体PO（2）升高13至64倍。这些发现支持我们的假设，即HBO（2）与rCBF成正比会增加大脑中的PO（2）。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号