Carbogen气体对大鼠前部脉络膜血流量的影响

Effects on carbogen gas to the anterior choroidal blood flow in rats

目的 观察纯氧和carbogen( 95 %O2 +5 %CO2 )对正常大鼠前部脉络膜血流量的影响。方法 使大鼠吸入不同的气体 ,应用激光多普勒血流仪测量其前部脉络膜血流灌注量 ,并同步分析动脉血气变化。结果 ( 1)大鼠前部脉络膜血流量在呼吸carbogen时较呼吸空气时显著性升高 (P <0 0 1) ;呼吸纯氧时与呼吸空气时相比无显著性差异 (P >0 0 5 )。 ( 2 )呼吸纯氧或carbogen的大鼠动脉血氧分压 (PO2 )、血氧饱和度 (SaO2 )均比呼吸空气组明显提高 (P <0 0 5 ) ,且 2组相比无差异 (P >0 0 5 )。结论 ( 1)carbogen气体可增加大鼠前部脉络膜血流灌注 ,较呼吸纯氧更有利于组织供氧。 ( 2 )

ObjectiveTo determine the effects of systemic hyperoxia and hypercapnia on anterior choroidal bood flow in anesthetized rats,during pure oxygen (100%O 2) or carbogen (95%O 2+5%CO 2) breathing.MethodBy using laser Doppler flowmery,blood flow from the anterior choroid in Urethane anesthetized adult rats were measured continuously.After basal choroidal blood flow was stable in ambient room air breathing,experimental gas (oxygen or carbogen) was given to replace the room air in the sealed cabin.When the experimental gas replaced the room air completely,choroidal blood flow was recorded at 20 minutes.At the end of experimental gas breathing,blood gas analyses from the descending aorta were obtained to evaluate the effects of breathing.Results① Compared with ambient room air breathing,the choroidal blood flow increased during carbogen breathing ( P <0 01),but was not altered by pure O 2 breathing ( P >0 05).② Although hemoglobin oxygen saturation level (SaO 2),partial pressure of oxygen (PO 2) were increased by pure O 2 and carbogen breathing,they had no differences between pure O 2 and carbogen breathing.Compared with room air breathing,partial pressure of carbon dioxide (PCO 2) was increased after carbogen breathing ( P <0 01),whereas decreased after pure O 2 breathing ( P <0 01).Conclusion① Carbogen can increase anterior choroidal blood flow in rats,and it can provide better oxygenation compared with pure O 2.② The anterior choroidal blood flow in rats is not sensitive to the concentration of O 2 in breathing gas,whereas the concentration of CO 2 can influence choroidal blood flow remarkably.