DIFFUSION OF O-2 IN THE RETINA OF ANESTHETIZED MINIATURE PIGS IN NORMOXIA AND HYPEROXIA
DIFFUSION OF O-2 IN THE RETINA OF ANESTHETIZED MINIATURE PIGS IN NORMOXIA AND HYPEROXIA
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DOI：
10.1016/0014-4835(89)90045-6
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发表时间：
1989-09-01
影响因子：
3.4
通讯作者：
STROMMER, K
中科院分区：
文献类型：
--
作者：
POURNARAS, CJ;RIVA, CE;STROMMER, K
应用双管凹陷式微电极同时测定小型猪视网膜内氧分压（pO2）和局部视网膜电图（ERG）。在正常氧和高氧期间，记录了接近（近动脉）或远离（血管间）视网膜小动脉的区域的经视网膜pO2分布。在常氧下，在两个区域中，从视网膜内层和脉络膜向视网膜中部的pO2降低。在视网膜内层的近动脉pO2曲线的梯度比血管间曲线的梯度陡。在100%O2的呼吸期间，该特征持续存在。分析的pO2档案表明，即使在高氧，脉络膜不能供应O2到整个视网膜。结果也支持先前工作的结论（Riva，Pournaras和Tsacopoulos，1986），表明在正常视网膜中，不是从脉络膜扩散到视网膜小动脉的O2引起这些血管的血管收缩。在小型猪中，这种收缩似乎在高氧期间将视网膜内层组织pO2维持在恒定水平。从pO2 transretinal配置文件和以前发表的脉络膜O2通量和pO2值视网膜血管附近的解释性工作假设，制定根据该O2消耗（qO2）的外层视网膜增加在高氧在小型猪。
Intraretinal oxygen tension (pO2) and local electroretinogram (ERG) were simultaneously measured in miniature pigs using double-barreled recess type microelectrodes. Transretinal pO2 profiles were recorded during normoxia and hyperoxia in areas close to (juxta-arteriolar) or far from (intervascular) retinal arterioles. In normoxia, in both areas, the pO2 decreased from the inner retina and the choroid towards the middle of the retina. In the inner retina the gradient of the juxta-arteriolar pO2 profile was steeper than that of the intervascular profile. This characteristic persisted during the breathing of 100% O2. Analysis of the pO2 profiles shows that, even in hyperoxia, the choroid cannot supply O2 to the whole retina. The results also support the conclusions of previous work (Riva, Pournaras and Tsacopoulos, 1986) indicating that in the normal retina it is not the O2 diffusing from the choroid to the retinal arterioles that induces vasoconstriction of these vessels. In the miniature pig this constriction appears to maintain inner retina tissue pO2 at a constant level during hyperoxia. From the pO2 transretinal profiles and previously published choroidal O2 fluxes and pO2 values near retinal vessels an explanatory working hypothesis is formulated according to which O2 consumption (qO2) of the outer retina increases during hyperoxia in the miniature pig.