Oxygen consumption in the avascular guinea pig retina
Oxygen consumption in the avascular guinea pig retina
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DOI：
10.1152/ajpheart.1996.271.3.h1162
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发表时间：
1996-09-01
影响因子：
4.8
通讯作者：
Yu, P
中科院分区：
文献类型：
--
作者：
Cringle, S;Yu, DY;Yu, P
以前没有研究过具有天然无血管视网膜的哺乳动物的整个视网膜的氧消耗。通过视网膜内氧分布的空间分析在体内测量豚鼠无血管视网膜的氧消耗。豚鼠视网膜的无血管性质允许将内层视网膜包括在分析中，而不破坏视网膜的正常生理状态。氧敏微电极（1 μ m尖端）用于通过麻醉机械通气豚鼠（n = 10）的视网膜进行高分辨率氧张力测量。然后分析氧分布作为离脉络膜毛细血管/布鲁赫膜的距离的函数的氧张力，并将数据拟合到已建立的视网膜氧消耗的数学模型。豚鼠视网膜全层的平均耗氧量为1.1 +/- 0.09 ml O-2。min（-1）。100 g（-1）（n = 10）。视网膜外半部的平均耗氧量为2.07 +/- 0.17 ml O-2。min（-1）。100 g（-1），而内半部分仅为0.12 +/- 0.04 ml O-2。min（-1）。100 g（-1）。在每种情况下，在外层视网膜中确定了局部高氧消耗区域，该区域平均占总视网膜氧消耗的93.9 +/- 2.0%。只有5.2 +/- 1.4%的总耗氧量可归因于视网膜的内半部分。当脉络膜氧分压通过全身性高氧和高碳酸血症的组合而增加时，高氧水平可以在视网膜的所有层中维持。在这些过量供氧的条件下，内层视网膜仍然仅消耗0.45 +/- 0.11 ml O-2。min（-1）。100 g（-1），占视网膜总耗氧量的13.8 +/- 2.5%。豚鼠内层视网膜的相对较低的耗氧量可能反映了对该物种中缺乏视网膜循环所施加的限制的有趣的适应。
Oxygen consumption across the retina of a mammal with a naturally avascular retina has not previously been investigated. The oxygen consumption across the avascular retina of the guinea pig was measured in vivo by spatial analysis of the intraretinal oxygen profile. The avascular nature of the guinea pig retina allows the inner retina to be included in the analysis without disrupting the normal physiological state of the retina. Oxygen-sensitive microelectrodes (1-mu m tip) were used to make high-resolution measurements of oxygen tension through the retina of anesthetized, mechanically ventilated guinea pigs (n = 10). Oxygen profiles were then analyzed in terms of oxygen tension as a function of distance from the choriocapillaris/Bruch's membrane, and the data were fitted to an established mathematical model of retinal oxygen consumption. The average oxygen consumption of the full thickness of the guinea pig retina was 1.1 +/- 0.09 ml O-2 . min(-1). 100 g(-1) (n = 10). The average oxygen consumption of the outer half of the retina was 2.07 +/- 0.17 ml O-2 . min(-1). 100 g(-1), while that of the inner half was only 0.12 +/- 0.04 ml O-2 . min(-1). 100 g(-1). A localized region of high oxygen consumption was identified in the outer retina in every case, and this region accounted for an average of 93.9 +/- 2.0% of the total retinal oxygen consumption. Only 5.2 +/- 1.4% of the total oxygen consumption was attributable to the inner half of the retina. When choroidal oxygen tension was increased via a combination of systemic hyperoxia and hypercapnia, high oxygen levels could be sustained in all retinal layers. Under these conditions of an excess oxygen supply, the inner retina still consumed only 0.45 +/- 0.11 ml O-2 . min(-1). 100 g(-1), which was 13.8 +/- 2.5% of the total retinal oxygen consumed. The relatively low oxygen consumption in the inner retina of the guinea pig may reflect an interesting adaptation to the constraints imposed by the absence of a retinal circulation in this species.