Retinal arterial occlusion leads to acidosis in the cat
Retinal arterial occlusion leads to acidosis in the cat
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DOI：
10.1016/j.exer.2004.11.002
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发表时间：
2005-04-01
影响因子：
3.4
通讯作者：
Linsenmeier, RA
中科院分区：
文献类型：
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作者：
Birol, G;Budzynski, E;Linsenmeier, RA
本研究通过在空气和 100% O-2 通气下测量视网膜细胞外 H+ 浓度 (H+](O)) 来研究视网膜动脉闭塞期间 pH 值的变化。通过用探针按压视网膜动脉，在完整的麻醉猫中产生闭塞。 [H+]，用 pH 敏感微电极记录整个视网膜的轮廓。即使在 100% O-2 通气条件下，平均内部视网膜 [H+] 在遮挡期间增加，导致酸化高达 0.10 pH 单位。由于间隙受损，在遮挡期间，内部视网膜 H+ 轮廓强度降低。即使在遮挡期间外视网膜 H+ 产生没有增加，平均外视网膜 H+ 轮廓强度也增加了。这可能是由于 H+ 从内视网膜扩散到外视网膜，这与正常视网膜中的通量相反。再灌注后，[H+](o)恢复到其闭塞前值。综上所述，动脉闭塞导致视网膜酸化。闭塞期间增强的氧合作用并没有减少这种酸化。这可以解释为什么通过增强 O-2 呼吸增加视网膜中的 PO2 可以改善遮挡期间和之后的视网膜功能，但不能完全逆转遮挡的影响。 (c) 2004 Elsevier Ltd. 保留所有权利。
This study investigated the changes in pH during retinal artery occlusion by means of extracellular H+ concentration (H+](O)) measurements in the retina under both air and 100% O-2 ventilation. Occlusion was produced in intact anesthetised cats by pressing with a probe onto a retinal artery. [H+], profiles were recorded across the retina with pH sensitive microelectrodes. The average inner retinal [H+], increased during occlusion, resulting in an acidification of as much as 0.10 pH units, even under 100% O-2 ventilation. The inner retinal H+ profile magnitude decreased during occlusion due to impaired clearance. The average outer retinal H+ profile magnitude also increased even though outer retinal H+ production did not increase during occlusion. This might be due to H+ diffusion from the inner retina to the outer retina, which is opposite to the flux in the normal retina. After reperfusion, [H+](o) returned to its preocclusion value.In conclusion, arterial occlusion leads to acidification of the retina. Enhanced oxygenation during occlusion did not decrease this acidification. This may explain why increasing PO2 in the retina by enhanced O-2 breathing improves retinal function during and after occlusion, but does not totally reverse the effect of occlusion. (c) 2004 Elsevier Ltd. All rights reserved.