Abnormal Retinal Vascular Oxygen Tension Response to Light Flicker in Diabetic Rats
Abnormal Retinal Vascular Oxygen Tension Response to Light Flicker in Diabetic Rats
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DOI：
10.1167/iovs.09-3465
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发表时间：
2009-11-01
影响因子：
4.4
通讯作者：
Shahidi, Mahnaz
中科院分区：
文献类型：
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作者：
Blair, Norman P.;Wanek, Justin M.;Shahidi, Mahnaz
目的。验证糖尿病患者血管内氧对光闪烁反应异常的假设。用链脲佐菌素致糖尿病大鼠10只眼进行观察。在视网膜光学切片图像上无创测量视网膜动静脉的氧张力（PO2）。根据静脉注射卟啉钯分子探针的磷光被氧猝灭来估计PO2。测量在有和没有10hz闪烁的情况下进行。调整动脉ph后计算血氧饱和度（SO2）。在正常大鼠中，闪烁引起动脉PO2升高，动脉和静脉PO2差异（A-V差）分别从51 +/- 5（平均值和标准差）增加到55 +/- 7 mm Hg，从22 +/- 3增加到26 +/- 5 mm Hg （P分别< 0.002和0.015）。闪烁导致动脉SO2和A-V SO2差异分别从64% +/- 8%和34% +/- 4%增加到68% +/- 7%和38% +/- 6% （P分别< 0.002和0.035）。静脉中PO2和SO2未见变化，并伴有闪烁。在糖尿病大鼠中，闪烁诱导的视网膜动脉、静脉中PO2或SO2未见明显变化，也未见A-V差异。糖尿病大鼠没有闪烁引起的动脉血PO2和SO2升高，也没有正常大鼠动脉血PO2和SO2的A-V差异。最好的解释似乎是糖尿病损害了通常由光闪烁引起的氧气消耗的增加。（Invest Ophthalmol Vis Sci. 2009;50:5444-5448） DOI: 10.1167/iovs.09-3465
PURPOSE. To test the hypothesis that the intravascular oxygen response to light flicker is abnormal in diabetes.METHODS. Ten eyes of normal rats and 10 eyes of rats made diabetic with streptozotocin were examined. Oxygen tension (PO2) was measured noninvasively in the retinal arteries and veins on optical section retinal images. PO2 was estimated based on the quenching by oxygen of the phosphorescence of an intravenously injected palladium porphyrin molecular probe. Measurements were conducted with and without light flicker at 10 Hz. Oxygen saturation (SO2) was calculated with adjustment for the arterial pH.RESULTS. In the normal rats flicker induced an increase in arterial PO2 and in the difference in arterial and venous (A-V difference) PO2 from 51 +/- 5 (mean and SD) to 55 +/- 7 mm Hg and from 22 +/- 3 to 26 +/- 5 mm Hg, respectively (P < 0.002 and 0.015, respectively). Flicker induced an increase of arterial SO2 and A-V SO2 difference from 64% +/- 8% to 68% +/- 7% and from 34% +/- 4% to 38% +/- 6%, respectively (P < 0.002 and 0.035, respectively). No changes in PO2 or SO2 were observed with flicker in the veins. In the diabetic rats, no significant flicker-induced changes were seen in PO2 or SO2 in the retinal arteries, veins, or A-V differences.CONCLUSIONS. The diabetic rats lacked the flicker induced increase in arterial PO2 and SO2 and also the A-V difference in PO2 and SO2 observed in the normal rats. The best explanation appeared to be that diabetes impairs the increase in oxygen consumption normally provoked by light flicker. (Invest Ophthalmol Vis Sci. 2009;50:5444-5448) DOI: 10.1167/iovs.09-3465