Wang Yu-Huan, Chen Chao, Shi Wen-Jing, Xiao Hong-Lei, Tong Bei-Yan, Zhou Guo-Min
Department of Neonatology, Children's Hospital, Fudan University, Shanghai 200032, China.
Zhongguo Dang Dai Er Ke Za Zhi. 2006 Apr;8(2):129-32.
This study was designed to investigate the effects of different oxygen inhalation modes on retinal vessels development in neonatal mice in order to provide experimental data for proper oxygen therapy for premature infants.
A total of 144 postnatal day (P) 7 C57BL/6J mice were randomly assigned into 6 groups according to different oxygen inhalation modes (n=24). Experimental group 1 was exposed to 30%, 40%, 50%, 60% and 75% oxygen in turn for one day respectively, followed by room air exposure for 5 days. Experimental group 2 was exposed to 75%, 60%, 50%, 40% and 30% oxygen in turn for one day respectively, followed by room air exposure for 5 days. Experimental group 3 was exposed to 75% oxygen for 5 days, followed by room air exposure for 5 days. Experimental group 4 was exposed to 75% oxygen for 5 days, 50% oxygen for 2 days and 30% oxygen for 2 days, then room air exposure for 6 days. The supplemental 75% oxygen and room air recovering was performed alternately for the mice in Experimental group 5 for 3 times and then room air exposure for 5 days. The Control group was exposed to room air for consecutive 10 days. The retinal vascular development and proliferation were evaluated by the retinal flat-mounts (ADPase stained retina) and cross-section.
The peripheral vascular pattern was clear, and a few avascular areas were seen in the Control group at P12. At P14 the avascular area disappeared. At P17, the entire vascular pattern became completely normal. In the Experimental groups 1, 3 and 5, the central vessels became tortuous and constricted and the central avascular area increased at P12. At P14, neovascularization was seen peaking at P17 in the Experimental groups 1, 3 and 5. In the Experimental group 4, the central avascular area increased and neovascularization was seen at P14, but the central avascular area was reduced and abnormal neovascularization disappeared, with slight constriction of the deep vessels, at P17. Five days later the vascular pattern became almost normal in the Experimental group 4. The retinal vascular form of the Experimental group 2 was similar to that of the Control group. The average number of neovascular nuclei extending into the vitreous per cross-section in the Experimental groups 1, 2, 3, 4, and 5 and the Control group was 49.50 +/- 1.36, 5.17 +/- 0.67, 47.68 +/- 4.70, 5.74 +/- 2.37, 29.15 +/- 2.48, and 1.22 +/- 0.20 respectively. There were significant differences between the Experimental groups 1, 3, 5 and the Control group (P < 0.05).
The effects of different oxygen inhalation modes on the retinal vessels development in neonatal mice were different. The obvious fluctuation of inhaled oxygen concentration and abrupt stop of supplemental oxygen after high levels of supplemental oxygen may severely affect the development of retina vascular, leading to the pathologic changes similar to retinopathy of prematurity.
本研究旨在探讨不同吸氧模式对新生小鼠视网膜血管发育的影响，以便为早产儿适当的氧疗提供实验数据。
将144只出生后第7天（P7）的C57BL/6J小鼠根据不同吸氧模式随机分为6组（n = 24）。实验组1依次分别暴露于30%、40%、50%、60%和75%氧气中各1天，随后暴露于室内空气中5天。实验组2依次分别暴露于75%、60%、50%、40%和30%氧气中各1天，随后暴露于室内空气中5天。实验组3暴露于75%氧气中5天，随后暴露于室内空气中5天。实验组4暴露于75%氧气中5天，50%氧气中2天，30%氧气中2天，然后暴露于室内空气中6天。实验组5的小鼠交替进行75%氧气补充和室内空气恢复3次，然后暴露于室内空气中5天。对照组连续10天暴露于室内空气中。通过视网膜铺片（ADP酶染色视网膜）和横断面评估视网膜血管发育和增殖情况。
对照组在P12时周边血管形态清晰，可见少量无血管区。在P14时无血管区消失。在P17时，整个血管形态完全正常。在实验组1、3和5中，P12时中央血管变得迂曲和狭窄，中央无血管区增加。在P14时，实验组1、3和5中可见新生血管形成，在P17时达到峰值。在实验组4中，P14时中央无血管区增加且可见新生血管形成，但在P17时中央无血管区缩小且异常新生血管消失，深层血管略有狭窄。5天后实验组4的血管形态几乎恢复正常。实验组2的视网膜血管形态与对照组相似。实验组1、2、3、4、5和对照组每横断面延伸至玻璃体的新生血管核的平均数量分别为49.50±1.36、5.17±0.67、47.68±4.70、5.74±2.37、29.15±2.48和1.22±0.20。实验组1、3、5与对照组之间存在显著差异（P < 0.05）。
不同吸氧模式对新生小鼠视网膜血管发育的影响不同。吸入氧浓度的明显波动以及高浓度吸氧后突然停止吸氧可能严重影响视网膜血管发育，导致类似于早产儿视网膜病变的病理变化。
