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“相对缺氧”对早产小鼠视网膜血管影响的研究
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“相对缺氧”对早产小鼠视网膜血管影响的研究

 

赵璐晴  何亚农*  赵跃龙

(中南大学湘雅医学院,湖南 长沙 410013 )

 

摘 要  目的 研究“相对缺氧”理论对早产小鼠视网膜血管的影响及损伤程度。方法 选择88只早产小鼠和8只足月的新生小鼠,分为先潜组、高氧组和空气组,通过观察早产小鼠视网膜新生血管的形成发育状况及其对视网膜产生的损伤程度,来探讨如何进一步减小损伤。结果 高氧组1组:视网膜血管极其扩张、迂曲,结构及分布十分紊乱。随着组数的增加,视网膜血管结构越接近正常。从第8组开始,视网膜血管管径、分支、走行基本正常。同时,视网膜血管内皮细胞核数也从1组的11.2 3.5, 至8组的1.2 1.0,与空气组的正常值1.2 1.1,越来越接近。结论“相对缺氧”对早产小鼠视网膜血管产生的损伤程度与其速度密切相关,速度越快,对视网膜血管的损伤越大;而当速度小于或等于8.75%/天时,吸高浓度氧,对早产小鼠视网膜血管的损伤最小。

关键词 相对缺氧;早产小鼠;视网膜血管;损伤

中图分类号:Q93         文献标识码:A

 

Research on how “relatively lack of oxygen ” affects the retinal blood vessels of the premature mice

 

ZHAO Lu-qing,  HE Ya-nong,  ZHAO Yue-long

( Xiangya medical school, Central South University, Changsha Hunan 410013, P.R. China )

 

Abstract:[Objective]To study how the theory of  “Relatively lack of oxygen” affects the retinal blood vessels of the premature mice and its injuries. [Methods] 88 premature mice and 8 infant mice were divided into three groups: the fore group, the normal oxygen group, and the high oxygen group. During the experiment, the developments and injuries of the neovascularization were observed . Also,the methods of how to reduce the injuries of the retinal blood vessels were discussed. [Results] Group 1 of the high oxygen groups: the retinal blood vessels were extremely expanded and winding. Its structures and distributions were also disordered. However, as the groups increased, the structures of the retinal blood vessels were close to normal. From group 8, the diameters, the branches, and the distributions of the retinal blood vessels returned to normal. At the same time, the number of new vascular cell nuclei changed from group 1: 11.2 3.5, to group 8: 1.2 1.0, which were close to the normal oxygen group: 1.2 1.1. [Conclusion] The injured degree of the retinal blood vessels, caused by “ Relatively lack of oxygen”, has a close relationship with its velocity. The more quickly does the velocity change, the more injuries does it make. However, when the velocity is no more than 8.75% per day, the injuries made on the retinal blood vessels will be the smallest.

 Key words: Relatively lack of oxygen; premature mice ; retinal blood vessels; injuries

 

随着现代医学的发展,早产儿的存活率逐渐提高;但在存活的早产儿中,发生早产儿视网膜病变(Retinopathy of prematurity,以下简称 ROP)的比率也在逐年上升;ROP的发病因素很多,一般认为它们与各种高氧因素、氧自由基的毒性作用、维生素E的缺乏、糖尿病、胎龄、体重等都有一定的关系。然而最新理论认为ROP也与“相对缺氧”关系密切,即:早产儿出生后由于肺部疾病需要吸入氧气治疗,但早产儿的视网膜血管尚未发育完全,从而对氧极为敏感, 高浓度氧(约80%)可使视网膜血管收缩, 使正常的视网膜血管发育停止;当恢复到正常氧浓度(约20%)时,产生了一个氧浓度差,随着代谢需要的增加,大片视网膜无血管区处于组织“相对缺氧”状态;由于缺氧而促使视网膜产生血管新生因子,刺激视网膜新生血管形成,但此新生血管为畸形血管,易发生扩张、弯曲、渗出、出血,最后发生机化形成瘢痕,瘢痕组织的收缩将牵引性视网膜剥离,最终导致失明。本实验的目的是希望通过对早产小鼠吸氧后,控制“相对缺氧”速度的变化,来观察在不同速度下小鼠视网膜新生血管的发育程度及其造成的损伤程度,从而进一步研究如何来减小早产儿的视网膜血管在“相对缺氧”情况下造成的损伤[ 1 ]。

 

1   材料和方法

1.1 实验动物及分组

在动物中心购买孕龄为17天的怀孕母鼠18只(正常母鼠的怀孕周期为20天),进行剖宫产取出早产小鼠,挑选出88只身体状况良好的早产小鼠,并做好标记。再由动物中心购买8只足月的身体状况良好新生小鼠。将所有小鼠(早产、正常)与哺乳母鼠共同饲养一周,使小鼠发育成熟。然后,将标记的早产小鼠取出,置于高浓度氧箱中,吸高浓度氧(80%)3天,再随机分为:高氧组(10组,每组8只);先潜组(1组,8只)。正常的8只新生小鼠,组成对照组(空气组),放在空气中(氧浓度约为20%)做同等条件下的相应的培养。即:在同等实验条件下,高氧组:吸80% O2 3d;先潜组:吸80% O2 ×3d; 空气组:吸空气(20% O2) 3d。

 

1.2 实验过程

    第一步:对先潜组的8只小鼠,任取4只的8只眼,采用视网膜铺片法,观察视网膜血管形态学改变。

第二步:高氧组10组,吸80% O2 3d; 空气组1组,吸空气(20% O2) 3d,对高氧组和空气组的操作如下表1所示:

 

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