兔角膜穿通伤愈合过程中角膜强度的变化及keratocan的表达  

Corneal strength change and keratocan expression of corneas during the healing of penetrating injury in rabbits

作　　者：刘金玲[1] 连玲艳[1] 刘欢[1] 张晓融[1] 

机构地区：[1]河北医科大学第三医院眼科,石家庄050051

出　　处：《中华实验眼科杂志》2015年第7期611-615,共5页Chinese Journal Of Experimental Ophthalmology

基　　金：河北省科技厅支撑项目（11276103D-20）

摘　　要：背景 角膜穿通伤缝合术后的角膜白斑是角膜伤口过度愈合的结果,控制角膜创伤或手术后过度的愈合反应,抑制瘢痕过度增生是角膜创伤愈合研究的重点. 目的 研究兔角膜穿通伤缝合术后不同时间点的角膜强度和角膜基质细胞标志物keratocan的变化及二者间的关系,确定角膜缝线拆除最佳时机.方法 选择6月龄新西兰大白兔80只,于角膜中央区沿垂直径作一长约5 mm的全层切口,然后用10-0尼龙缝线间断缝合伤口3针,制作兔角膜中央穿通伤缝合术模型.分别于术后1、2、3、4、5、6、7、8周任意处死4只实验兔并摘除实验眼,取伤口中央区角膜制备长7 mm、宽5 mm的角膜组织试件,在electroforce3220-AT生物力学机上进行单轴拉伸破坏试验,测定角膜穿通伤缝合术后角膜强度.分别于术后1、2、3、4、5、6、7、8周任意处死6只实验兔并摘除实验眼,沿角膜缘分离取完整角膜,采用逆转录PCR（RT-PCR）法检测角膜中keratocan mRNA表达量的动态变化.所有操作严格遵循ARVO对眼科及视觉科学研究动物使用的规定.结果 术后1～6周角膜强度分别为0、（1.007±0.041）、（1.991±0.034）、（2.512±0.030）、（3.630±0.049）和（4.935±0.004） MPa,术后3～6周时角膜强度值均大于相邻的前一时间点值,差异均有统计学意义（q=6.35、7.54、8.21、5.86,均P＜0.01）,6周后兔角膜强度稳定.术后1周角膜中keratocan mRNA即出现高表达,术后1、2、3、4、5、6周角膜中keratocan mRNA表达量（A值）分别为0.869±0.015、0.779 ±0.065、0.621 ±0.027、0.460±0.018、0.393±0.057和0.255±0.045,各时间点keratocan mRNA表达量均低于相邻的前一时间点值,差异均有统计学意义（q=5.24、5.61、7.49、4.75、5.47,均P＜0.01）,6周后角膜中keratocan mRNA表达量趋于稳定.结论 角膜穿通伤术后角膜强度的变化与角膜中keratocan下调有关.兔角膜穿通伤缝合术后6周角膜基质细胞的转化趋�Background Corneal walleye formation is a result of excessive corneal wound healing.Controlling the corneal trauma or excessive healing reaction after operation of penetrating corneal trauma is a focus in the study of corneal wound healing.Objective This study was to investigate the changes of corneal strength and the expression of keratocan,a marker of corneal stroma,after corneal penetrating injury operation,and to determine the optimal removal time of corneal suture.Methods Full-thickness incisions of 5 mm along the vertical diameter were done at the central cornea on 80 eyes of 80 six-month-old New Zealand rabbits in this study.Then the incisions were interruptedly sutured with 10-0 nylon thread to establish the corneal wound healing models.Each 4 rabbits were sacrificed in 1 week,2,3,4,5,6,7,8 weeks after operation,respectively,and the central corneal stripes were prepared with the size of 7 mm＆#215;5 mm.The mean maximal strength of the corneal bands was measured by uniaxial tensile test with electroforce3220-AT biomachanics machine.Then,each 6 whole corneas were obtained at the above time points,and the dynamic changes of keratocan mRNA expression in the specimens were detected by reverse trancription PCR （RT-PCR）.The care and use of the animals followed the rules of ARVO.Results The mean maximal strength of corneal stripes was 0,（1.007 ± 0.041）,（1.991 ± 0.034）,（2.512 ± 0.030）,（3.630 ± 0.049） and （4.935 ± 0.004）M Pa in 1 week,2,3,4,5,6 weeks after modeling,and the corneal strength values from 3 weeks through 6 weeks were significantly enhanced in comparison with the value at the adjacent before timepoint （q =6.35,7.54,8.21,5.86,all at P〈0.01）.The relative expression levels （absorbance） of keratocan mRNA in the corneas were 0.869±0.015,0.779 ± 0.065,0.621 ± 0.027,0.460 ± 0.018,0.393 ± 0.057 and 0.255 ± 0.045 in 1 week,2,3,4,5,6 weeks after operation,and each value was lower than that of the adjacent before timepoint （q =5.24,5.61,7.49,4.75,5.47,all at P〈0.01

关 键 词：眼外伤 角膜/病理生理 生物力学 角膜基质细胞 纤维化 逆转录PCR 

分 类 号：R779.6[医药卫生—眼科]