目的探讨早产对sD大鼠视网膜血管形态发育的影响。方法实验研究。将60只受孕的sD雌鼠分为4组:细菌脂多糖诱导早产组(LPS组)、米非司酮诱导早产组(RP组)和剖宫产早产组(CP组),正常生产大鼠为对照组。记录各组幼鼠出生后21d内体重增长情况。在生后4、7、10、14d随机取各组幼鼠右眼进行视网膜铺片,观察血管生长状况。根据出生幼鼠只数不同,在3个早产组内又分为小窝别(每窝产6~8只幼鼠者,即l组)和大窝别(每窝产14~16只幼鼠者,即2组)两个亚组,在出生后4、7、10d每个亚组随机取6只幼鼠的右眼,观察视网膜血管生长情况。计量资料的比较采用t检验,多组计量资料的比较采用方差分析,组问的多重比较采用LSD-t检验。结果LPS组、CP组、RP组幼鼠出生21d内体重均低于对照组,差异有统计学意义(LSD—t检验:P值均〈0.05)。LPS组[(0.47±0.02)%、(0.63±0.04)%]和RP组[(0.49±0.04)%、(0.65±0.04)%]幼鼠生后4d和7d的视网膜血管化比例小于对照组[(0.57±0.04)%、(0.74±0.05)%](LPS组:t4d=6.427,P4d=0.000;t7d=5.111,P7d=0.000;RP组:t4d=4.469,P4d=0.000;t7d=2.491,P7d=0.022);CP组幼鼠生后4、7、10d的视网膜血管化比例[(0.49±0.05)%、(0.61±0.05)%、(0.94±0.03)%]均小于对照组[(0.57±0.04)%、(0.74±0.05)%、(0.97±0.02)%](t4d=4.044,P4d=0.001;t7d=6.011,P7d=0.000;t10d=2.33l,P10d=0.030)。生后14d各组幼鼠视网膜表层血管化均已完成。LPS组内LPS2组幼鼠生后4d和7d的视网膜血管化比例[(0.44±0.02)%、(0.60±0.03)%]小于LPSl组[(0.53±0.04)%、(0.74±0.03)%](t4d=3.852,P4d:0.008;t,d=5.630,P7d=0.001);CP组内CP2组幼鼠生后4d和7d的视网膜血管化比例[(0.43±0.02?
Objective To study the effects of premature birth on the development of rat retinal vasculature. Methods Experimental study. Sixty pregnant Sprague-Dawley rats were divided into four groups: bacterial lipopolysaccharide-induced preterm group (LPS group ) , RU-486 induced preterm group ( RP group) , cesarean section induced preterm group ( CP group) , and the normal delivery rats as the control group. The weight of rats from each group was recorded until postnatal day 21. On postnatal day 4,7,10 and 14 (P4,P7 ,P10 and P14) ,the retina of right eye was dissected and whole-mounted. Each premature group was divided into two subgroups based on the number of rats in each litter, the small subgroup (6-8 rats per litter, group 1 ) and the large subgroup ( 14-18 rats per litter, group 2 ) . The development of retinal vascularization process was observed on P4, P7 and P10 (n : 6). Independent t test, one-way ANOVA and LSD-t test were used to analyzed the results. Results The weight of premature rats in LPS, CP and RPgroups was significantly lower than that in the normal group within postnatal 21 days (LSD-t test: all P 〈 0. 05). On the P4 and P7 in LPS group, the proportions of retinal superficial vascularized area of newborn rats [ (0.47 ± 0. 02) % , (0. 63 ± O. 04) % ] were less than that in the normal group [ ( 0. 57 ± 0. 04) % , ( 0. 74 ± 0. 05 ) % ] ( t4d = 6. 427, P4 a = 0. 000 ; t7 d = 5.111, P7,1 - 0. 000). On the p4 and P7 in RP group, this proportions [ (0. 49 ± 0. 04) %, (0. 65 ± 0.04) % ] were less than that in the normal group [ (0. 57 ± 0. 04)%, (0. 74 ±0. 05)% ] (t4 d =4. 469 ,P4 d =0. 000;t7 d =2. 491 ,P7 d =0. 022). On P4,P7 and P10 in CP group, this proportions [ ( 0. 49 ± 0. 05 ) %, (0. 61 ± 0. 05 ) % , (0. 94 ± 0. 03 ) % ] were also less than that in the normal group [ ( 0. 57 ± 0. 04 ) %, ( 0. 74 ± 0.05 ) % , ( 0. 97 ± 0.02 ) % ] ( t4 d = 4. 044, P4 d = 0. 001 ; t7 d= 6. 011, P7 d =