CAJ | 학술논문

目的：观察N-甲基-N-亚硝基脲( MNU)诱导的大鼠视网膜光感受器损伤过程中Rhodopsin 和recoverin表达变化与损伤的时效关系。 　　方法：将36只SPF级7周龄大鼠随机分为正常对照组, MNU模型组(6h组,12h组,24h组,3d组,7d组),每组各6只。模型组一次性腹腔注射60mg/kg MNU,正常对照组腹腔注射等量PBS。右眼行HE,TUNEL,透射电镜评估视网膜组织损伤的超微结构变化及细胞凋亡程度,左眼取视网膜组织通过Western blot和免疫荧光观察视网膜组织中Rhodopsin和recoverin的mRNA表达变化。 　　结果：透射电镜观察到MNU注射12 h 后出现凋亡小体,24 h后外核层大部分细胞呈阳性反应；TUNEL 检测发现MNU注射24 h 光感受器细胞凋亡指数最高,达(29.7±2.3)%,与电镜结果吻合。 Western blot 结果表明, MNU注射12 h后表达有极显著性差异( P<0.01),而Recoverin的表达从注射后24h有极显著性差异(P<0.01)。 　　结论：一次性腹腔注射60 mg/kg MNU能特异性诱导SD大鼠视网膜光感受器细胞凋亡, Rhodopsin和recoverin表达下调与MNU诱导光感受器细胞的选择性凋亡有关。
목적：관찰N-갑기-N-아초기뇨( MNU)유도적대서시망막광감수기손상과정중Rhodopsin 화recoverin표체변화여손상적시효관계。 　　방법：장36지SPF급7주령대서수궤분위정상대조조, MNU모형조(6h조,12h조,24h조,3d조,7d조),매조각6지。모형조일차성복강주사60mg/kg MNU,정상대조조복강주사등량PBS。우안행HE,TUNEL,투사전경평고시망막조직손상적초미결구변화급세포조망정도,좌안취시망막조직통과Western blot화면역형광관찰시망막조직중Rhodopsin화recoverin적mRNA표체변화。 　　결과：투사전경관찰도MNU주사12 h 후출현조망소체,24 h후외핵층대부분세포정양성반응；TUNEL 검측발현MNU주사24 h 광감수기세포조망지수최고,체(29.7±2.3)%,여전경결과문합。 Western blot 결과표명, MNU주사12 h후표체유겁현저성차이( P<0.01),이Recoverin적표체종주사후24h유겁현저성차이(P<0.01)。 　　결론：일차성복강주사60 mg/kg MNU능특이성유도SD대서시망막광감수기세포조망, Rhodopsin화recoverin표체하조여MNU유도광감수기세포적선택성조망유관。
AIM: To investigate the time - effect relationship between the expression of rhodopsin and recoverin and photoreceptor damage induced by N - nethl - N -nitrosourea ( MNU) . METHODS: Thirty-six 7-week old Sprague-Dawley ( SD ) rats were intraperitoneally injected with MNU ( 60mg/kg ) and were put to death by dislocation of cervical vertebra 6, 12, 24h; 3, 7d after injection ( 6 per group) , respectively. As a control, six rats were injected with phosphate buffer saline (PBS) 5mL/kg and sacrificed on d3 after injection. The degree of photoreceptor apoptosis was detected by HE staining, terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling ( TUNEL ) and transmission electron microscope ( TEM ) in the right eyes. The mRNA expressions of rhodopsin and recoverin were detected different time after injection by Western blot and immunohistochemical method in the left eyes. RESULTS:The dissolution of photoreceptor nucleus and apoptosis body were first perceived at 12h by TEM; most of cells at outer nuclear layer were presented positive reaction. The apoptotic index reached peak ( 29. 7% ±2.3%) at 24h which was coincided with the observation of TEM. The results of immunohistochemistry displayed that rhodopsin and recoverin were on a declining curve with time extension. Furthermore, the results of Western blot indicated that rhodopsin had dramatic decline at 6h after injection (P<0. 05), and extremely significant difference comparing to control group after 12h ( P<0. 01 ); while recoverin dramatic declined at 12h, and extremely significant difference after 24h (P<0. 01). CONCLUSION:60mg/kg MNU intraperitoneally injection one - time may specifically induce photoreceptor apoptosis, The mechanism of down - regulation of rhodopsin and recoverin may be related to the selected apoptosis of photoreceptors.