中华实验眼科杂志
中華實驗眼科雜誌
중화실험안과잡지
CHINESE JOURNAL OF EXPERIMENTAL OPHTHALMOLOGY
2011年
3期
220-225
,共6页
吴小影%罗瑜琳%刘德林%刘双珍
吳小影%囉瑜琳%劉德林%劉雙珍
오소영%라유림%류덕림%류쌍진
左旋多巴%弱视%视觉诱发电位%视皮质%类凋亡
左鏇多巴%弱視%視覺誘髮電位%視皮質%類凋亡
좌선다파%약시%시각유발전위%시피질%류조망
Levodopa%Amblyopia%Visual evoked potential%Visual cortex%Para-apoptosis
背景 对视皮质可塑性的研究目前已有40余年,但至今尚未发现能有效治疗弱视的药物.目的 观察不同剂量左旋多巴对单眼形觉剥夺弱视大鼠视觉诱发电位(VEP)及视皮质神经细胞形态学的影响,探讨左旋多巴治疗弱视的可能机制.方法 2周龄SD大鼠30只眼睑缝合4周建立右眼单眼形觉剥夺性弱视模型后按随机数字表法分成3组,分别以生理盐水、20 mg/kg左旋多巴溶液、80mg/kg左旋多巴溶液灌胃,每日1次.造模4周及给药4周后分别行闪光VEP(F-VEP)检测,给药4周后处死大鼠并取大脑视皮质行苏木精一伊红染色,TUNEL.法观察各组大鼠视皮质神经细胞的凋亡情况.结果 3个组大鼠形觉剥夺模型眼较未剥夺眼P1波隐含时明显延长(P＜0.05),20mg/kg和80mg/kg左旋多巴组剥夺眼给药后较给药前P1波隐含时明显缩短(P＜0.05);3个组间剥夺眼给药前后P1波隐含时及差值比较差异均有统计学意义(P＜0.05).苏木精-伊红染色显示未剥夺眼对侧视皮质V1区神经细胞数量及形态均正常,剥夺眼对侧视皮质神经细胞数量在生理盐水组明显减少,并出现类凋亡表现.20 mg/kg左旋多巴组大鼠视皮质神经细胞数量及形态有轻度改变.TUNEL法示未剥夺眼对侧视皮质呈绿色荧光的阳性神经细胞数为(2.20±1.23)个,生理盐水组、20 mg/kg左旋多巴组、80 mg/kg左旋多巴组剥夺眼相应区域阳性神经细胞数量分别为(53.7±9.36)、(27.20±5.96)、(10.70±3.23)个,提示80 mg/kg左旋多巴组剥夺眼阳性神经细胞数量减少(P＞0.05).给药后各组大鼠剥夺眼对侧视皮质V1区阳性神经细胞数量与F-VEP的P1波隐含时差值呈负相关(r=-0.815,P=0.000).结论左旋多巴可改善形觉剥夺弱视眼的视皮质神经细胞形态和视觉传导功能,其机制可能是通过抑制视皮质神经细胞的类凋亡参与视觉系统的发育和重塑过程.
揹景 對視皮質可塑性的研究目前已有40餘年,但至今尚未髮現能有效治療弱視的藥物.目的 觀察不同劑量左鏇多巴對單眼形覺剝奪弱視大鼠視覺誘髮電位(VEP)及視皮質神經細胞形態學的影響,探討左鏇多巴治療弱視的可能機製.方法 2週齡SD大鼠30隻眼瞼縫閤4週建立右眼單眼形覺剝奪性弱視模型後按隨機數字錶法分成3組,分彆以生理鹽水、20 mg/kg左鏇多巴溶液、80mg/kg左鏇多巴溶液灌胃,每日1次.造模4週及給藥4週後分彆行閃光VEP(F-VEP)檢測,給藥4週後處死大鼠併取大腦視皮質行囌木精一伊紅染色,TUNEL.法觀察各組大鼠視皮質神經細胞的凋亡情況.結果 3箇組大鼠形覺剝奪模型眼較未剝奪眼P1波隱含時明顯延長(P＜0.05),20mg/kg和80mg/kg左鏇多巴組剝奪眼給藥後較給藥前P1波隱含時明顯縮短(P＜0.05);3箇組間剝奪眼給藥前後P1波隱含時及差值比較差異均有統計學意義(P＜0.05).囌木精-伊紅染色顯示未剝奪眼對側視皮質V1區神經細胞數量及形態均正常,剝奪眼對側視皮質神經細胞數量在生理鹽水組明顯減少,併齣現類凋亡錶現.20 mg/kg左鏇多巴組大鼠視皮質神經細胞數量及形態有輕度改變.TUNEL法示未剝奪眼對側視皮質呈綠色熒光的暘性神經細胞數為(2.20±1.23)箇,生理鹽水組、20 mg/kg左鏇多巴組、80 mg/kg左鏇多巴組剝奪眼相應區域暘性神經細胞數量分彆為(53.7±9.36)、(27.20±5.96)、(10.70±3.23)箇,提示80 mg/kg左鏇多巴組剝奪眼暘性神經細胞數量減少(P＞0.05).給藥後各組大鼠剝奪眼對側視皮質V1區暘性神經細胞數量與F-VEP的P1波隱含時差值呈負相關(r=-0.815,P=0.000).結論左鏇多巴可改善形覺剝奪弱視眼的視皮質神經細胞形態和視覺傳導功能,其機製可能是通過抑製視皮質神經細胞的類凋亡參與視覺繫統的髮育和重塑過程.
배경 대시피질가소성적연구목전이유40여년,단지금상미발현능유효치료약시적약물.목적 관찰불동제량좌선다파대단안형각박탈약시대서시각유발전위(VEP)급시피질신경세포형태학적영향,탐토좌선다파치료약시적가능궤제.방법 2주령SD대서30지안검봉합4주건립우안단안형각박탈성약시모형후안수궤수자표법분성3조,분별이생리염수、20 mg/kg좌선다파용액、80mg/kg좌선다파용액관위,매일1차.조모4주급급약4주후분별행섬광VEP(F-VEP)검측,급약4주후처사대서병취대뇌시피질행소목정일이홍염색,TUNEL.법관찰각조대서시피질신경세포적조망정황.결과 3개조대서형각박탈모형안교미박탈안P1파은함시명현연장(P＜0.05),20mg/kg화80mg/kg좌선다파조박탈안급약후교급약전P1파은함시명현축단(P＜0.05);3개조간박탈안급약전후P1파은함시급차치비교차이균유통계학의의(P＜0.05).소목정-이홍염색현시미박탈안대측시피질V1구신경세포수량급형태균정상,박탈안대측시피질신경세포수량재생리염수조명현감소,병출현류조망표현.20 mg/kg좌선다파조대서시피질신경세포수량급형태유경도개변.TUNEL법시미박탈안대측시피질정록색형광적양성신경세포수위(2.20±1.23)개,생리염수조、20 mg/kg좌선다파조、80 mg/kg좌선다파조박탈안상응구역양성신경세포수량분별위(53.7±9.36)、(27.20±5.96)、(10.70±3.23)개,제시80 mg/kg좌선다파조박탈안양성신경세포수량감소(P＞0.05).급약후각조대서박탈안대측시피질V1구양성신경세포수량여F-VEP적P1파은함시차치정부상관(r=-0.815,P=0.000).결론좌선다파가개선형각박탈약시안적시피질신경세포형태화시각전도공능,기궤제가능시통과억제시피질신경세포적류조망삼여시각계통적발육화중소과정.
Background Nearly over 40 years have elapsed since the original findings of visual cortical plasticity,but none of drug has been found for curing amblyopia effectively. Objective The goal of this study was to investigate the effects of different dose of levodopa on flash visual evoked potential(F-VEP)and morphology of visual cortex cells in monocular deprivation rat and explore the possible mechanism of curing amblyopia.Methods Monocular deprivation model were established by suturing eyelids of 30 2-week-old Sprague Dawley(SD)rats for 4 weeks.The 30 SD rats were then divided into 3 groups randomly and 10 rats for each group.Normal saline.20 ms/kg levodopa,80 ms/kg levodopa were intragastrically administered once per day after modeling respectively for 4 weeks.F-VEP was recorded after establishment of model and administration of drug respectively.The rats were sacrificed and the visual cogex was obtained for histological examination,and TUNEL technique was used to assess the structural change of visual cortex.Results The latency of P1 wave was significantly longer in the deprived eye than the normal eyes(P<0.05).After administration of levodopa,the latent periods of Pl wave in the deprived eye were obviously shortened in comparison with before administration of levodopa in 20 ms/kg and 80 mg/kg levodopa group (P<0.05).The difference values of latent period of P1 wave between before and after administration of drug showed statistically significant change in three groups(P<0.05).No evidently alterations were found in the amplitude differences of N1 P1 and P1 N2 waves among three groups(P>0.05).The number and structure of neurons in contralateral visual cortex of non-deprived eye were normal.However,the numbers of neurons in deprived eye were significantly less and presented the signs of para-apoptosis in normal saline group.In 20 mg/kg levodopa groups,the alterations of number and morphology in neurons of rat visual eogex were slight.TUNEL assay revealed that the numbers of positive neurons in contralateral visual codex of non-deprived eye were 2.20±1.23.while those in deprived eye were 53.7±9.36,27.20 4±5.96 and 10.70±3.23 in normal saline group,20 mg/kg and 80 mg/kg levodopa group respectively,showing a significant difference among them(P>0.05).After usage of levodopa,the numbers of positive neurons was negatively correlated with the difference value of P,latent period of VEP(r=-0.815,P=0.000).Conclusion Levodopa has a therapeutic effect on rat deprived eye,and its possible mechanism is inhibiting the para-apoptosis of neurons and participating in the development and plasticity of visual system.
