发育期单眼形觉剥夺弱视模型猫视皮层谷氨酸受体状况的研究

目的 观察单眼形觉剥夺性弱视动物模型谷氨酸受体(GluRs)的变化,探索形觉剥夺性弱视发生的物质基础.方法 11只初生家养猫随机分为两组,处理组在3周龄时缝合单侧眼睑塑造单眼形觉剥夺性弱视模型,3月后用受体的放射性配体结合分析实验观测视皮层GluRs的结合位点数和亲和力.对照组未予特殊处理.结果 处理组视皮层GluRs结合位点数较对照组下降(P＜0.001),而KD值高于对照组(P＜0.001).两组放射性配体-受体结合实验的Hill系数均接近于1.L-3,4-~3H]-谷氨酸与各型GluRs结合位点的亲和力相同,无正负协同效应.结论 单眼形觉剥夺性弱视动物模型视皮层GluRs亲和力低,GluRs参数出现异常,说明形觉剥夺性弱视的发生可能有一定的物质基础.

Effcts of Monocoular Visual Deprivation on Paramenters of GLuRs in Visual Cortex in Deveping Kittens

Objective To explore the molecular mechanism of the development of amplyopia.Methods Lid suture was performed on 5 kittens at 3 weeks of age to produce monocular visual deprivation.Six kittens were used as controls without any treatment.Three months later,the characteristics of3,4-~3H]1-glutamate binding to the visual cortical membranes of the kittens were studied using radiolabelled ligand receptor binding assay.Results The kittens with monocular deprivation had decreased GluRs binding sites in the visual cortex as compared with the controls(P＜0.001).The kittens with monocular deprivation had greater value of KD than the controls(P＜0.001),indicating a decrease in the affinity of GluRs.The Hill coefficients of all of the kittens were close to 1,indicating that3,4-~3H]1-glutamate binded to a single-site receptor,obeying mass action law.Even if there were multi binding sites in GluRs,the affinify of these sites to3,4-~3H]1-glutamate was almost identical.Neither positive nor negative interactive effects existed.Conclusion Monocular deprivation does affect the binding parameters(KD and B_(max))of GluRs,which may be a molecular mechanism of the development of amblyopia.