[Effects of monocular visual deprivation on parameters of GLuRs in visual cortex in developing 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 of [3,4-3H]-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 affinify of GluRs. The Hill coefficients of all of the kittens were close to 1, indicating that [3,4-3H]1-glutamate binded to a single-site receptor, obeying mass action law. Even if there were multi binding sites in GluRs, the affinity of these sites to [3,4-3H]1-glutamate was almost identical. Neither positive nor negative interactive effects existed. CONCLUSION: Monocular deprivation does affect the binding parameters (KD and Bmax) of GluRs, which may be a molecular mechanism of the development of amblyopia.