| PrefaceAfter cataract is one of the most frequent complications after cataract surgery. It has been confirmed that the proliferation, migration and differentiation of lens epithelial cells ( LECs) are the important machanism of development of after cataract. How to inhibit the proliferation of LECs and decrease PCO are always study focus. Reseachers tried to clear out residue LECs and inhibit mitosis to postpone the process of after cararact, which has attained progress to some extent but was unsatisfied. In recent years, it has showed that gap junction played important effect on the proliferation of hepatic cells and tumor cells. It is also proved that one third to half of surface of LECs was occupied by gap junctions, which was higher than that of any other body cells. In addition, lens is an avas-cular tissue so it is believed that gap junction played key role on maintaining materials communication and metabolism homeostasis. Thus whether gap junction played the same important effect on the proliferation of LECs is a topic deserved to study and explore.Gap junction is a special structure in cell membrane composed by connexon between cells, which can pass ion, micromolecule, metabolic product and second massenger and form metabolism couple and galvanic couple. Now, it has been found that gap junctions exist in all cells but ripe somatic muscles and blood cell, which are especially abundant in tumor cells, cardiac muscle cell and proliferating hepatic cells. Abundant gap junctions also exist in lens cells surface, which make lens cells become a functional syncytium that all cells can enjoy ion, second massenger and metabolic product to maintain osmotic pressure, metabolism homeostasis in lens and lens transparent. Therefore, expres-sion abnormity of gap junction necessarily induced changes of morphous and function of lens. Connexin is the main composition of gap junction and connexin in lens is mainly Cx43xCx46%Cx50 etc. Recent study has showed that borderline between epithelium and fiber , anterior pole and equator region in lens mainly expressed Cx43 protein.Our study assayed changes of Cx43 expression during different periods after phacoemulsification to explore the relative between Cx43 and PCNA (proliferating cell nuclear antigen) and summerize the change law in the precess of lens proliferation after phacoemulsification, which can establish rationale to elucidate the development machanism of after cataract and provide strong experimental foundation to selectively regulate Cx43 to prevent after cataract.Methods30 rabbits in test group anesthetized by anesthetic drug (0.2ml/kg) were operated phacoemulsification by the same surgeon. Limbus corneae was cut in depth and with the length of 3. 2mm. Hellon was infused into anterior chamber. The anterior capsular of lens was torn ring - shaped with 4mm diameter. Sub-capsular cortex was seperated by water. The content in lens was absorbed at I/U level and the posterior capsular was integrated. The cut was not suture. The eyes suffered surgery were sub - conjunctival injection with cidomycin and hexa-decadrol. And the pupils were dilated by 1% atropine , which was operated at the NO. 1,2,3 day after surgery. 3 rabbits were killed at the NO. 1,2,3,4,5,6, 7,14,30,90 day respectively after operation and lens were extirpated for test. Rabbits in control group without any treatment were also killed and lens were extirpated for test. Residue lens capsular and integrated lens were extirpated with sterile operation under operating microscope. 6 lens of 3 rabbits in each group (66 in all) were immediately fixed by 10% formalin and embedded by paraffin wax. Each slides was 4jxm , which was prepared for HE staining and immuno-histochemistry assay.Results1. Results of rabbits' eyes observation after operationAt the NO. 1 day after operation, there were corneal edema and obvious cellulose exfiltration in anterior chamber. At the NO. 7 day after operation, corneal edema and cellulose exfiltration disappeared and the posterior capsular was not opacity. At the NO. 14 day after operation, the perimeter of posterior capsular appeared opacity. At the NO. 30 day after operation, there were slight opacity in posterior capsular. At the NO. 90 day after operation, there was mass -shaped cellulose exfiltration in anterior chamber.2. Results of HE staining of lens after operationLECs in subcapsular of anterior capsule and equator in normal control group were monolayer, the nucleus was round. There was no cell in subcapsular of posterior capsule. At the NO. 1 day after operation, the monolayer cell nucleus in subcapsular of anterior capsule was oval; cells in equator became multilayer, which differentiated to lens fiber and moved to posterior capsule. At the NO. 7 day after operation, cells in equator remained multilayer, cells that moved to posterior capsule appeard in a way of cluster, a great deal of lens fiber that arranged in order could be seen. At the NO. 30 day after operation, cells in equator came back to monolayer, cells in posterior capsule became fibrosis. At the NO. 90 day after operation , cells in equator were monolayer, a great deal of fiber appeared.3. Results of immunohistochemistry assay of Cx43 in LECs after phacoe-mulsificationPositive cells of Cx43 showed cytoplasm and cellular membrane were stained brown - yellow. The positive expression of Cx43 in equator and anterior capsule increased dramaticly, compared with that of the control group and the A value hit the peak at the NO. 3 day after operation (A value was 0.49 ±0.03 and 0. 42 ±0.04 respectively). The positive expression of Cx43 decreased obviously at the NO. 7 day after operation ( A value was 0. 37 ± 0. 03 and 0. 29 ± 0. 03respectively) and kept level with that of the control group at the NO. 3 day af-...
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