The Relationship Between Metallothionein And Rat Radiation Cataract

Purpose:The use of animal experiments, through the one-time dose X-ray (25Gy) irradiationSD rat eyes to set up animal model of radiation cataract. After irradiation, to observe thesituation of the rats’ lens at one, two, four weeks. and to detect the level of themetallothionein in the lens. Investigate the relationship between metallothionein and ratradiation cataract.Method:Before irradiation, Select8rats as normal control group. experimental irradiationgroup is24rats, the one-time dose X-ray (25Gy) irradiation SD rat eye(two eyes together).After irradiation, all rats were anesthetized by intraperitoneal injection of3.6%chloralhydrate, and used tropicamide card amine eye drops to fully mydriasis, slit lampmicroscope observed the opacity of the lens in the one, two, four weeks and recorded theirsituations respectively, Then randomly8rats selected from experimental irradiation groupwere sacrificed in the above-mentioned point in time and removed their lens. Respectively,using reverse transcriptase polymerase chain reaction (RT-PCR), and Western blot method(Western blotting) to detect MT-I、MT-II mRNA and metallothionein protein (MT)expression in the above-mentioned point in time on the rat lens.Application SPSS17.0statistical software for statistical analysis, the independent theSamples T-Test Method and One-Way-ANOVA method respectively was usedindependent samples T-test and ANOVA analysis of measurement data, using the LSDmethod comparison between groups.Result:First. Morphology: the one-time dose X-ray (25Gy)irradiation SD rat eyes, afterirradiation, using the mydriasis to observe the rat lens no turbidity before two weeks. but inthe fourth week after irradiation the posterior capsule and cortex began to appear small,scattered white spots like opacities. Second. RT-PCR results: there is the expression of the MT-I、MT-II in the rat lens atthe mRNA level. the experimental group and control group of the lens by RT-PCR will beeligible for the MT-I、MT-II positive target gene. The lens of the experimental group, MT-I、MT-II mRNA expression compared with the normal control group to have increased invarying degrees, The difference was statistically significant (P <0.05). And with theextension of time after irradiation, the above time points MT-I、MT-II mRNA expressionshowed a first increased then decreased trend, each time point of change are different, thedifference was statistically significant (P <0.05).Third. Western blotting results: The experimental irradiation group metallothioneincontent relative to the normal control group increased, the difference was statisticallysignificant (P<0.05). Experimental irradiation group metallothionein content wasdecreased after the first increase with the extension of the exposure time, and the change ispresence among the above-mentioned time, the difference was statistically significant (P<0.05).Conclusion:A one-time large dose of X-ray(25Gy) irradiated rat eyes in a short period of time cancause crystals turbid; it can improve MT-I、MT-II mRNA and metallothionein content andexpression level. when the expression of MT decline, The crystals appear turbid, the casemay indicate that MT participate in radiation cataract formation.