正常和白内障晶体上皮环磷酸腺苷与钙－钙调蛋白的研究

AstudyoncAMPandCa┐CaMoftheepitheliuminhumannormalandcataractouslenses

目的探讨晶体上皮钙－钙调蛋白（ｃａｌｃｉｕｍ－ｃａｌｍｏｄｕｌｉｎ，Ｃａ－ＣａＭ）与环磷酸腺苷（ｃｙｃｌｉｃａｄｅｎｏｓｉｎｅｍｏｎｏｐｈｏｓｐｈａｔｅ，ｃＡＭＰ）信使系统的关系以及可能的致白内障作用。方法采用酶促和放射免疫法，测定正常人和白内障晶体上皮ｃＡＭＰ、Ｃａ和ＣａＭ的含量。结果发现老年性白内障晶体上皮ｃＡＭＰ含量下降、Ｃａ－ＣａＭ含量升高。结论Ｃａ的升高是白内障形成的重要原因，ＣａＭ则“放大”了Ｃａ的作用，而ｃＡＭＰ含量降低可能使Ｃａ含量进一步升高。

ObjectiveThestudywasdesignedtostudytherelationshipbetweencalcium-calmodulin(Ca-CaM)andcyclicadenosinemonophosphate(cAMP)systemsandtheirpossiblecataractogenicefects.MethodsWemeasuredcAMP,CaandCa-CaMintheepitheliumofhumannormalandcataractouslensesbyenzymicandradioimmunoassaymethods.ResultsThelevelsofCa-CaMintheepitheliumofsenilecataractouslenswerehigher,whileofcAMPwerelowerthanthatinthenormallens.ConclusionTheresultsimplythatthelowlevelofcAMPmightcausethehighlevelofcalciuminthelenswhichispossiblyacataractogenicfactor.Thedangerousroleofcalci-umisamplifiedbytheelevationofCa-CaM.