Inhibitory effects of dibutyryl cyclic AMP and theophylline on the melanosome transformation in the embryonic chick pigmented retina cultured in vitro

[摘要] Whentheretinalpigmentepithelialcellsofchickembryoareculturedinmonolayerconditions,thepigmentgranulesarelostfromthecytoplasm.Thefirststructuralchangeindepigmentationisthetransformationofpigmentgranulesintothedegradativeorganellesdesignatedasthedensebodyandmelanosomecomplex.ThecellsaregrowninmediumcontainingDBcAMPofvariousdosesfrom10−5to10−2M.CellproliferationisretardedbytreatmentwithDBcAMP(10−3M).Thetransformationofpigmentgranulesisalmostcompletelypreventedinall1-dayculturedcells.In5-dayculturedcellscontinuouslytreatedwithmorethan10−4M,thetransformationisnotonlyprevented,butthesynthesisofpigmentgranulesisstimulated.Asimilarresultisobtainedbytheadministrationof10−3Mtheophylline.5′-AMPdoesnotpreventthetransformationofpigmentgranulesbutseemstostimulatethesynthesisofpigmentgranules.Ontheotherhand,cGMPisineffectivebothonpreventionoftransformationandonsynthesisofpigmentgranules.Themechanismsofthetransformationofpigmentgranulesarediscussed.

[学科分类] 生物科学（综合）