Synthesis of type IV collagen and laminin in cultures of skeletal muscle cells and their assembly on the surface of myotubes☆

[摘要] Thesynthesisoftwocomponentsofthebasallamina,lamininandtypeIVcollagen,andtheirextracellulardepositiononthesurfaceofmyotubeswasstudiedinculturesofembryonicmouseandquailskeletalmusclecellsandintheratmyoblastcelllineL6.ProductionoftypeIVcollagenandlamininbymyoblastsandmusclefibroblastswasdemonstratedbyincorporationofradioactiveaminoacidsintoproteinsandbyimmunoprecipitationwithspecificantibodiesandelectrophoreticanalysisoflabeledproteins.ImmunofluorescencestainingexperimentsrevealedstrongintracellularreactionswithantibodiestolamininandtypeIVcollageninmononucleatedmyogenicandfibrogeniccells.Cellsoffibroblast-likemorphologyshowedamoreintensestainingthanbipolar,spindle-shapedcellswhichperhapsrepresentedpostmitoticmyoblasts.Myotubesdidnotshowdetectableintracellularstaining.TheformationofabasallaminaonmyotubeswasindicatedbythedepositionoflamininandtypeIVcollagenonthesurfaceofmyotubesasviewedbyimmunofluorescenceexaminationofunfixedcells.Stainingforextracellularlamininwasstrongerinmassculturesthaninmyogenicclones,suggestingthatsecretionanddepositionofcomponentsofthebasallaminaonthemyotubesurfacearecomplexprocesseswhichmayinvolvecooperationbetweenmyogenicandfibrogeniccells.

[学科分类] 生物科学（综合）