Developmental changes in embryonic enzyme patterns: The effect of oxidative substrates on lactic dehydrogenase in beating chick embryonic heart cell cultures

Developmental Biology

Robert D. Cahn¹ 

[1] Department of Biochemistry, Lagos University Medical School, Lagos, Nigeria

关键词: LDH;    lactic dehydrogenase;    M-LDH;    muscle LDH;    H-LDH;    heart LDH;    L:H;    the ratio of the rate of NADH oxidation by LDH with a high pyruvate concentration (0.1 M) to that with a low pyruvate concentration (0.0111 M);    PDG;    calcium- and magnesium-free buffered salt-glucose solution;    isosaver;    isotonic bovine serum albumin Veronal buffer;    HBSS;    balanced salt solution for beating heart cells;    KCA;    citric acid cycle intermediates;    CoA;    coenzyme A;    OD;    optical density;    Tris;    tris(hydroxymethyl)aminomethane buffer (Sigma Biochemical Company;    St. Louis;    Missouri);    NADH;    reduced nicotinamide adenine dinucleotide;   

DOI  :  10.1016/0012-1606(64)90029-6

学科分类：生物科学（综合）

来源: Academic Press

【 摘 要 】

Duringthedevelopmentofthechickembryo,theLDHpatternoftheheartcellsremainsalmostunchanged,whileintheskeletalmusclecellsthesynthesisofM-LDHsubunitsbeginsatapproximately6–10daysofincubation.Whenplacedincellcultureinmonolayers,heartcellsbegintosynthesizeM-LDHsubunits,andthepatternofLDHwithinthesecellsshiftstocontainmuchmoreM4andM3HLDH.HeartcellsneversynthesizeM-LDHinanysignificantamountsifleftinovo.Citricacidcycleintermediates(KCA)andcoenzymeA(CoA)retardtheappearanceofthisnewlyacquiredsyntheticcapacity.TheLDHpatternseventuallybecomeidenticalwiththepatternsofthecontrols.RaisedpO2(95%O2:5%CO2)retardsM-LDHsynthesis,andundertheseconditionstheheartcells,unlikethecontrols,stablyproduceamuchsmallerproportionofM-LDHsubunits.Damagetothecellsduringdissociationandtrypsinizationleadingto“leaky”cellsmayaccountpartiallyforthealteredLDHpatternsseeninvitro.Itisproposedthatthecitricacidcycleintermediates,coenzymeA,andoxygenoperateatthelevelofthegeneineffectingthesechangesinthesyntheticpatternsoftheheartcellsinculture.

【 授权许可】

Unknown