Ontogeny of gluconeogenesis in the bovine fetus: Influence of maternal dietary energy☆☆☆

[摘要] TheinfluenceofmaternalenergyintakeonthedevelopmentofgluconeogenesiswasstudiedintheliverofthebovinefetusfromDays88to270ofgestation.Fetalliveractivities(unitspergramoftissue)ofcytoplasmicGTP:oxalacetatecarboxy-lyase(transphosphorylating)(PEPCK)andmitochondriall-malate:NAD+oxidoreductase(MDH)increasedlinearlywithincreasinggestationalage.FetalcytoplasmicMDHactivitiesreachedmaternallevelsby120daysofgestation,andfetalmitochondrialpyruvatecarboxylaseapproachedmaternallevelsby200daysofgestation.Fetalactivitiesofmitochondrialandcytoplasmicpropionyl-CoA:carbondioxideligase(ADP-forming)(PCC)didnotchangewithgestationalageandwereabout45and7%,respectively,ofmaternallevels.Fetalactivitiesofmitochondrialandcytoplasmicl-aspartate:2-oxoglutarateaminotransferasewerebothabout24%ofthematernalactivitiesthroughoutgestation.Maternalandfetalliveractivitiesofd-fructose-1,6-diphosphate1-phosphohydrolase(FDP)weresimilaranddidnotchangewithgestationalage.Glucosesynthesisfromlactatebyfetalliverslicesinvitrowasslightlylowerand,fromalanineandaspartate,wasslightlyhigherthanglucosesynthesisbymaternalliverslices.Restrictionofmaternaldietaryenergyintakedidnotsignificantlyaltergluconeogenic-relatedenzymeactivityinvitroinmaternalorfetalliverorinthemetabolismofaspartate,alanine,orlactatetoglucoseorCO2byliverslicesinvitro.Acapacityforgluconeogenesishasbeenmeasuredinthebovinefetusasearlyas88daysofgestation.

[学科分类] 生物科学（综合）