Glucose metabolism and chick neurogenesis: I. Glucose-6-phosphate dehydrogenase activity in the embryonic brachial spinal cord☆☆☆

[摘要] Microquantitativeprocedureswereemployedfortheassayofglucose-6-phosphatedehydrogenaseactivityinthedevelopingchickspinalcord.Individualbrachialcordhomogenatepreparations(4.5daysincubationthroughhatching)maintainedarelativelyhighlevelofenzymaticactivitythrough6.5days(stage30)withanapparentpeakat4.75days(stage26).AmarkeddropinlevelofG6DHactivitywasobservedduringtheeighthday(thelevelofactivityforstage33wasonly27%thatofstage30).Thislowlevelofactivitywasmaintainedthroughouttheremainderofdevelopment.Discreteareasofthedevelopingspinalcordwereassayedseparately:littledifferencewasnotedbetweenalarandbasalhalves;however,enzymeactivityinthemantlewasconsistentlyhigherthanintheneuralepithelium.ComplexfluctuationpatternswereobservedforthecephalocaudaldistributionofG6DHactivityinindividualspinalcords;ameaningfulinterpretationofthesepatternsawaitsfurtherinvestigation.TemporalchangesinG6DHactivity(wholecordandsubdivisionsthereof)arediscussedinrelationtoproliferationandcytodifferentiation.TheresultsofthisstudysupportanearlierpostulateofBurtandWenger(1961)andsuggestthatpentosecycleactivityisassociatedwithbothmitosisandearlyneuroblasticdifferentiation.

[学科分类] 生物科学（综合）