Development of the rat salivary glands: IV. Amylase and ribonuclease activity during embryonic and neonatal development of the parotid and submaxillary glands☆☆☆

[摘要] Amylaseandribonucleaseactivityweremeasuredintheparotidandsubmaxillaryglandsoftheratoverthecourseoftheirdevelopmentinvivo.Intheparotid,amylasespecificactivityincreasesfromalmostundetectablelevelsinthe16-dayembryonicrudiment,toafivefoldhigherplateaubetween18daysandbirth,andthenincreasestoanadultlevelwhichis5000-foldhigher.RNAaseactivityincreaseseightfoldfrom15dayspostconceptionto7dayspostpartumandthenbeginsamorerapidincreasetoa20-foldhigheradultlevel.Intheembryonicsubmaxillarygland,bothenzymesincreasemorethan15-foldtoreachmaximallevelsinthefewdaysfollowingbirth.Inthecourseofpostnataldevelopment,theseactivitiesarelost,andintheadulthavedecreasedtothelowlevelsthathadbeenpresentintheearlyembryonicrudiments.MeasurementsofRNAaseandamylaseactivityinanonsalivaryepithelium,thelung,alsoshowedanembryonicincreaseinenzymeactivity.Therefore,attributingtheembryonicincreasesinthesalivaryenzymestocell-specificmechanismsisspeculative,andtheevaluationoftheirdevelopmentalsignificancedependsonthequalitativeidentificationofthedifferentenzymeproteins.

[学科分类] 生物科学（综合）