Growth, mitosis and morphogenesis of the simple liver acinus in neonatal rats☆
[摘要] Radioautographyafter3H-thymidineinjection,blockageofmitosisduetocolchicineandcameralucidadrawingswereusedtostudygrowth,mitosisandmorphogenesisinthesimpleliveracinusofRappaportinneonatalrats.Hepaticparenchymalcellplatesareirregularlyarrangedandthickfrombirthto4dayspostpartum.By10daystheplatesbegintoassumetheadultconfiguration,irregularandthickinacinarzone1(periportal)butstraightandthininacinarzone3(pericentral).Afterasingleinjectionof3H-thymidineatbirththedistributionoflabelednucleiamongthehepaticacinarzoneswassuchthatzone1containedmost,zone3least,andzone2anintermediateamount.Thisrelationshipremainedconstantoutto10dayspostpartum.Theamountoflabeledcellswithineachzonevaried,reachingitshighestvaluesat2daysinzones1and2butnotuntil4daysinzone3.Similartothedistributionoflabelednuclei,frequencyofmitosisalsoexhibitedaconstantrelationshipofzone1>zone2>zone3,butpeaksofcelldivisionwithineachzonewerenotalwayspresent.Allthreezonesdisplayedapeakofmitosisat4days,whereasasecondmitoticpeakat10dayswasattainedonlybycellsinzones1and2.Conclusionsare:(1)Theneonatalliverisanexpandingcellpopulationwithmostoftheexpansionconfinedtoacinarzones1and2,(2)theperiodof4–6dayspostpartumiscriticalandcouldbethetimewhenacinarmetaboliczonesareforming,(3)theirregulararrangementofcellplatesinthecenteroftheacinus(zone1)mayacttodampenarterialpulsationsandallowadequatemixingofarterialandvenousblood,(4)immediatepostnatalgrowthoftheliveracinus,asshownbyanincreaseinitswidth,isdueprimarilytoanincreaseincellnumbersinceindividualcellsizedoesnotincrease.
[发布日期] [发布机构]
[效力级别] [学科分类] 生物科学（综合）
[关键词] [时效性]
