The effect of hydrocortisone on exportable enzyme accumulation in the differentiating chick pancreas☆
[摘要] Developmentalpatternsofaccumulationofchymotrypsinogen,procarboxypeptidaseA,amylase,andendonucleaseintheembryonicchickpancreaswerecompared.Theenzymesstudiedseemtofallintotwoclasses:(1)those,likeamylaseandprocarboxypeptidase,whichstarttoaccumulaterapidlyatearlystagesofdevelopmentandwhichaccumulateintwosteps;and(2)those,likechymotrypsinogenandendonuclease,whichaccumulateslowlyduringearlydevelopment(before14days)andrapidlythereafterinasinglestep.Hydrocortisone(hemisuccinate)injectionat10and12daysofdevelopmentcausesaprecociousincreaseinthelevelsofamylase,procarboxypeptidaseA,chymotrypsinogen,and,toalesserextent,endonuclease.Thelevelsofchymotrypsinogenandendonucleaseincreaseduringthefirstdayafterhydrocortisoneinjection,whereasthelevelsofamylaseandprocarboxypeptidaseAareelevatedonlyafteralagofatleastaday.Effectsofhydrocortisoneinjectiononacinarcellultrastructurewerealsoinvestigated.Injectionofthehormoneprematurelyinducedarapidproliferationoftheroughendoplasmicreticulumandasharpincreaseinthenumberandsizeofzymogengranules.Thedatasupportthehypothesisthattheexocrinechickpancreasdifferentiatesintwophases,anearlyphaseandamaturationphaseandthatthelatterphaseisinitiatedbyadrenalcorticalsteroidssecretedbytheembryo.
[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]
