The effect of hypophysectomy upon cholinesterase activity in the forelimbs of regenerating adult Notophthalmus newts☆

摘要

Inordertostudyendocrineinfluenceuponcholinesteraseactivityduringregeneration,adultnewtswerehypophysectomizedeitherpriortolimbtransectionorduringregeneration.Homogenatesoflimbtissueswereassayedforcholinesteraseactivityduringeachstageofregeneration.Inanimalswithpituitariesintact,cholinesteraseactivityinregeneratinglimbtissuesdecreasessoonafteramputation,andthenitrisestothelevelofactivityinintactlimbsofnormalanimals,duringtheperiodofdifferentiation.Inhypophysectomizednewtsthereseemstobenoalterationofthisbasicpatternofactivity,butremovalofthepituitarydoesresultinmoreelevatedlevelsofenzymaticactivity.Intheintactforelimbsofcontrolnewtsundergoingregeneration,cholinesteraseactivitygreatlyincreasesastheothertransectedlimbbeginstoregeneratebutitreturnstonormalasregenerationprogresses.Iftheseanimalsarehypophysectomized,nosuchincreaseisobservedduringtheearlystagesofregeneration.Rather,thereisaninitialdecreaseincholinesteraseactivitythatisfollowedbyanincreaseinsuchactivity.Thesedataarecompatiblewiththehypothesisthatthepituitarymodulatescholinesteraseactivityinthelimbtissuesofadultnewts.