Insulin accelerates the development of intestinal brush border hydrolytic activities of suckling mice☆

[摘要] Theinfluenceofinsulinonthepostnataldevelopmentofintestinalbrushbordermembranedisaccharidase(sucrase,maltase,trehalase,lactase)andpeptidase(leucylnaphthylamidase,γ-glutamyltranspeptidase)activitieshasbeenstudiedinmice.At8daysofage,theanimalsreceivedeither5,10,or12.5mUinsulin/gbodywt/dayduring3days.Aprematureappearanceofsucraseactivitywasnoted,thelevelofsucraseactivitybeingdependentoftheamountofinsulininjected.Maltaseandlactaseactivitieswerebothincreasedwhiletrehalaseactivitywasaffectedonlybythehighestdoseofinsulin.Thebehaviorofthetwopeptidaseswasquitedifferentasγ-glutamyltranspeptidasewasprematurelyincreasedandleucylnaphthylamidasewasunaffectedbyinsulin.Thehormonaleffectisexertedalongtheentiresmallintestine.Thetimecourseoftheresponsesofthedisaccharidasesinrelationshiptocellularmigrationalongthecrypt-villusaxishasalsobeenstudied.By24hrafteradministrationofasingleinjectionof12.5mUinsulin/gbodywt,sucraseactivitywasalreadypresentandanincreasedmaltaseandtrehalaseactivitieswereobserved.Duringthesubsequent72hrnofurtherincreaseofenzymaticactivitywasnotedeventhoughtheepithelialcellsaremovinguponthevilliatafasterratethanincontrols,thusindicatingthatthereisnorelationshipbetweentheenzymaticresponsesandthecellularmigration.Thepresentdatashowthataprematureincreaseofthecirculatinglevelofinsulininfluencesthedevelopmentofintestinalmucosainsucklingmouse.

[学科分类] 生物科学（综合）