The effect of a salt water regimen on the development of the salt glands of domestic ducklings☆

[摘要] Commencingonthefourthdayafterhatchingandcontinuingfor2weeks,84experimentalducklingsweregivendrinkingwatercontaining1or1.2%sodiumchloridefor12hoursdailyandfreshtapwaterfortheremainderofeachday;39controlbirdsdrankonlytapwater.Duringthethirddayoftheexperiment,saltglandeffluent,highinsodiumcontent,appearedattheexternalnaresoftheducklings.After5daysofthesaltwatertreatmentthesaltglandsofexperimentalbirdsweighedsignificantlymorethanthoseofthecontrolbirds,whilethebodyweightsoftheexperimentalducklingsincreasedmoreslowlythanthoseofthecontrols.Thesaltwaterregimenevokedarapidincreaseinthesizeofthesecretorycells,anapparentincreaseinthenumberofsecretorycells,anelongationofthesecretorytubules,andanincreaseinthesizeofthesecretorylobules,withconcomitantdilutionoftheconnectivetissue.Histochemicaldifferencesbetweenthesaltglandsofexperimentalandcontrolbirds,evidentbytheendofthethirdday,wereintensifiedduringtheremainderoftheexperiment.Inadditiontotheirrichcomplementofphospholipid,thelargesecretorycellsinthesaltglandsoftheexperimentalbirdscontainedabundantsuccinicdehydrogenaseandcytochromeoxidaseactivity.Smallerbutsimilarcellsintheglandsofcontrolbirdsofthesameageborelittlephospholipidandwereonlyslightlyreactivefortheseenzymes.Inaddition,thesecretorycellsoftheexperimentalbirdsgavemoderatereactionsfornonspecificesterase,monoamineoxidase,andacidphosphatase.Theonsetofthesecretorycompetenceofthesaltglandcoincidedwiththeappearanceofabundantphospholipidandstrongoxidativeenzymeactivityinthesecretorycells.Inthesecretorylobulesofbothexperimentalandcontrolbirds,twodistinctcelltypescouldbedistinguishedbytheirenzymecontent.Theprincipalsecretorycellswereacidophilic;theycontainednoalkalinephosphatase,butaboundedinsuccinicdehydrogenaseandcytochromeoxidase.Theterminalorperipheralcellsattheblindendsofthesecretorytubuleswerebasophilic;theyreactedforalkalinephosphatase,butcontainedlittlesuccinicdehydrogenaseorcytochromeoxidase.Theposition,aswellastherelativelyundifferentiatedstateoftheperipheralcells,suggeststhattheyhaveagenerativefunction.Thepatternofinnervation,revealedbythecholinesterasetechnique,wasmoreelaborateinthesaltglandsofexperimentalbirdsthaninthecontrols.Thisobservation,whencorrelatedwithavailablephysiologicaldata,suggestedthatthesaltwaterregimenmightnotdirectlyinfluencethegrowthanddifferentiationofthesaltglandbutthattheeffectmightbemediatedbythenervoussystem.

[学科分类] 生物科学（综合）