钠离子对仔猪小肠刷状缘膜囊二肽跨膜转运的影响(英文)

为研究Na+在仔猪小肠Gly-Pro跨膜转运中的作用,采用同位素示踪及体外孵育技术,观察在不同Na+浓度梯度条件下Gly-Pro在仔猪小肠刷状缘膜囊(brush border membrane vesicles,BBMV)的跨膜转运量。结果表明:(1)用K+替代Na+,并没有降低Gly-Pro在BBMV中的转运量,在孵育前20min时间

动物营养学报2007,19(3):1932198

ChineseJournalofAnimalNutrition

EffectsofSodiumIononTransportofDipeptideinSmallIntestinalBrushBorderMembraneVesiclesofPiglets

DAIJian2guo　LIDe2fa3　PIAOXiang2shu　CHENHong2liang　WANGChun2lin

(CollegeofAnimalScienceandTechnology,ChinaAgriculturalUniversity,Beijing100094,China)

Abstract:InordertostudythefunctionofsodiumionintransmembranetransportofGly2Proeptideinsmallin2testineofpiglets,radioactiveisotopetraceandinvitrotothetransmem2branetransportofGly2Prodipeptideinsmallintestinalmbrane).Theresultsshowedthat1)transportofGly2Pro++thefirstperiodof20min;

2)Na+concent2ftransport,buthadnoeffectontransportofGly2Pro.HartofsignificantlybuthadnoeffectonGly2Protransport.Itwassugges2tedthattransportinsmallintestinalBBMVofpigletswasindependentonconcentrationgradientofNa+.

Keywords:Sodiumionconcentrationgradient;Piglet;Brushbordermembranevesicle;Dipeptide;Transport

　　Purifieddietsorbalancedaminoaciddiets

withlowproteinwasunabletomakedomestican2imalshowthebestperformanceastheintactpro2teindiets

[122]

sideofevertedsacs

[526]

.Theseresultssuggested

thatthecharacteristicsofsmallpeptideabsorp2tionprobablyvariedwithanimalspecies.Todayalltheknowncharacteristicsofsmallpeptideab2sorptionwerealmostestablishedonrelativetis2suesorsmallintestinalpreparationsfromthecommonexperimentalanimalssuchasfrog,mice,rat,guineapig,hamster,rabbit,monkeyandmankind,itisnotveryclearwhethertheknowncharacteristicsareconsistentwiththepeptideab2sorptionfeaturesofdomesticanimals.Itiswell2knownthattransportofaminoacidsinsmallin2testineofdomesticanimalhasthedistinctivecharacteristicsofdependingonNastillunclearthatwhetherNa

+

+

,suggestingpeptidebeessentialto

nutritionrequirementofdomesticanimal.Trans2portcarriersofsmallpeptiderecognizedtoexistinsmallintestineofdomesticanimal

[3]

proved

thatsmallpeptideabsorptionpathwayinsmallin2testineofdomesticanimaldoesindeedobjectivelyexist,whichprovidedfundamentalbasisforpep2tidenutritiontheoryofdomesticanimal.There2sultofpeptideabsorptionindomesticanimalshowedthatcertainpeptidesproducedbyfeedproteinbeinghydrolyzedinchicksmallintestinecouldenterbloodcirculationinintactform

[4]

,whileitis

.

affectsthetrans2

Thestudiesonbothperfusioninvivoandevertedintestinalsacsshowedthatpigletsmallintestinehadtheabilityofabsorbingdipeptideintheformofpeptide,howeverintactdipeptidecouldbefoundneitherinportalveinbloodnorintheother

Datereceived:2006208226

portofsmallpeptideinsmallintestineofdomes2ticanimals.OnthebasisofourpreviousstudiesthatGly2Prowasunhydrolyzedinpigletsmallin2testinalBBMVeffectofNa

+

[7]

andinordertoelucidatethe

transmembranetransportofGly

2

Foundationproject:thisworkwassupportedbyNationalNaturalScienceFoundation(39870583).

Authorinformation:DAIJian2guo(19732),male,borninDanjiangkoucity,Hubeiprovince,associateprofessor,Ph.D.,mainlyworkon

mono2gastricanimalnutrition,nowworkinginShenhenPolytechnic,E2mail:jgdai@263.net.

3Correspondingauthor,Professor,E2mail:defali@public2.bta.net.cn.

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