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Sugar transport pathways in enterocytes from chicken rectum and coprodeum
840
Abstracts
G 10 SUGAR TRANSPORTPATHWAYSIN ENTERGCYTESFROM ACUTE EFFECTOF ETHANOLGN 'IHEABSORPTIONOF CHICKENRECTUMAND COPRODEUM.J.M. Planas,M. CEPHALEXIN(CFX)AND CEFADROXIL (CFD). J.G. Oliveras, R. Ferrerand M. Moreto,Dept. de Prieto, J.P. Barrio, A.I. Alvarez,Animal Cii+ncies Fisiologigues, Facultatde Farmiicia,PhysiologyLaboratory.Univ. of Leon. Spain. Univ. de Barcelona,Spain. The in vivo intestinalabsorptionratesof The sugar transportpropertiesof the rectum CFX and CFD, each at concentrationsbetween and coprodeum have been studiedin isolated 5-50 mM, were measuredin rats using a recirenterocytes(Ferreret al., Rev esp. Fisiol culatingperfusiontechniqueat 1 ml/min.The 42, 341, 1986).Leghornchickens4-7 wk-old perfusate contained phenol red as a volume were used. After 60 min incubation,cells indicatorand only CPX or CFD in control from the rectum have a cumulativecapacity rats. It also contained 6% ethanolin the for 3-oximethyl-&glucose (0.1mmol/L) which experimentalrats.Absorptionrateswere nordoublesthat of jejunalcells.The initiala- malizedfor the lengthof the perfusedintesmethyl-D-glucoside (1 nnnol/Linflux through tinal segmentand for the metabolic weight. the apical transport pathway (5.2nmol/mg Resultsagree betterwith a mixed michaelianprot.min)is Na -dependent, phloridzin-sensi-first order mechanismratherthan Michaelistive and is inhibitedby 25 mmol/'L D-glucose. Menten kinetics. Ethanol does not signifiThe initialinfluxof 1 mmol/L2-deoxy-Dglu- cantlyalter Vmax in CFX, but it decreasesin case (2-DoG)(lnmol/mgprot.min)is inhibited CFD. The carrieraffinityconstantKm is in, suggestingthe existence creased for both antibiotics,around two 40% by theophylline of a Na -independent transportpathwayat the times for CFX relativeto CFD. basolateralmembrane.The theophylline insensitive 2-Dot influx is similarto the obtainedusing L-glucose.Coprodealenterocytes are unable to accumulatemonosaccharides and lack any specificmediated transport system (Supportedby CAICYTPB85-0324). G9
11 H+ PERMEABILITYOF APICALMEMBRANEVESICLES FROM THE UPPER GASTROINTESTINALTRACT. J.M. Wilkes,H.J. Ballardand B.H. Hirst,Dept. of Physiological Sciences, Univ. of Newcastle upon Tyne, U.K. G
G 12 CHARACTERIZATIGNOFTHE INTESTINALNa/GLUCOSE CGTRANSPGRT IN XENGPUSCGCYTES.E.M. Wright, M. Coady,T. Ikeda,and M.H. Hediger, Dept. of Physiology,Univ. of California,Los Angeles.
Apical membranevesicleswere isolated from The brush borderNa/glucosecotransporter was the rabbitbrush border (dBBMV)and histamine expressedin the plasmamembrane of Xenopus stimulatedoxynticcells (SAV). Proton per- laevis oocytes after injection of rabbit meation was monitored from acridineorange smallintestinemRNA. The cotransporterwas fluorescence quenching,+following imposition Na-dependent and inhibitedby phlorizin.The of a transmembraneH gradient.The process K of *methyl-&glucopyranosidetransport followedfirst order kinetics,with rate con- w% 0.1 mM, and the maximalvelocitywas destants o 4. 520.22 (n=20)and 2.15k0.14(n= pendenton the amountof mRNA injected. mRNA 14) x lo-?s-f for dBBMV and SAV respectivelyfrom the rabbit descendingcolon failedto (temp=20°C).Fluorescenceanisotropy(r) of expressthis glucose carrier in oocyties. diphenylhexatriene indicatedthe fluidity of These results demonstrate that the Xenopus the lipid bilayer (expressed as (r r)-1, r = oocyteefficientlytranslatesthe mRNA coding and that the limitinganisotropy(0.362)).dBBMe/ and &V for the Na/glucosecotransporter gave values of 0.488+0.013(n=7)and 0.66* oocyte is able to insert fully functional (n==4) respectively. Increasesin temperature,carrierproteininto the plasmamembrane.The and treatmentwith a sqriesof alcohols,in- oocytemay providea usefulmodel system for creased(rdr)-1,and H permeation in the the isolationof the gene for this transport case of SAV than dBBMV.Arrheniusplots of protein. the two parametersdemonstrateddiscontinuities at 30°C in the case of dBBMV,but not SAV.
Abstracts
G 10 SUGAR TRANSPORTPATHWAYSIN ENTERGCYTESFROM ACUTE EFFECTOF ETHANOLGN 'IHEABSORPTIONOF CHICKENRECTUMAND COPRODEUM.J.M. Planas,M. CEPHALEXIN(CFX)AND CEFADROXIL (CFD). J.G. Oliveras, R. Ferrerand M. Moreto,Dept. de Prieto, J.P. Barrio, A.I. Alvarez,Animal Cii+ncies Fisiologigues, Facultatde Farmiicia,PhysiologyLaboratory.Univ. of Leon. Spain. Univ. de Barcelona,Spain. The in vivo intestinalabsorptionratesof The sugar transportpropertiesof the rectum CFX and CFD, each at concentrationsbetween and coprodeum have been studiedin isolated 5-50 mM, were measuredin rats using a recirenterocytes(Ferreret al., Rev esp. Fisiol culatingperfusiontechniqueat 1 ml/min.The 42, 341, 1986).Leghornchickens4-7 wk-old perfusate contained phenol red as a volume were used. After 60 min incubation,cells indicatorand only CPX or CFD in control from the rectum have a cumulativecapacity rats. It also contained 6% ethanolin the for 3-oximethyl-&glucose (0.1mmol/L) which experimentalrats.Absorptionrateswere nordoublesthat of jejunalcells.The initiala- malizedfor the lengthof the perfusedintesmethyl-D-glucoside (1 nnnol/Linflux through tinal segmentand for the metabolic weight. the apical transport pathway (5.2nmol/mg Resultsagree betterwith a mixed michaelianprot.min)is Na -dependent, phloridzin-sensi-first order mechanismratherthan Michaelistive and is inhibitedby 25 mmol/'L D-glucose. Menten kinetics. Ethanol does not signifiThe initialinfluxof 1 mmol/L2-deoxy-Dglu- cantlyalter Vmax in CFX, but it decreasesin case (2-DoG)(lnmol/mgprot.min)is inhibited CFD. The carrieraffinityconstantKm is in, suggestingthe existence creased for both antibiotics,around two 40% by theophylline of a Na -independent transportpathwayat the times for CFX relativeto CFD. basolateralmembrane.The theophylline insensitive 2-Dot influx is similarto the obtainedusing L-glucose.Coprodealenterocytes are unable to accumulatemonosaccharides and lack any specificmediated transport system (Supportedby CAICYTPB85-0324). G9
11 H+ PERMEABILITYOF APICALMEMBRANEVESICLES FROM THE UPPER GASTROINTESTINALTRACT. J.M. Wilkes,H.J. Ballardand B.H. Hirst,Dept. of Physiological Sciences, Univ. of Newcastle upon Tyne, U.K. G
G 12 CHARACTERIZATIGNOFTHE INTESTINALNa/GLUCOSE CGTRANSPGRT IN XENGPUSCGCYTES.E.M. Wright, M. Coady,T. Ikeda,and M.H. Hediger, Dept. of Physiology,Univ. of California,Los Angeles.
Apical membranevesicleswere isolated from The brush borderNa/glucosecotransporter was the rabbitbrush border (dBBMV)and histamine expressedin the plasmamembrane of Xenopus stimulatedoxynticcells (SAV). Proton per- laevis oocytes after injection of rabbit meation was monitored from acridineorange smallintestinemRNA. The cotransporterwas fluorescence quenching,+following imposition Na-dependent and inhibitedby phlorizin.The of a transmembraneH gradient.The process K of *methyl-&glucopyranosidetransport followedfirst order kinetics,with rate con- w% 0.1 mM, and the maximalvelocitywas destants o 4. 520.22 (n=20)and 2.15k0.14(n= pendenton the amountof mRNA injected. mRNA 14) x lo-?s-f for dBBMV and SAV respectivelyfrom the rabbit descendingcolon failedto (temp=20°C).Fluorescenceanisotropy(r) of expressthis glucose carrier in oocyties. diphenylhexatriene indicatedthe fluidity of These results demonstrate that the Xenopus the lipid bilayer (expressed as (r r)-1, r = oocyteefficientlytranslatesthe mRNA coding and that the limitinganisotropy(0.362)).dBBMe/ and &V for the Na/glucosecotransporter gave values of 0.488+0.013(n=7)and 0.66* oocyte is able to insert fully functional (n==4) respectively. Increasesin temperature,carrierproteininto the plasmamembrane.The and treatmentwith a sqriesof alcohols,in- oocytemay providea usefulmodel system for creased(rdr)-1,and H permeation in the the isolationof the gene for this transport case of SAV than dBBMV.Arrheniusplots of protein. the two parametersdemonstrateddiscontinuities at 30°C in the case of dBBMV,but not SAV.