caa a22 4500 605513864 CHVBK 20210128100702.0 cr unu---uuuuu 210128e20150101xx s 000 0 eng 10.1007/s00360-014-0863-7 doi (NATIONALLICENCE)springer-10.1007/s00360-014-0863-7 Analysis of glycylsarcosine transport by lobster intestine using gas chromatography [Elektronische Daten] [Maria Peterson, Amy Lane, Gregory Ahearn] Gas chromatography was used to measure transepithelial transport of glycylsarcosine (Gly-Sar) by perfused lobster (Homarus americanus) intestine. Unidirectional and net fluxes of dipeptide across the tissue and luminal factors affecting their magnitude and direction were characterized by perfusing the lumen with the dipeptide and measuring its appearance in saline on the serosal side of the organ. Transmural transport of 10mM Gly-Sar resulted in serosal accumulation of only the dipeptide; no appearance of corresponding monomeric amino acids glycine or sarcosine was observed. Carrier-mediated and diffusional transmural intestinal transport of Gly-Sar was estimated at 1-15mM luminal concentrations and followed a curvilinear equation providing a K m=0.44±0.17mM, a J max=1.27±0.12nmolcm−2min−1, and a diffusional coefficient=0.026±0.008nmolcm−2min−1mM−1. Unidirectional mucosal to serosal and serosal to mucosal fluxes of 10mM Gly-Sar provided a significant (p<0.05) net absorptive flux toward the serosa of 3.54±0.77nmolcm−2min−1, further supporting carrier-mediated dipeptide transport across the gut. Alkaline (pH 8.5) luminal pH more than doubled transmural Gly-Sar transport as compared to acidic (pH 5.5) luminal pH, while luminal amino acid-metal chelates (e.g., Leu-Zn-Leu), and high concentrations of amino acids alone significantly (p<0.001) reduced intestinal Gly-Sar transfer by inhibiting carrier transport of the dipeptide. Proposed mechanisms accounting for intestinal dipeptide transport and luminal factors affecting this process are discussed. Springer-Verlag Berlin Heidelberg, 2014 Homarus americanus nationallicence Gas chromatography nationallicence Intestinal transport nationallicence Dipeptide nationallicence Glycylsarcosine nationallicence l -Leucine nationallicence Calcium nationallicence Zinc nationallicence Bis-complex nationallicence Molecular mimicry nationallicence PEPT1 nationallicence PHT1 nationallicence Peterson Maria Department of Biology, University of North Florida, 32224, Jacksonville, FL, USA aut Lane Amy Department of Chemistry, University of North Florida, 32224, Jacksonville, FL, USA aut Ahearn Gregory Department of Biology, University of North Florida, 32224, Jacksonville, FL, USA aut Journal of Comparative Physiology B Springer Berlin Heidelberg 185/1(2015-01-01), 37-45 0174-1578 185:1<37 2015 185 360 https://doi.org/10.1007/s00360-014-0863-7 text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s00360-014-0863-7 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Peterson Maria Department of Biology, University of North Florida, 32224, Jacksonville, FL, USA aut NATIONALLICENCE 700 1- Lane Amy Department of Chemistry, University of North Florida, 32224, Jacksonville, FL, USA aut NATIONALLICENCE 700 1- Ahearn Gregory Department of Biology, University of North Florida, 32224, Jacksonville, FL, USA aut NATIONALLICENCE 773 0- Journal of Comparative Physiology B Springer Berlin Heidelberg 185/1(2015-01-01), 37-45 0174-1578 185:1<37 2015 185 360