Effects Of Intestinal Trefoil Factor And Glutamine On Intestinal Glutamine Transport After Burn Injury

ObjectiveTo observe the effects of intestinal trefoil factor(ITF) and glutamine (Gln) onintestinal glutamine transport capacity after burn injury and to explore its possiblemechanism.Methods1. One hundred and sixty Sprague-dawley rats were randomly divided into fourgroups, namely normal control (C) group, burned control (B) group, burned+ITF (I)group, and burned+Gln (G) group. The rats in C group were only received anaesthesiaand shaved. The rats from other three groups were inflicted with30%total body surfacearea of full thickness burn by soaking94℃water for18seconds. Burned rats werequickly injected with lactated ringer’s solution via intraperitoneal injection forresuscitation. After burn injury, rats were fed with normal diet and drinking water. Ingroup I, rats were supplied ITF (1mg/kg.d, bid) with intragastric administration after6hburn injury. In group G, rats were supplied Gln (1g/kg.d, bid) with intragastricadministration. In group B, rats were perfused with the same volume of saline.According to different experimental purposes, observation phase include post burn1day(PBD1), PBD3, and PBD5.(1) Intestinal brush border membrane vesicles (BBMV) were prepared bymagnesium precipitation. The transport rate of [3H]-Gln into BBMV was quantitativedetected by using radioactivity count per minute(CPM).(2) Intestinal epithelial cells (IEC) were separated by scraping and rinsingintestinal mucosa. The transport rate of [3H]-Gln into IEC was quantitative detected byusing radioactivity count per minute (CPM).(3) The protein content of glutamine transporter ASCT2and B0AT1on intestinalepithelial cell were measured by using western blot.2. Using rat intestinal epithelial cell (IEC-6) lines to establish hypoxia cell culturemodel in vitro. The culture cells were randomly divided into four groups, namelynormal control (C) group, hypoxia control (H) group, hypoxia+ITF (I) group, and hypoxia+Gln (G) group. The protein content and its phosphorylation level of AMPKand ACC were measured by western blot.Results1. The overall trend of Gln transport in BBMV and IEC was not changesignificantly after burn injury, except remarkable decreased PBD1(P<0.05). Glntransport rate of sodium dependent and sodium independent was slightly increased fromPBD3to PBD5(P>0.05).2. Compared with group B, Gln transport rate in BBMV and IEC was elevatedobviously with supplement Gln (1g/kg.d). The Gln transport rate of sodium dependentin BBMV was increased76%,73%and23%PBD1, PBD3, and PBD5, respectively. TheGln transport rate of sodium independent in BBMV was raised62%,66%and21%,respectively. In IEC, the increased range was43%,44%and31%(sodium dependent),and6%、39%and63%(sodium independent),respectively.3. Compared with group B, Gln transport rate in BBMV and IEC was raisedmarkedly with supplement ITF(1mg/kg.d). The Gln transport rate of sodium dependentin BBMV was increased30%,12%and32%PBD1, PBD3, and PBD5, respectively. TheGln transport rate of sodium independent in BBMV was raised25%,6%and64%,respectively. In IEC, the increased range was14%,21%and31%(sodium dependent),and7%,15%and37%(sodium independent), respectively.4.The change of ASCT2protein in BBMV was not obviously, and B0AT1wassignificantly decreased from PBD1to PBD5. Compared with group B, the change ofASCT2was not obviously, and B0AT1was significantly increased1.57,2.37and2.38times with supplement Gln from PBD1to PBD5, respectively. ASCT2was increased1.41,2.33and1.78fold, and B0AT1was raised1.22,1.78and1.15fold after ITFadministration, respectively.5. The protein content of AMPK and ACC in IEC-6under hypoxic conditions werenot changed obviously, and the phosphorylation level of AMPK and ACC weresignificantly increased. Compared with hypoxia contral group, the change of AMPKand ACC content were not obviously, but p-AMPK and p-ACC level were significantlyincreased with supplement ITF. Neither AMPK content nor AMPK phosphorylationlevel were changed markedly under glutamine supplementation.Conclusion1. The overall trend of Gln transport in BBMV and IEC is not change significantly after burn injury. Administration Gln or ITF can obviously promote Gln transport inBBMV and IEC.2.The protein content of ASCT2and B0AT1are elevated remarkably with ITFsupplementation. Only B0AT1but not ASCT2is regulated by administration glutamine.3. ITF can activate AMPK signal pathway, while glutamine have no effect onAMPK.