谷氨酰胺对重症急性胰腺炎大鼠胰腺细胞凋亡的影响

目的:研究谷氨酰胺(Gln)对重症急性胰腺炎(SAP)大鼠胰腺细胞凋亡的影响.方法:将80只大鼠随机分成Gln组(n=36)、SAP组(n=36)和对照组(n=8).术后12、24和36 h处死.用高效液相色谱仪测定血浆和胰腺组织内Gln浓度变化,取大鼠胰腺组织,采用原位末端标记法检测胰腺细胞凋亡指数.结果:SAP时,血浆和胰腺组织内Gln浓度明显下降,经肠道补充Gln能明显提高血浆和胰腺组织内Gln浓度.应用Gln治疗可使SAP大鼠胰腺细胞凋亡指数上升,术后12 h,SAP组为(6.88±0.52)个/100细胞,Gln组为(13.07±0.62)个/100细胞,SAP组相比,其他时点差异也均有显著性意义(P＜0.01).结论:SAP时,应用Gln具有促进胰腺细胞凋亡的作用.     

感染状态下肿瘤坏死因子和谷氨酰胺的变化

目的:探讨感染不同时期内毒素、肿瘤坏死因子(TNF-α)和Gln浓度的变化.方法:将90只大鼠随机分为对照组(正常组)和盲肠结扎穿孔(CLP)的实验组.动物模型制作成功后6、12、24、48和72 h采取血浆、肝、骨骼肌和小肠,并检测血浆内毒素、TNF-α和Gln浓度以及肝、骨骼肌和小肠的Gln浓度.结果:在脓毒症大鼠中,血浆内毒素、TNF-α均于6 h开始升高,12 h显著升高,24 h达高峰,48和72 h显著下降;血浆中Gln 6～12 h升高,24～48 h维持高峰,72 h开始下降;肝内Gln浓度6～12 h升高,24 h显著升高至高峰,48和72 h显著下降,并低于正常水平;小肠、骨骼肌中Gln浓度6～12 h下降不显著,24 h以后显著下降,并低于正常水平.结论:在感染早期(6～12 h),血中内毒素和TNF-α浓度显著升高;血浆和肝内Gln浓度显著升高,小肠和骨骼肌中Gln浓度下降不明显.     

原发性高血压大鼠醛固酮与血管重构关系及依普利酮的治疗作用

目的 观察原发性高血压大鼠(spontaneously hypertensive rats,SHR)血管重构与醛固酮的关系以及依普利酮的治疗作用.方法 22只16周龄雄性SHR随机分为依普利酮治疗组[SHR-Epl组,n=11,100mg/(Kg·d)灌胃]和未治疗组(SHR组,n=11),WistarKyoto大鼠为正常对照组(n=12),SHR组和对照组同体积蒸馏水灌胃,共10周.采用放射免疫法检测血浆醛固酮和经反相高效液相提纯肠系膜动脉离体灌注液中血管组织醛固酮;取胸降主动脉和肠系膜上动脉制成石蜡切片,行Masson染色和HE染色,测量两动脉中膜厚度(MT)、中膜横截面积(MCSA)、中膜细胞平均核面积(MNA),分析血管重构指标与醛固酮水平的相关性.结果 SHR-Epl组和SHR组血浆及血管组织醛固酮均高于对照组(P＜0.05),且SHR-Epl组血浆醛同酮高于SHR组(P＜0.01),而血管组织醛固酮低于SHR组(P＜0.01).SHR-Epl组和SHR组胸降主动脉和肠系膜上动脉MT、MCSA和MNA均高于对照组(P＜0.01),并且SHR-Epl组低于SHR组(P＜0.01).胸降主动脉及肠系膜上动脉MT、MCSA、MNA与血浆醛固酮无相关,但与血管组织醛固酮呈正相关(r＞0,P＜0.01).结论 26周龄SHR大鼠血浆和血管组织醛固酮均升高,血管组织醛固酮水平的升高可能是加重血管重构的原因之一.依普利酮治疗可以降低血管组织醛固酮水平,改善血管重构.     

肿瘤坏死因子对谷氨酰胺促大鼠组织蛋白质合成的影响

目的:研究肿瘤坏死因子(TNF-α)对谷氨酰胺(Gin)促大鼠组织蛋白质合成的影响.方法:将30只SD大鼠随机分为TPN(对照)组、Gln组和TNF-α组.所有大鼠均行3d的TPN.对照组仅给予普通TPN液;Gln组在PN液中添加丙氨酰谷氨酰胺二肽,Gln剂量为0.3g/(kg·d),共72h;TNF-α组与Gln组相同,并在第3天持续24h静脉滴注5ug/(kg·d)的TNF-α.所有大鼠均在取材前30min,一次性静脉注射1.0mmol/kg的L-15N亮氨酸.实验结束时,分别测定血浆TNF-α、Gln浓度及骨骼肌、小肠、肝组织的Gln浓度和蛋白质合成率.结果:TNF-α组血浆TNF和Gln浓度以及骨骼肌、小肠、肝组织Gln浓度,均显著高于其他两组;Gln组和TNF-α组骨骼肌、小肠、肝组织中蛋白质合成率均高于对照组,Gln组最高.各组间差异均有显著性意义(P＜0.01).结论:Gln能促进组织蛋白质合成,TNF可抑制感染状态下Gln的促蛋白质合成作用.Gln和TNF均能使血浆及组织中Gln浓度升高.     

三七总皂苷与谷氨酰胺对大鼠肠屏障保护作用的比较

目的比较大鼠肠缺血再灌注损伤时,三七总皂苷(PNS)与谷氨酰胺(Gln)的肠屏障保护作用。方法将60只健康SD大鼠随机分为以下4组:(1)PNS组(n=20),给予PNS胃内灌服,每日3次,每次50mg/kg,共3天;(2)Gln组(n=20),给予Gln胃内灌服,每日3次,每次1g/kg,共3天;(3)单纯手术对照组(n=10),除不夹闭肠系膜上动脉(SMA),其余操作同模型对照组;(4)模型对照组(n=10)。均在最后一次给药2小时后进行手术,夹闭SMA造成肠缺血,1小时后恢复SMA血流,再灌注3小时后分别观察血浆内毒素水平,肝、脾和肠系膜淋巴结的细菌移位率及小肠组织病理学改变。结果(1)模型对照组、PNS组和Gln组大鼠肠道细菌移位率分别为73.33%、45.00%和46.67%,明显高于单纯手术对照组的3.33%(P均<0.01);而模型对照组的细菌移位率也明显高于PNS组和Gln组(P均<0.05);PNS组与Gln组之间差异无显著性(P>0.05)。(2)模型对照组、PNS组和Gln组大鼠血浆内毒素水平分别为(0.553±0.039)、(0.318±0.061)和(0.336±0.05)EU/ml,明显高于单纯手术对照组的(0.152±0.052)EU/ml(P均<0.01);而模型对照组的血浆内毒素水平也明显高于PNS组和Gln组(P均<0.05);PNS组与Gln组之间差异无显著性(P>0.05)。(3)电镜下可见模型对照组损伤较严重,PNS组与Gln组损伤较轻。光镜下chiu分级,PNS组与Gln组相比差异无显著性(P>0.05),但PNS组及Gln组与模型对照组相比损伤均明显减轻(P均<0.01)。结论PNS和Gln胃内灌服给药对缺血再灌注3小时的大鼠肠黏膜屏障具有一定保护作用,二者差异无显著性。     

肿瘤坏死因子对谷氨酰胺调控大鼠肝蛋白质合成的影响

目的:研究肿瘤坏死因子(TNF-α)对谷氨酰胺(Gln)调控大鼠肝蛋白质合成的影响.方法:将30只雄性SD大鼠,随机分为A(TPN)组;B(TPN Gln)组;C(TPN Gln TNF-α)组,均行72 h全肠外营养.B组加用丙氨酰谷氨酰胺二肽,其中Gln剂量为0.3 g/(kg·d),计72 h.C组在B组的基础上于实验结束前24 h持续静脉滴注TNF-α,速度为5 μg/(kg·h).所有大鼠均在实验结束前0.5 h,一次性静脉注射L-15N 亮氨酸1.0 mmol/kg.实验结束时,分别测定血浆中TNF-α浓度,血浆及组织中Gln浓度,并测定肝组织的蛋白质合成率.结果:B组血浆及肝组织中Gln浓度高于A组,但两组均低于C组;B组肝蛋白质合成率高于A组,C组低于B组.结论:TNF-α能升高血浆及肝组织中Gln的浓度;Gln能促进肝蛋白质合成;而Gln这种促肝蛋白质合成作用可被TNF-α抑制.     

肝纤维化患者超声下门静脉和脾静脉血流动力学变化的研究

目的 探讨慢性肝炎患者门静脉和脾静脉血流动力学改变与肝纤维化程度间关系.方法 应用彩色多普勒超声检测了120例慢性肝炎患者的门、脾静脉血流变化.全部病例均行超声引导下肝组织活检病理检查,将超声结果与肝纤维化病理分期进行对照分析.结果 将患者按纤维化程度分为轻度(S0～S1)、中度(S2～S3)和重度(S4).重度纤维化较轻中度门静脉内径(Dpv)、脾静脉内径(Dsv)明显增宽(P<0.05);门静脉血流速度(Vpv)明显降低(P<0.01),而脾静脉血流速度(Vsv)明显加快(P<0.05);脾静脉血流量(Qsv)明显增大(P<0.01).结论 彩色多普勒超声检测门静脉、脾静脉血流动力学对肝纤维化程度的判断具有很好的参考价值.     

谷氨酰胺双肽对放射性肠炎大鼠结局的影响

目的:评价丙氨酰-谷氨酰胺双肽(Ala-Gln) TPN对放射性肠炎大鼠结局的影响.方法:将70只大鼠随机分为四组,即对照组(n=10);实验组腹部接受单剂9.5 Gy60Co照射(AR),分为腹部辐射组(n=20);腹部辐射+TPN组(n=20);腹部辐射+TPN+Ala-Gln组(n=20).分别观察大鼠死亡率、体质量、小肠绒毛高度和面积,肝、脾、门静脉血、肠系膜淋巴结,腹腔渗出液作细菌培养,检测血清肿瘤坏死因子-α(TNF-α)和可溶性白细胞介素2受体(sIL-2R).结果:腹部辐射+TPN+Ala-Gln组大鼠7 d和14 d时死亡率和体质量丢失均最低;绒毛高度和面积仅轻度下降;肝、脾、门静脉血、肠系膜淋巴结和腹腔渗出液中细菌培养阳性率亦最低;血清TNF-α、sIL-2R恢复最快.结论:TPN液中添加Ala-Gln治疗放射性肠炎大鼠,可显著减少体质量丢失,减少肠道细菌移位,增加小肠绒毛高度和面积,改善机体免疫功能,降低病死率,从而显著改善放射性肠炎大鼠的预后.     

谷氨酰胺对急性重症胰腺炎大鼠胰腺继发感染的影响

目的 探讨谷氨酰胺能否减少急性重症胰腺炎（SAP）大鼠胰腺继发感染的发生，方法 SD大鼠48只，随机分成6组（n=8)。A组：假手术 肠外营养支持（PN）1d;B组：SAP PN1d；C组：SAP 谷氨酰胺（Gln)1d；D组：假手术 PN7d；E组；SAP PN7d；F组：SAP Gln7d。观察各组细菌移位情况及胰腺继发感染情况。结果 各脏器培养出的细菌多为肠道常驻菌，F组大鼠肠系膜淋巴结（MLN）及胰腺的细菌培养阳性率明显低于E组。结论 谷氨酰胺能减少急性重症胰腺炎大鼠肠道细菌移位。从而减少胰腺继发感染的发生。     

肠内营养对重症急性胰腺炎大鼠糖皮质激素受体和热休克蛋白70表达的影响

目的:观察肠内营养(EN)对重症急性胰腺炎(SAP)大鼠糖皮质激素受体(GR)和热休克蛋白70(Hsp70)的变化及其影响.方法:采用逆行肝胰管注射牛磺胆酸钠造成SAP模型.将60只大鼠随机分成肠外营养(PN)组,(n=25)、EN组(n=25)和对照组(n=10).PN和EN分别采用经右颈外静脉置管输液和经胃造口空肠上段给营养液的方法.各组建模成功后,均应用奥曲肽皮下注射作基础治疗.于第5天各组分别处死5只大鼠、第10天分别处死全部存活大鼠,观察胰腺、肝、肾、肺和小肠的病理改变,并采用蛋白印迹法测定各组织的GR和Hsp70含量,观察每组第5天和10天的累积病死率.结果:①PN组和EN组大鼠各时段各组织的GR水平明显低于对照组(P＜0.01)、Hsp70明显高于对照组(P＜0.01～0.05);②除肾外,EN组大鼠各时段各组织的GR和Hsp70含量明显高于PN组(P＜0.01～0.05);③对照组大鼠各时段胰腺、肝、肾、肺和小肠的病理检查基本正常,PN组和EN 组各时段上述组织存在明显的病理改变,EN组的病理改变较PN组明显减轻;④EN组大鼠第10天的生存率略高于PN组.结论:在重症急性胰腺炎大鼠模型中,可见GR水平降低和Hsp70水平升高,EN能改善SAP大鼠的组织损害,提高其生存率.     

肠内营养中应用谷氨酰胺对重症急性胰腺炎大鼠继发感染的影响

目的探讨早期肠内营养中应用谷氨酰胺（Gln）对重症急性胰腺炎（SAP）大鼠继发感染的影响。方法雄性SD大鼠95只，随机分成模型1天组、对照组、SAP＋肠外营养（PN）组、SAP＋肠内营养（EN）组、SAP＋EN＋Gln组，除模型1天组外，各组又分为4天喂养组和7天喂养组。分别在第4、7天检测各组各项指标，主要包括细菌移位、血浆内毒素、二胺氧化酶、肠转运功能。结果肠系膜淋巴结和肝培养出的细菌多为革兰氏阴性杆菌，以大肠杆菌为主，SAP＋EN、SAP＋EN＋Gln组显著低于SAP＋PN组（P〈0．01），SAP＋EN＋Gln组低于SAP＋EN组（P〈0．05）。各SAP组血浆内毒素水平显著高于对照组，以SAP＋PN组最高，SAP＋EN、SAP＋EN＋Gln组显著低于SAP＋PN组（P〈0．01），SAP＋EN组高于SAP＋EN＋Gln组（P〈0．05）。SAP＋PN7天组明显高于4天组（P〈0．05）。各SAP组发病4天后血浆DAO活性明显下降（P〈0．01）；7天后SAP＋EN＋Gln组回升和对照组无差异，其余各SAP组继续下降，以SAP＋PN组为甚（P〈0．01）。各SAP组的肠转运系数显著降低（P〈0．05，P〈0．01）；SAP＋EN、SAP＋EN＋Gln组显著高于SAP＋PN组（P〈0.05，P〈0．01）；SAP＋EN＋Gln和SAP＋EN组之间差异无显著性。结论肠内营养中应用谷氨酰胺能更有效地降低SAP大鼠肠道细菌移位，从而减少胰腺继发感染的发生。     

谷氨酰胺和精氨酸联合应用对化疗后大鼠肠屏障的保护作用

目的 观察谷氨酰胺(Gln)和精氨酸(Arg)联合应用对腹腔注射氟尿嘧啶(5-FU)化疗后大鼠肠屏障的保护作用.方法 将40只接受5-FU化疗的健康雄性SD大鼠随机分为单纯肠内营养组、Gln组(肠内营养+Gln)、Arg组(肠内营养+Arg)和Arg+Gln组(肠内营养+Arg+Gln)4组,每组10只.在化疗前后测定各组大鼠体重、尿乳果糖/甘露醇比值(L/M),并在第8天测定门静脉血内毒素,进行门静脉血和淋巴结培养并测定回肠绒毛高度和回、结肠肠壁厚度.结果 除单纯肠内营养组外,其余各组大鼠体重均明显增加(P<0.05);Arg+Gln组体重增加幅度明显低于Gln组(P=0.002),与Arg组差异无统计学意义(P>0.05).化疗后各组L/M值均明显增加(P<0.05);单纯肠内营养组的增加幅度明显高于其他各组(P=0.000),其余各组间差异无统计学意义(P>0.05).单纯肠内营养组的血内毒素水平明显高于其他各组(P=0.000);Gln组明显低于Arg组(P=0.035);Arg+Gln组明显高于Gln组(P=0.000),但与Arg组差异无统计学意义(P=0.109).单纯肠内营养组的回肠绒毛高度和回肠壁厚度明显低于其他各组(P=0.000),结肠壁厚度明显低于Arg组和Arg+Gln组(P=0.000),与Gln组差异无统计学意义(P=0.058);Gln组的回肠壁厚度(P=0.040)和结肠壁厚度(P=0.010)明显高于Arg组,回肠绒毛高度与Arg组差异无统计学意义(P=0.286);Gln组回肠壁厚度明显高于Arg+Gln组(P=0.028),结肠壁厚度(P=0.462)和回肠绒毛高度(P=0.190)与Arg+Gln组差异无统计学意义;Arg组结肠壁厚度明显低于Arg+Gln组(P=0.010),回肠绒毛高度(P=0.803)及回肠壁厚度(P=0.059)与Ag+Gln组差异无统计学意义.各组间门静脉血和淋巴结细菌培养结果差异无统计学意义(P>0.05).结论 Arg、Gln对腹腔注射5-FU化疗后大鼠肠屏障功能具有保 护作用,Gln的保护作用略优于Arg,两者没有明显的协同作用.     

谷氨酰胺和精氨酸联合应用对化疗后大鼠肠屏障的保护作用

目的 观察谷氨酰胺(Gln)和精氨酸(Arg)联合应用对腹腔注射氟尿嘧啶(5-FU)化疗后大鼠肠屏障的保护作用.方法 将40只接受5-FU化疗的健康雄性SD大鼠随机分为单纯肠内营养组、Gln组(肠内营养+Gln)、Arg组(肠内营养+Arg)和Arg+Gln组(肠内营养+Arg+Gln)4组,每组10只.在化疗前后测定各组大鼠体重、尿乳果糖/甘露醇比值(L/M),并在第8天测定门静脉血内毒素,进行门静脉血和淋巴结培养并测定回肠绒毛高度和回、结肠肠壁厚度.结果 除单纯肠内营养组外,其余各组大鼠体重均明显增加(P<0.05);Arg+Gln组体重增加幅度明显低于Gln组(P=0.002),与Arg组差异无统计学意义(P>0.05).化疗后各组L/M值均明显增加(P<0.05);单纯肠内营养组的增加幅度明显高于其他各组(P=0.000),其余各组间差异无统计学意义(P>0.05).单纯肠内营养组的血内毒素水平明显高于其他各组(P=0.000);Gln组明显低于Arg组(P=0.035);Arg+Gln组明显高于Gln组(P=0.000),但与Arg组差异无统计学意义(P=0.109).单纯肠内营养组的回肠绒毛高度和回肠壁厚度明显低于其他各组(P=0.000),结肠壁厚度明显低于Arg组和Arg+Gln组(P=0.000),与Gln组差异无统计学意义(P=0.058);Gln组的回肠壁厚度(P=0.040)和结肠壁厚度(P=0.010)明显高于Arg组,回肠绒毛高度与Arg组差异无统计学意义(P=0.286);Gln组回肠壁厚度明显高于Arg+Gln组(P=0.028),结肠壁厚度(P=0.462)和回肠绒毛高度(P=0.190)与Arg+Gln组差异无统计学意义;Arg组结肠壁厚度明显低于Arg+Gln组(P=0.010),回肠绒毛高度(P=0.803)及回肠壁厚度(P=0.059)与Ag+Gln组差异无统计学意义.各组间门静脉血和淋巴结细菌培养结果差异无统计学意义(P>0.05).结论 Arg、Gln对腹腔注射5-FU化疗后大鼠肠屏障功能具有保 护作用,Gln的保护作用略优于Arg,两者没有明显的协同作用.     

Alanyl-glutamine-supplemented parenteral nutrition prevents intestinal ischemia-reperfusion injury in rats

BACKGROUND: Intestinal ischemia-reperfusion (I/R) injury plays an important role in the pathogenesis of systemic inflammation and multiple-organ failure. We studied whether glutamine, the primary fuel of the small intestine, prevents intestinal mucosal damage after intestinal I/R in rats. METHODS: Rats were randomly divided into 4 groups: a sham-standard amino acid (SAA) group (n = 8); a sham-glutamine (Gln) group (n = 8); an I/R-SAA group (n = 10); and an I/R-Gln group (n = 9). Alanyl-glutamine solution was produced by replacing 36% of the total amino acid nitrogen with Gln. The superior mesenteric artery was ligated. After 60 minutes of ischemia, reperfusion was initiated and infusion was started. After 24-hour reperfusion, the intestinal segment was removed for morphological and biochemical analysis, and blood samples were drawn from the portal vein. Fluorescein isothiocyanate-conjugated dextran 70,000 (FITC-dextran) was infused into the duodenum 2 hours before animal death. RESULTS: In the I/R-SAA group, extensive epithelial sloughing and mucosal ulceration of villous tips were observed, whereas these findings did not occur in the I/R-Gln group. Mucosal wet weight, DNA, and protein content decreased significantly in the I/R-SAA group compared with the sham-SAA group and increased significantly in the I/R-Gln group compared with the I/R-SAA group. Plasma FITC-dextran significantly increased in the I/R-SAA group compared with the sham-SAA group, but the plasma level in the I/R-Gln group was comparable with that of each sham group. Mucosal glutaminase activity significantly increased in both the I/R-SAA and I/R-Gln groups compared with the sham-SAA and sham-Gln groups, respectively. CONCLUSIONS: Alanyl-glutamine protects against morphologic and functional mucosal injury after intestinal I/R in rats.     

Net flux of folates and vitamin B12 through the gastrointestinal tract and the liver of lactating dairy cows.

In study 1, four cows had a ruminal canula, a catheter in the right ruminal vein and an ultrasonic flow probe around the right ruminal artery; a catheter was placed in the auricular artery on experimental days. Blood samples were taken every 10 min from -20 to 60 min after ruminal infusion of 5.79 mmol pteroylmonoglutamic acid and cyanocobalamin. There was a net release of these vitamins across the rumen wall following the infusion (P=0.06). In studies 2 and 3, four cows had catheters in the portal, one hepatic and two mesenteric veins and one mesenteric artery. Plasma flow was determined using p-aminohippurate. In study 2, blood samples were taken before and every 30 min for 6 h after feeding 0 or 4 mg of pteroylmonoglutamic acid. Flow of folates through the portal-drained viscera (PDV) and the total splanchnic tissues (TSP) tended to increase with the ingestion of pteroylmonoglutamic acid (P=0.19). In study 3, blood samples were collected every 30 min for the first 3 h to calculate plasma flow and basal net fluxes of folates and vitamin B12. The cows were fed 2.6 g pteroylmonoglutamic acid and 500 mg cyanocobalamin; blood samples were taken every 2 h for 24 h. Vitamin supplements increased the net release of folates and vitamin B12 from PDV (P=0.04) and TSP (P=0.13). The present results demonstrate that, in dairy cows, at doses reported to improve animal performance, passage of pteroylmonoglutamic acid to the portal blood appears during the 6 h following its ingestion, whereas for cyanocobalamin, it is a slow process, not yet completed 24 h after its ingestion.     

Splanchnic amino acid balance is affected by moderate variations of dietary protein in the developing Zucker rat

This study attempted to determine the influence of moderate chronic variations in dietary protein intake, on splanchnic amino acid balances. Two series of 30-day-old male lean (Fa/?) Zucker rats were fed ad libitum for 30 days with either a standard diet (reference diet: RD), a high-protein diet (HP) (35%) or a low-protein diet (LP) (9%). After 30 days of dietary treatment, blood was withdrawn from hepatic vein, portal vein and arterial aorta in one set of rats. In another series the splanchnic organ blood flows were determined using fluorescent microspheres. From the individual amino acid concentration in each sample and the blood flows, we calculated the intestinal and hepatic balances. There were no significant differences in the hepatic arterial, portal or supra-hepatic flows induced by dietary protein content. The RD group showed a marked intestinal uptake of Gln and Cit and a net release of Pro, Ala and Gly. The LP group showed the same pattern, with increased release of Ala and Gly. In contrast to this limited amino acid release, the HP group showed a generalized net release of amino acids from the intestine. The RD group only show a net Gln release from the liver. Conversely, the HP group showed net uptake of Gln, Pro, Ala, Tyr and Lys, and the LP group took up Gly and Ala and released Asn, Gln and Cit. Our results indicate that growing Zucker rats respond to long-term moderate changes in the protein intake, diminishing the growth pattern only in the LP group, but not in the HP group. In spite of the limited amino acid supply, the LP group followed a similar pattern of intestinal balance for Ala, Gln, Pro, Gly and Cit, as showed by the RD group. On the other hand, excess of dietary amino acids in the HP group seems to promote a lower utilization of Gln by intestine probably due to an increased release of Ala instead of Gln from peripheral tissues.     

Splanchnic amino acid balance is affected by moderate variations of dietary protein in the developing Zucker rat

This study attempted to determine the influence of moderate chronic variations in dietary protein intake, on splanchnic amino acid balances. Two series of 30-day-old male lean (Fa/?) Zucker rats were fed ad libitum for 30 days with either a standard diet (reference diet: RD), a high-protein diet (HP) (35%) or a low-protein diet (LP) (9%). After 30 days of dietary treatment, blood was withdrawn from hepatic vein, portal vein and arterial aorta in one set of rats. In another series the splanchnic organ blood flows were determined using fluorescent microspheres. From the individual amino acid concentration in each sample and the blood flows, we calculated the intestinal and hepatic balances. There were no significant differences in the hepatic arterial, portal or supra-hepatic flows induced by dietary protein content. The RD group showed a marked intestinal uptake of Gln and Cit and a net release of Pro, Ala and Gly. The LP group showed the same pattern, with increased release of Ala and Gly. In contrast to this limited amino acid release, the HP group showed a generalized net release of amino acids from the intestine. The RD group only show a net Gln release from the liver. Conversely, the HP group showed net uptake of Gln, Pro, Ala, Tyr and Lys, and the LP group took up Gly and Ala and released Asn, Gln and Cit. Our results indicate that growing Zucker rats respond to long-term moderate changes in the protein intake, diminishing the growth pattern only in the LP group, but not in the HP group. In spite of the limited amino acid supply, the LP group followed a similar pattern of intestinal balance for Ala, Gln, Pro, Gly and Cit, as showed by the RD group. On the other hand, excess of dietary amino acids in the HP group seems to promote a lower utilization of Gln by intestine probably due to an increased release of Ala instead of Gln from peripheral tissues.     

Effect of level of nutrition on splanchnic blood flow and oxygen consumption in sheep

The objective of the present study was to measure changes in splanchnic blood flow and oxygen consumption in sheep fed on a high-concentrate diet ad lib. (ADLIB) or an amount sufficient to maintain body-weight (MAINT) for 21 d. Eleven ram lambs were surgically implanted with chronic indwelling catheters in the portal, hepatic and mesenteric veins and mesenteric artery to measure blood flow and net O2 flux through the liver and portal-drained viscera (PDV). During the 21 d period, PDV (P less than 0.05) and liver (P less than 0.01) blood flow increased in ADLIB and decreased in MAINT lambs (treatment x day, linear). After 21 d, O2 consumptions in PDV and liver of MAINT lambs were 37 and 63% lower than in ADLIB lambs. In the control period, total splanchnic tissues represented an average of 52% of whole body O2 consumption. After 21 d, the relative contributions of PDV and liver to whole-body O2 consumption were 28 and 41% in ADLIB and 19 and 22% in MAINT lambs respectively. Allometric regression variables indicate that liver O2 consumption responds more rapidly to changes in metabolizable energy intake than portal O2 consumption. These results indicate that blood flow and O2 consumption in both PDV and liver are related to level of nutrition. Furthermore, splanchnic tissues represent a significant component of whole-body O2 consumption that is subject to manipulation by level of nutrition.     

Prevention of bacterial translocation using glutamine: a new strategy of investigation

OBJECTIVE: This study investigated the role of glutamine (Gln) on bacterial translocation in an intestinal obstruction model by using Escherichia coli labeled with technetium 99m (99mTc-E. coli). METHODS: Intestinal obstruction was performed by a single ligature of the terminal ileum in rats. Animals in the control group (group 1) were sham operated (not obstructed). Experimental group 2 had intestinal obstruction. Groups 1 and 2 were not treated with Gln. Groups 3 and 4 were treated with Gln for 7 d before surgery with 250 and 500 mg x kg(-1) x d(-1), respectively. A suspension containing 100 million colony-forming units/mL of (99m)Tc-E. coli was injected into the lumen of the ileum. Twenty-four hours after surgery, blood, mesenteric lymph nodes, livers, spleens, and lungs were collected for determination of radioactivity. The Mann-Whitney U test was performed for statistical analysis. P 相似文献