Ray Edward C, Avissar Nelly E, Vukcevic Dubravka, Toia Liana, Ryan Charlotte K, Berlanga-Acosta Jorge, Sax Harry C
Department of Surgery, University of Rochester Medical Center, Rochester, New York 14642, USA.
J Surg Res. 2003 Aug;113(2):257-63. doi: 10.1016/s0022-4804(03)00185-9.
Sodium-dependent brush border nutrient transport is decreased 2 weeks after massive enterectomy. This downregulation is ameliorated by a 1-week infusion of parenteral growth hormone (GH) and epidermal growth factor (EGF) started 1 week after resection. We hypothesized that glutamine (GLN) transport would be enhanced by earlier and longer growth factor infusion, with differential effects on the Na(+)-dependent GLN transport systems A, B(0,+), and B0/ASCT2.
New Zealand White rabbits underwent 70% small bowel resection then immediately received parenteral EGF, GH, both, or neither for 2 weeks. Na(+)-dependent 3H-GLN uptake by jejunal and ileal brush-border membrane vesicles was measured and the contribution of systems A, B(0,+), and B0 then determined by competitive inhibition. Data were analyzed using one-way analysis of variance.
In nonresected animals, the relative contribution of the systems was similar in jejunum (A, 9%, B(0,+), 20%; and B0, 71%) and ileum (A, 13%; B(0,+), 27%; and B0, 60%). Na(+)-dependent GLN uptake was reduced by half in resected, untreated controls, primarily because of decreased B(0) activity. EGF or GH alone did not affect Na(+)-dependent GLN transport, but as a combination, increased uptake in the residual ileum and jejunum by 144% and 150%, respectively, over resected controls (P<0.05). This was twice that achieved by delayed and shorter-duration combination treatment. This augmentation was due to a 6.1- to 8.2-fold increase in system A as well as a 3.8- to 3.9-fold enhancement of system B(0,+) activity in remnant ileum and jejunum (P<0.01).
Parenteral EGF and GH, given in combination for 2 weeks immediately after massive enterectomy, synergistically enhance GLN uptake by systems A and B(0,+).
大面积肠切除术后2周，钠依赖性刷状缘营养物质转运减少。在切除术后1周开始进行为期1周的肠外生长激素（GH）和表皮生长因子（EGF）输注可改善这种下调情况。我们推测，更早且更长时间的生长因子输注会增强谷氨酰胺（GLN）转运，对钠依赖性GLN转运系统A、B(0,+)和B0/ASCT2有不同影响。
新西兰白兔接受70%小肠切除术，然后立即接受肠外EGF、GH、两者联合或不接受任何治疗，持续2周。测量空肠和回肠刷状缘膜囊泡对钠依赖性3H-GLN的摄取，并通过竞争性抑制确定系统A、B(0,+)和B0的贡献。数据采用单因素方差分析进行分析。
在未切除小肠的动物中，空肠（系统A占9%，B(0,+)占20%，B0占71%）和回肠（系统A占13%，B(0,+)占27%，B0占60%）中各系统的相对贡献相似。在切除小肠且未接受治疗的对照组中，钠依赖性GLN摄取减少了一半，主要是因为B(0)活性降低。单独使用EGF或GH对钠依赖性GLN转运没有影响，但联合使用时，残余回肠和空肠的摄取量分别比切除术后的对照组增加了144%和150%（P<0.05）。这是延迟和较短疗程联合治疗所达到效果的两倍。这种增强是由于残余回肠和空肠中系统A增加了6.1至8.2倍以及系统B(0,+)活性增强了3.8至3.9倍（P<0.01）。
大面积肠切除术后立即联合给予肠外EGF和GH 2周，可协同增强系统A和B(0,+)对GLN的摄取。
