Bremholm Lasse, Hornum Mads, Henriksen Birthe Merete, Larsen Steen, Holst Jens Juul
Department of Gastroenterology, Glostrup Hospital, University of Copenhagen, Denmark.
Scand J Gastroenterol. 2009;44(3):314-9. doi: 10.1080/00365520802538195.
Mesenteric blood flow is believed to be influenced by digestion and absorption of ingested macronutrients. We hypothesized that the intestinotrophic hormone, GLP-2 (glucagons-like peptide 2), may be involved in the regulation of mesenteric blood flow. Changes in mesenteric blood flow were measured by Doppler ultrasound scanning of the superior mesenteric artery (SMA). The aim of the study was to demonstrate the influence of GLP-2 on this flow, expressed as changes in resistance index (RI).
A homogeneous group of 10 fasting healthy volunteers completed a 2-day trial. On day 1, a standard meal was given, and RI measured in the SMA. On day 2, GLP-2 was infused intravenously (IV) at rates of 0.5, 1.0 and 2.0 pmol/kg/min over 3 x 45 min separated by a 15-20 min rest period. After a further 15-20 min of rest, 450 nmol synthetic GLP-2 was given subcutaneously (SC). RI in the SMA was measured before, during and after the meal and GLP-2 infusions.
After IV infusion of GLP-2, the following decreases in RI were observed: 0.5 pmol/kg/min: 2.7% (range 0-6.3%), 1.0 pmol/kg/min: 6.7% (range 0.4-15.9%), 2.0 pmol/kg/min: 15.3% (range 9.6-22.7%) p<0.00802. When given SC, GLP-2 elicited a maximum average change in RI of 15.6% (range 5.0-28.1%). The standard meal elicited a 14.7% (range 8.8-21.6%) change, p<0.020 There was a similar change in RI over time (0-90 min) after a standard meal and after subcutaneous GLP-2, p<0.005.
Our study showed a significant association between IV and SC administration of synthetic GLP-2 and changes in mesenteric blood flow. An exponential dose-response relationship was observed after IV infusion. The meal-induced changes in mesenteric blood flow over time were similar to those obtained by SC GLP-2. Thus, our results support the hypothesis that GLP-2 is an important regulator of mesenteric blood flow.
肠系膜血流被认为受摄入的大量营养素消化和吸收的影响。我们推测肠营养激素胰高血糖素样肽-2（GLP-2）可能参与肠系膜血流的调节。通过对肠系膜上动脉（SMA）进行多普勒超声扫描来测量肠系膜血流的变化。本研究的目的是证明GLP-2对这种血流的影响，以阻力指数（RI）的变化来表示。
一组10名空腹健康志愿者完成了一项为期2天的试验。在第1天，给予标准餐，并测量SMA的RI。在第2天，以0.5、1.0和2.0 pmol/kg/分钟的速率静脉内（IV）输注GLP-2，每次输注45分钟，共输注3次，每次输注之间有15 - 20分钟的休息期。在再休息15 - 20分钟后，皮下注射（SC）450 nmol合成GLP-2。在进餐和GLP-2输注之前、期间和之后测量SMA的RI。
静脉输注GLP-2后，观察到RI有以下降低：0.5 pmol/kg/分钟：2.7%（范围0 - 6.3%），1.0 pmol/kg/分钟：6.7%（范围0.4 - 15.9%），2.0 pmol/kg/分钟：15.3%（范围9.6 - 22.7%），p<0.00802。皮下注射GLP-2时，RI的最大平均变化为15.6%（范围5.0 - 28.1%）。标准餐引起的变化为14.7%（范围8.8 - 21.6%），p<0.020。标准餐和皮下注射GLP-2后，随时间（0 - 90分钟）RI有相似变化，p<0.005。
我们的研究表明，合成GLP-2静脉内和皮下给药与肠系膜血流变化之间存在显著关联。静脉输注后观察到指数剂量反应关系。进餐引起的肠系膜血流随时间的变化与皮下注射GLP-2所获得的变化相似。因此，我们的结果支持GLP-2是肠系膜血流重要调节因子的假设。
