Dejong C H, Deutz N E, Soeters P B
Department of Surgery, University of Limburg, Maastricht, The Netherlands.
Gut. 1993 Aug;34(8):1112-9. doi: 10.1136/gut.34.8.1112.
During liver insufficiency, besides portasystemic shunting, high arterial glutamine concentrations could enhance intestinal glutamine consumption and ammonia generation, thereby aggravating hyperammonaemia. To investigate this hypothesis, portal drained viscera (intestines) fluxes and jejunal tissue concentrations of ammonia and glutamine were measured in portacaval shunted rats with a ligated bile duct, portacaval shunted, and sham operated rats, seven and 14 days after surgery, and in normal unoperated controls. Effects of differences in food intake were minimised by pair feeding portacaval shunted and sham operated with portacaval shunted rats with biliary obstruction. At both time points, arterial ammonia was increased in the groups with liver insufficiency. Also, arterial glutamine concentration was raised in all operated groups compared with normal unoperated controls. At both time points, ammonia production by portal drained viscera was reduced in portacaval shunted rats with biliary obstruction, portacaval shunted, and sham operated rats compared with normal unoperated controls, and no major differences were found between these operated groups. At day 7 in all operated groups glutamine uptake by portal drained viscera was lower than in normal unoperated controls, but no major differences were found at day 14. These experiments show that ammonia generation by portal drained viscera remains unchanged in rats with chronic liver insufficiency despite alterations in arterial glutamine concentrations and intestinal glutamine uptake. The hyperammonaemia seems to be mainly determined by the portasystemic shunting.
在肝功能不全期间，除了门体分流外，动脉血中高浓度的谷氨酰胺可增加肠道对谷氨酰胺的消耗并生成氨，从而加重高氨血症。为了验证这一假说，我们测量了门腔分流并结扎胆管的大鼠、门腔分流大鼠和假手术大鼠术后7天及14天的门静脉引流脏器（肠道）氨和谷氨酰胺的通量以及空肠组织浓度，并与正常未手术的对照组进行比较。通过对门腔分流大鼠和假手术大鼠与伴有胆道梗阻的门腔分流大鼠进行配对喂养，尽量减少食物摄入量差异的影响。在两个时间点，肝功能不全组的动脉血氨均升高。此外，与正常未手术对照组相比，所有手术组的动脉谷氨酰胺浓度均升高。在两个时间点，与正常未手术对照组相比，伴有胆道梗阻的门腔分流大鼠、门腔分流大鼠和假手术大鼠的门静脉引流脏器氨生成均减少，且这些手术组之间未发现明显差异。在术后第7天，所有手术组门静脉引流脏器对谷氨酰胺的摄取均低于正常未手术对照组，但在第14天未发现明显差异。这些实验表明，尽管动脉谷氨酰胺浓度和肠道谷氨酰胺摄取发生了变化，但慢性肝功能不全大鼠门静脉引流脏器的氨生成仍保持不变。高氨血症似乎主要由门体分流决定。
