微透析技术连续监测大鼠肝移植后吲哚胺2,3-双加氧酶在体活性

目的 观察肝移植后肝内吲哚胺2,3-双加氧酶(IDO)在体活性,探讨肝移植免疫排斥对IDO酶活性的影响.方法 施行假手术、同品系(SD→SD)及异品系(Wistar→SD)大鼠肝移植各10例.术后在肝内植入微透析探针,连续收集透析液,HPLC测定色氨酸及犬尿氨酸浓度,以表明IDO酶在体活性.结果 假手术、同品系及异品系组在术后2周内色氨酸浓度均值分别为97.14、85.71、53.07nmol/L(P＜0.05),犬尿氨酸浓度均值分别为3.46、14.58、46.79 nmol/L(P＜0.05),异品系组术后第2天犬尿氨酸浓度即开始增加(20.03nmol/L),第7天达到峰值(70.75nmol/L),此后保持在40.00nmol/L水平以上.结论 同品系或异品系均能诱导移植后肝内IDO酶活性增加,且异品系大鼠肝移植后IDO酶活性表现早而强烈.

Abstract：

Objective To observe the activity of indoleamine 2, 3-dioxygenase (IDO) enzyme in vivo after rat liver transplantation, and the effects of liver transplantation rejection on IDO enzyme activity.Methods Ten SD rats were subjected to othotopic liver transplantations respectively in allogenic OLT group (SD→SD) and heterogenic OLT group (Wistar→SD). In the other 10 SD rats, the blood supply to the liver was obstructed for 15 min for simulating the anhepatic period in the OLT group ( sham group). An in vivo rat liver microdialysis-HPLC system was established on the day I after OLT. The concentrations of kynurenine and tryptophan in dialysate samples were continuously monitored quantitatively and reproducibly for more than 2 weeks in the same animal. Results The average concentrations of tryptophan in dialysate were 97. 14, 85.71, 53.07 nmol/L respectively in the sham, allogenic OLT and heterogenic OLT groups respectively. The concentrations of kynurenine were 3.46, 14. 58, 46.79 nmoL/L in the sham, allogenic OLT and heterogenic OLT groups respectively. The concentration of kynurenine was increased significantly on the day 7 after surgery in heterogeneic OLT group (70. 75 nmol/L). Conclusion The transplantation surgery can induce the activity of IDO enzyme in vivo and accelerate the metabolism of tryptophan in the liver allografts.

Indoleamine2, 3-dioxygenase enzyme activity detected by in vivo liver microdialysis after rat ortho topic liver transplantation

Objective To observe the activity of indoleamine 2, 3-dioxygenase (IDO) enzyme in vivo after rat liver transplantation, and the effects of liver transplantation rejection on IDO enzyme activity.Methods Ten SD rats were subjected to othotopic liver transplantations respectively in allogenic OLT group (SD→SD) and heterogenic OLT group (Wistar→SD). In the other 10 SD rats, the blood supply to the liver was obstructed for 15 min for simulating the anhepatic period in the OLT group ( sham group). An in vivo rat liver microdialysis-HPLC system was established on the day I after OLT. The concentrations of kynurenine and tryptophan in dialysate samples were continuously monitored quantitatively and reproducibly for more than 2 weeks in the same animal. Results The average concentrations of tryptophan in dialysate were 97. 14, 85.71, 53.07 nmol/L respectively in the sham, allogenic OLT and heterogenic OLT groups respectively. The concentrations of kynurenine were 3.46, 14. 58, 46.79 nmoL/L in the sham, allogenic OLT and heterogenic OLT groups respectively. The concentration of kynurenine was increased significantly on the day 7 after surgery in heterogeneic OLT group (70. 75 nmol/L). Conclusion The transplantation surgery can induce the activity of IDO enzyme in vivo and accelerate the metabolism of tryptophan in the liver allografts.