Changes of serum levels of nitric oxide and nitric oxide synthase in patients during liver transplantation / 中国病理生理杂志

ABSTRACT

AIM: To study the changes of serum levels of nitric oxide (NO) and nitric oxide synthase (NOS) in patients during liver transplantation. METHODS: Samples were obtained from 30 patients in end liver disease at five time points during liver transplantation. NO level and NOS activity were measured by radioimmunoassay and colorimetry, respectively. Arterial and mixed venous blood samples used for blood gas analysis were taken at the same time. Intrapulmonary shunt (Qs/Qt) was calculated according to the standard formula. The hemodynamics parameters including continuous cardic output (CO), HR, MABP, CVP, SVR were measured during liver transplantation. RESULTS: (1) NO_2-/NO_3-level at 10 min before anhepatic period was significantly higher than the baseline level. Compared with NO_2-/NO_3-level at 10 min before anhepatic period, NO_2-/NO_3-level at 30 min after anhepatic period was significantly decreased. NO_2-/NO_3-level at 30 min after neohepatic period was significantly higher than the baseline level and at 30 min after anhepatic period. (2) No significant change of tNOS activity was observed. Compared with the baseline activity of inducible nitric oxide synthase (iNOS), the activity at 10 min before anhepatic period and at 30 min after neohepatic period was significantly increased. The activity at 30 min after neohepatic period was significantly higher than that at 30 min after anhepatic period. (3) MABP decreased significantly when opening the inferior vena cava. CO and CVP decreased in the anhepatic stage and increased in the reperfusion stage. SVR increased during anhepatic stage and decreased significantly during neohepatic period. (4) Qs/Qt decreased significantly during anhepatic stage and increased significantly at 30 min after neohepatic period. CONCLUSIONS: Serum level of NO and NOS activity are significantly changed during liver transplantation. High level of NO may result in low systemic vascular resistance and increasing in intrapulmonary shunt.