AIMTo observe effect of acute normovolemic hemodilution(ANH) with HAES-balanced solution as diluting agent on levels of cytokines including IL-1, IL-2, IL-6 and TNF-alpha in rabbit serum so as to provide theoretical basis for clinical application.

METHODSA total of 20 healthy adult rabbits were enrolled in the study and randomly divided into two groups (10 rabbits per group), i.e., control group (Group C) and HAES group (Group H). Under anesthesia of the rabbits, we performed incision of trachea, high-frequency jet ventilation and liberation of femoral artery and femoral veins. Group C was free from hemodilution. Group H was injected with dilution (2-fold of blood letting volume) via femoral veins during blood letting of the femoral artery. 6% HAES-steril plus compound solution of sodium lactate, with crystal/gel ratio of 2:1, blood letting volume = TBV x (Ho-Hf)/Hav. All blood was transfused back 60-120 min after blood letting. Venous blood was collected before blood letting (T0) and 30 min (T1), 60 min (T2), 120 min (T3) and 24 h(T4) after blood letting to detect Hb and Hct and measure level of IL-1, IL-2, IL-6 and TNF-alpha in serum.

RESULTSIn Group H, levels of IL-1, IL-2, IL-6 and TNF-alpha in serum were increased from T1 after ANH, reached peak at T3 but showed decrease at T4, with significant difference compared with Group C at T1, T2, T3 and T4 (P < 0.01) and significant difference compared with those before ANH (P <0.01). In Group C, there was no significant difference upon IL-1, IL-2, IL-6 and TNF-alpha in serum at different time points.

CONCLUSIONANH with HAES-balanced solution as diluting agent can up-regulate the levels of cytokines IL-1, IL-2, IL-6 and TNF-alpha in rabbit serum. In the meantime, ANH may arouse eustress with low intensity and short action time, which exerts effect of enhancing immune function of the organisms.