OBJECTIVETo investigate the influence of arginine hydrochloride and arginine acetate on the immune function and acid-base balance in rabbits with severe burns.

METHODSOne hundred and ten flap-eared rabbits were used in the study, in which 8 served as normal control, while the rest were inflicted with 30% TBSA full thickness burn. All the rabbits were divided into 10 groups, i.e. normal control (C, n = 14), burn control (B, n = 14, with intravenous infusion of Ringer's solution), 0.3 g/kg arginine hydrochloride (AH, n = 12), 0.3 g/kg arginine acetate (AA, n = 10), 0.6 g/kg AH (n = 10), and 0.6g/kg AA (n = 10) groups, 1.2 g/kg AH (n = 10), 1.2 g/kg AA (n = 10), 2.4 g/kg AA (n = 14) and 2.4 g/kg AH (n = 12) groups. AA and AH in different doses were fed to rabbits in corresponding groups 2 times a day for 7 days. The changes in the immune function, acid-base balance, chloride ion metabolism, and mortality were determined.

RESULTSDisorder in immune system was found after severe burns, with enhanced immune function at the beginning and weakening afterwards. The lymphocytic transformation rate, the CD4/CD8 ratio, the phagocytosis rate and the chemotactic index of white blood cells on 7 post burn day (PBD) were obviously lower in B group compared with C group (P < 0.05 or 0.01). These indices were obviously higher in 1.2, 2.4 g/kg AA and AH groups than those in B group on 7 PBD (P < 0.05 or 0.01). There was no difference in improvement of immune functions between 0.3, 0.6g/kg AH, AA group and B group. The values of blood pH, base excess (BE), buffer base (BB), HCO(3)(-) level in AH group were significantly lower than those in C group on 7 PBD (P < 0.05 or 0.01), while there were no obvious changes in AA group, they were obviously higher than those in AH group (P < 0.05 or 0.01). The contents of chloride ion in but 2.4 g/kg AH group during 5 to 7 PBD were obviously higher than those in C group and 2.4 g/kg AA group (P < 0.05 or 0.01), while no difference was found between 2.4 g/kg AA and C groups. The mortality in B group was obviously higher than that in 0.3, 0.6, 1.2 g/kg AH and AA groups (P < 0.05 or 0.01), but significantly lower than that in 2.4 g/kg AA and AH groups (P < 0.05).

CONCLUSIONDisorders in immune functions were observed in severely burned rabbits. Administration of arginine acetate as well as arginine hydrochloride could enhance the immune function, but arginine acetate seemed to be safer than arginine hydrochloride. Excessive dosage should be avoided to prevent a rise of the mortality.