Effects of continuous sedation with propofol on peripheral blood mononuclear cell and intercellular adhesion molecule in beagles with combined burn-blast injuries

Abstract

To observe the effects of continuous sedation with propofol on peripheral blood mononuclear cell (PBMC) and intercellular adhesion molecule 1 (ICAM-1) in beagles with combined burn-blast injuries. A total of 32 male beagles were randomly divided into 4 groups of normal control (NC), combined injury control (CC), propofol 1 (P1) and propofol 2 (P2) (n = 8 each). Except for NC group, the other 3 groups were subject to severe combined burn-blast injury. And sodium lactate Ringer's solution was infused after trauma according to the Parkland formula, including NC group. At the same time, P1 and P2 groups received continuous intravenous infusions of 2 mg×kg(-1)×h(-1), 5 mg×kg(-1)×h(-1) doses of propofol respectively for 72 hours. The serum concentrations of ICAM-1 and lymphocyte function associated antigen-1 (LFA-1) were measured by enzyme-linked immunosorbent assay (ELISA) at 6, 24, 48, 72 h post-injury. Flow cytometry was used to detect the major histocompatibility complex (MHC) antigen expression on CD14(+) monocytes, CD4(+)/CD8(+) T lymphocyte rate and PBMC apoptosis rate. The level of ICAM-1 in CC group ((10.5 ± 1.1), (10.8 ± 1.3), (12.3 ± 1.4) ng/ml) was significantly higher than that in NC group ((7.4 ± 1.4), (7.4 ± 1.1), (7.4 ± 1.6) ng/ml) at 12, 24, 48 h post-injury (all P < 0.05). The level of ICAM-1 in P1 group was significantly lower than that in CC group ((10.7 ± 1.3) vs (12.3 ± 1.4) ng/ml) while the level of ICAM-1 in P2 group was significantly lower than that in P1 group at 72 h post-injury ((8.8 ± 1.4) vs (10.7 ± 1.3) ng/ml) (both P < 0.05). The level of LFA-1 in CC group ((7.3 ± 1.3), (8.4 ± 1.3), (9.6 ± 1.7) ng/ml) was significantly higher than that in NC group ((5.1 ± 1.2), (5.4 ± 1.3), (5.8 ± 1.2) ng/ml) at 24, 48, 72 h post-injury (all P < 0.05). MHC antigen expression on the CD14(+) monocytes of P2 group was obviously higher than that of CC and P1 groups ((46 ± 13)% vs (26 ± 15)% and (32 ± 12)%, both P < 0.05). The CD4/CD8 rate in P1 and P2 was significantly higher than that in CC group (1.71 ± 0.26, 1.82 ± 0.31 and 1.81 ± 0.24, 1.96 ± 0.24 vs 1.41 ± 0.34, 1.34 ± 0.26) at 48, 72 h post-injury (all P < 0.05). At 72 h post injury, the PBMC apoptosis rate in CC and P1 group was obviously higher than that of the NC group ((2.57 ± 0.21)% and (1.64 ± 0.10)% vs (0.81 ± 0.11)%) (both P < 0.01); the apoptosis rate in P2 group was significantly lower than that in P1 group ((1.09 ± 0.15)% vs (1.64 ± 0.10)%) (P < 0.01). Propofol may improve the immune function after combined burn-blast injuries through suppressing an excessive release of ICAM-1 and PBMC apoptosis in a concentration-dependent manner.