Effects of Hypertonic Saline and Hydroxyethyl Starch on Myeloid-Derived Suppressor Cells in Hemorrhagic Shock Mice under Secondary Bacterial Attack.

Objectives: The primary target is to reveal whether the resuscitation with hypertonic saline (HTS) or hydroxyethyl starch (HES) would have different effects on the myeloid-derived suppressor cell (MDSC) count and monocytic MDSC (M-MDSC)/granulocytic/neutrophilic MDSC (G-MDSC) rate in the peripheral blood, spleen, and bone marrow nucleated cells (BMNC) in a controlled hemorrhagic shock mouse model under secondary bacterial infection attack, comparing to resuscitation with normal saline (NS) in 72 hours.

Method: After hemorrhagic shock with bacteremia, which is induced by bacterial infection attack, comparing to resuscitation with normal saline (NS) in 72 hours. . After hemorrhagic shock with bacteremia, which is induced by 35218 injection, the mice were distributed into control, NS, HTS, and HES groups. The peripheral blood nucleated cells (PBNC), spleen single-cell suspension, and bone marrow nucleated cells were collected. The flow cytometry was used to detect the MDSC, M-MDSC, and G-MDSC.

Result: In PBNC, after resuscitation with NS, the MDSC was continuously higher, while the rate of M-MDSC/G-MDSC were continuously lower ( < 0.05). In HTS, the MDSC varied, higher at 24 and 72 hours ( < 0.05). In HTS, the MDSC varied, higher at 24 and 72 hours ( < 0.05). In HTS, the MDSC varied, higher at 24 and 72 hours ( < 0.05). In HTS, the MDSC varied, higher at 24 and 72 hours ( < 0.05). In HTS, the MDSC varied, higher at 24 and 72 hours ( < 0.05), the M-MDSC/G-MDSC were continuously lower ( < 0.05). In the spleen, resuscitation with HTS, the M-MDSC/G-MDSC were continuously lower ( < 0.05). In BMNC, after resuscitation with HES, the M-MDSC/G-MDSC were lower at 24 and 72 hours ( < 0.05).

Conclusion: In mouse hemorrhagic shock model with bacterial infection, the resuscitation with NS, HTS, or HES induced difference changes in MDSC and M-MDSC/G-MDSC, which were time-dependent and organ-specific. Resuscitation with crystalloid, like NS or HTS, showed longer effects on the MDSC and M-MDSC/G-MDSC in peripheral blood; while HTS has a longer effect on M-MDSC/G-MDSC in the spleen, HES has a stronger impact on the differentiation regulation of MDSC to G-MDSC in the bone marrow.