Reduced rate of bacterial translocation and improved variables of natural killer cell and T-cell activity in rats surviving controlled hemorrhagic shock and treated with hypertonic saline.
OBJECTIVE
To examine the effect of hypertonic saline on bacterial translocation and the number and function of natural killer and T cells in controlled hemorrhagic shock.


METHODS
Randomized controlled study. Duration of follow-up was 24 hrs.


METHODS
University research laboratory.


METHODS
Adult male Sprague-Dawley rats, weighing 310-390 g.


METHODS
Controlled hemorrhagic shock was induced by blood withdrawal (mean arterial pressure, 30-40 mm Hg) and maintained for 30 mins. The animals were randomly divided into three groups: group 1 (n = 10) was sham-operated, group 2 (n = 10) was untreated, and group 3 was treated with 5 mL/kg hypertonic saline (n = 10). The rats were killed after 24 hrs.


RESULTS
Infusion of hypertonic saline in group 3 was followed by reduced bacterial translocation rate (5.0 +/- 2.2% vs. 18.3 +/- 5.3%, p <.033). The total mass of bacteria isolated from hypertonic saline-treated animals with bacterial translocation was 7.8- to 10.4-fold less than that from untreated rats. Controlled hemorrhagic shock resulted in a low percentage of CD4+ cells in blood (35.2 +/- 3.9%, p <.05) and lymph nodes (44.4 +/- 4.5%, p <.05) and depressed CD4 expression on blood (82 +/- 13 arbitrary units, p <.005) and lymph node (168 +/- 24 arbitrary units, p <.03) cells. A compensatory mobilization of NKR-P1+ cells from lymph nodes (8.6 +/- 2.3%, p <.05) to blood (21.2 +/- 5.2%, p <.01) with down-regulated NKR-P1 expression on blood cells (59 +/- 10 arbitrary units, p <.005) was observed. Natural killer cell-mediated cytotoxicity was decreased (67.9 +/- 9.7%, p <.05). Hypertonic saline treatment greatly stimulated CD4 expression on blood (419 +/- 113 arbitrary units, p <.005) and lymph node (553 +/- 115 arbitrary units, p <.03) cells. Also, normalization of NKR-P1 expression (160 +/- 19 arbitrary units, p <.005) and restoration of natural killer cell-mediated cytotoxicity to near normal values (88.6 +/- 7.4%, p <.05) were demonstrated.


CONCLUSIONS
Controlled hemorrhagic shock was accompanied by CD4+ cells suppression and excessive recruitment of natural killer cells with abnormally low NKR-P1 expression and suppressed cytolytic activity into circulation. Infusion of hypertonic saline reversed these changes and reduced bacterial translocation.
Hirsh
Mark
M
Laboratory for Shock and Trauma Research and the Department of General Surgery, the B. Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel.
Dyugovskaya
Larissa
L
Bashenko
Yulia
Y
Krausz
Michael M
MM
D000818:Animals; D018988:Bacterial Translocation / Q000502:physiology*; D018791:CD4 Lymphocyte Count; D007694:Killer Cells, Natural / Q000276:immunology*; D008198:Lymph Nodes; D008297:Male; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley; D012462:Saline Solution, Hypertonic / Q000627:therapeutic use*; D012771:Shock, Hemorrhagic / Q000188:drug therapy* / Q000276:immunology* / Q000382:microbiology; D013601:T-Lymphocytes / Q000276:immunology*
D012462:Saline Solution, Hypertonic