Regional differences in lymphocyte function following resuscitated hemorrhagic shock

Although it is well known that hemorrhagic shock causes immunosuppression, there have been few attempts to define these changes in the various immune compartments. Accordingly, male rats were bled into severe hemorrhagic shock for 60 minutes (mean arterial pressure 35 +/- 5 mm Hg). Twenty-four hours following resuscitation, splenic, mesenteric, and peripheral lymphocytes were harvested for cell population analysis and mitogen stimulation assays. Cell marker analysis revealed no changes in B-cell or T-cell subpopulations in any immune compartment after shock. The splenic and peripheral lymphocytes showed marked depression of mitogen-induced stimulation after shock. In contrast, mesenteric lymphocyte responses to both T-cell and B-cell mitogens were not depressed after shock. Regional variability in mitogen responses after shock occur without change in B-cell or T-cell subpopulations in any immune compartment tested. The mechanism or mechanisms involved warrant further investigation.