Shock : molecular, cellular, and systemic pathobiological aspects and therapeutic approaches : the official journal the Shock Society, the European Shock Society, the Brazilian Shock Society, the International Federation of Shock Societies
-
Post-hemorrhagic shock mesenteric lymph is cytotoxic to endothelial cells and activates neutrophils.
The goal of these experiments was to test the hypothesis that after a nonlethal episode of hemorrhagic shock, factors carried in the mesenteric lymph would promote endothelial cell injury and activate neutrophils to a greater extent than portal vein plasma. Catheters were placed in the efferent lymphatic duct draining the mesenteric lymph node complex, after which male rats were subjected to sham or actual shock (30 mmHg for 90 min), and lymph was collected. Portal vein plasma was collected from the sham-shock and shocked rats at 6 h post-shock or sham-shock. ⋯ Lastly, neutrophil-mediated endothelial cell injury was potentiated by the presence of post-shock lymph, and the magnitude of HUVEC injury was greater in endothelial cells incubated with post-shock lymph plus neutrophils than in monolayers incubated with post-shock lymph or neutrophils alone. These results suggest that post-shock lymph is cytotoxic to endothelial cells and activates neutrophils. Since the lung is the first organ that is exposed to mesenteric lymph, lung injury after hemorrhagic shock may be mediated by factors contained in mesenteric lymph.
-
In septic patients, lipopolysaccharide (LPS) damages the vascular endothelium, which manifests as tissue edema and impaired healing. This pathology occurs when LPS distorts endothelial cell morphology partly by generating free radicals. A radioprotector that scavenges free radicals, the aminothiol WR-1065 ([N-2-mercaptoethyl]-1-3-diaminopropane) was found in a prior study to normalize the morphology of irradiated endothelial cells (Mooteri SN, Podolski JL, Drab EA, et al: Radiat Res 145:217-224, 1996). ⋯ Treatment with 2 mM WR-1065 for 2 h prior to LPS exposure attenuated the increased expression of alpha5beta1 and promoted cell-cell contact in the migrating endothelial cells. WR-1065 also promoted the retention of stress fibers and actin cytoskeletal shape in cells treated with LPS. Thus, LPS distorted endothelial cell morphology after increasing apical membrane expression of alpha5beta1 and dissipating stress fibers, effects prevented by WR-1065.
-
Lipopolysaccharide (LPS) is a primary agent of sepsis that damages the vascular endothelium. Endothelial cell proliferation is key to the repair of damaged endothelium, and drugs that counteract the antiproliferative impact of LPS on endothelial cells should be beneficial. Because LPS exerts much of its cytotoxicity by generating reactive oxygen and nitrogen intermediates, it would be helpful to know whether therapeutic antioxidant thiols maintain cell proliferation in injured endothelium. ⋯ The disulfide of WR-1065, WR-33278, was tested and shown to both promote DNA synthesis and inhibit apoptosis. The effectiveness of the disulfide suggests that the reduction of cytotoxicity does not necessarily result from the scavenging of free radicals. These findings demonstrate a novel role for aminothiols in promoting DNA synthesis and lowering apoptosis in endothelium injured with LPS.