Abstract 2084: Protein O-Glycosylation Improves Survival and Effects Cytokine Release Following Trauma-Hemorrhage in Rats
We have previously shown that glucosamine treatment during resuscitation improved cardiac output and organ perfusion following trauma-hemorrhage (TH) in rats and increased levels of N-acetyl-glucosamine (O-GlcNAc) on proteins. Therefore, we hypothesized that increased protein O-GlcNAc levels would both increase survival in the absence of resuscitation and attenuate cytokine release 24 hours following TH and resuscitation (THR). In the survival study soft tissue trauma was induced in 37 male rats and 55% of total blood volume was removed over 25 minutes. At the end of TH period, 1.25 mmoles/kg b.w. glucosamine or equivalent mannitol (control) dissolved in 2 mL vehicle was injected i.v. over 10 minutes and rats were monitored for 2 hours. In the cytokine study 11 rats were subjected to similar TH and following blood withdrawal 1 mmoles/kg b.w. glucosamine, or mannitol was injected and mean arterial pressure maintained at 35– 40 mmHg for 45 minutes. Animals were resuscitated using 4X the withdrawn blood volume with sodium-chloride containing 2 mmoles/kg b.w. glucosamine, or mannitol and were euthanized 24 hours later. Serum GM-CSF, MCP-1, IL-1a, IL1b, IL-2, IL-6, IL-10, TNF-α and IFN-γ were measured at baseline and 24 hours following resuscitation. Glucosamine treatment increased survival rate 2 hours following hemorrhage without resuscitation, compared with the control (47% vs. 20%, p< 0.05) and O-GlcNAc levels were significantly elevated in heart, brain and liver. Glucosamine also increased the serum levels of anti-inflammatory cytokine IL-10 (7.7±2.6 pg/mL vs. 21.9±6.8 pg/mL, p<0.05) 24 hours after THR but had no effect on other cytokines. PUGNAc an inhibitor of O-GlcNAcase also increases tissue O-GlcNAc levels and when 25 μmol/kg b. w. was administered during resuscitation the serum level of both major pro-inflammatory cytokine IL-6 (145±41 pg/mL vs. 38±6 pg/mL, p<0.05) and TNF-α (24.1±5.41 pg/mL vs. undetectable) were significantly lower compared to the control 24hrs after THR. In conclusion, protein O-glycosylation may be beneficial in the treatment of hypovolemia and prevention of systemic inflammatory response syndrome. However, the different cytokine pattern after glucosamine and PUGNAc treatment requires further studies.