Glucosamine administration during resuscitation improves organ function after trauma hemorrhage

Stress-induced hyperglycemia is necessary for maximal rates of survival after severe hemorrhage; however, the responsible mechanisms are not clear. One consequence of hyperglycemia is an increase in hexosamine biosynthesis, which leads to increases in levels of O-linked attachment of N-acetyl-glucosamine (O-GIcNAc) on nuclear and cytoplasmic proteins. This modification has been shown to lead to improved survival of isolated cells after stress. In view of this, we hypothesized that glucosamine (GIcNH(2)), which more selectively increases the levels of O-GIcNAc administration after shock, will have salutary effects on organ function after trauma hemorrhage (TH). Fasted male rats that underwent midline laparotomy were bled to a mean arterial blood pressure of 40 mmHg for 90 min and then resuscitated with Ringer lactate (tour times the shed blood volume). Administration of 2.5 mL of 150 mmol L-1 GIcNH(2) midway during resuscitation improved cardiac output 2-fold compared with controls that received 2.5 mL of 150 mmol L-1 NaCl. GIcNH(2) also improved perfusion of various organs systems, including kidney and brain, and attenuated the TH-induced increase in serum levels of IL-6 (902 +/- 224 vs. 585 +/- 103 pg mL(-1)) and TNF-alpha (540 +/- 81 vs. 345 +/- 110 pg mL(-1)) (values are mean SD). GIcNH(2) administration resulted in significant increase in protein-associated O-GIcNAc in the heart and brain after TH. Thus, GIcNH2 administered during resuscitation improves recovery from TH, as assessed by cardiac function, organ perfusion, and levels of circulating inflammatory cytokines. This protection correlates with enhanced levels of nucleocytoplasmic protein O-GIcNAcylation and suggests that increased O-GIcNAc could be the mechanism that links stress-induced hyperglycemia to improved outcomes.