endothelin-1 and Femoral-Fractures

Sepsis remains a serious complication after trauma. Although hepatic microvascular dysfunction occurs during trauma and sepsis, the mechanism responsible is unclear. Since Kupffer cells can provide the signals that regulate the hepatic response in inflammation and contribute to multiple organ failure, this study investigated the role of Kupffer cells in the imbalance of the expression of vasoactive and inflammatory mediators during trauma and sepsis.. The Kupffer cells were inactivated by gadolinium chloride (GdCl(3), 7.5 mg/kg body weight, i.v.) 1 and 2 d before surgery. The animals then underwent femur fracture (FFx) followed 48 h later by cecal ligation and puncture (CLP). After 24 h, blood was obtained to determine the alanine aminotransferase (ALT) activity. Liver samples were also taken for RT-PCR analysis of the mRNA for genes of interest.. Serum ALT levels increased in FFx and CLP. This increase was potentiated by FFx + CLP and was attenuated by GdCl(3). The mRNA expression levels in the FFx showed no change in the ET(A), ET(B), iNOS, and HO-1, and showed a slight increase of 2.6-fold, 2.2-fold, and 2.8-fold for ET-1, eNOS, and TNF-alpha, respectively. The ET-1 mRNA expression level increased after CLP and FFx + CLP. The ET(A) mRNA level showed no change, whereas the ET(B) transcripts increased after CLP. This increase was potentiated after FFx + CLP, and was attenuated by GdCl(3). After CLP alone, iNOS, eNOS, and TNF-alpha mRNA expression levels were increased 20.3-fold, 5.8-fold, and 11.9-fold, respectively. This increase was potentiated after FFx + CLP, and was attenuated by GdCl(3). HO-1 mRNA expression significantly increased after FFx + CLP, and this increase was attenuated by GdCl(3).. Mild trauma alone causes little change in the expression of vasoactive mediators while sequential injury potentiates the imbalanced gene expression induced by sepsis. Kupffer cells might be essential for hepatic microvascular dysfunction after sequential stress.

Topics: Alanine Transaminase; Animals; Endothelin-1; Femoral Fractures; Gadolinium; Heme Oxygenase (Decyclizing); Kupffer Cells; Liver Circulation; Male; Nitric Oxide Synthase Type II; Rats; Rats, Sprague-Dawley; Receptor, Endothelin A; Receptor, Endothelin B; RNA, Messenger; Sepsis; Tumor Necrosis Factor-alpha

Macrophages undergo maladaptive alterations after trauma. In this study, we assessed the role of Kupffer cells in hepatic microcirculatory response to endothelin-1 (ET-1) after femur fracture (FFx) and cecal ligation and puncture (CLP).. Sprague-Dawley rats (200-300 g) underwent sham, FFx, CLP, or FFx + CLP. To ablate Kupffer cells, group 1 animals were treated with gadolinium chloride, and group 2 animals received saline. Hepatic microcirculation was assessed by intravital microscopy. Liver mitochondrial redox state and tissue oxygen (tPo2) were determined by NADH and ruthenium fluorescence, respectively. Liver damage was estimated by alanine aminotransferase levels. Differences were assessed using analysis of variance followed by Student-Newman-Keuls post hoc test.. After 10 minutes of ET-1, CLP and FFx + CLP caused significant reduction in hepatic perfusion index (2.5-fold and 5-fold vs. sham, p < 0.05, respectively), redox state (36% and 45% vs. sham, p < 0.01, respectively), tPo2 (10% and 12% vs. sham, p < 0.05, respectively), and more liver damage compared with sham and FFx-treated animals. Kupffer cell depletion restored microcirculation, redox state, and tPo2 and abrogated hepatocellular damage.. Kupffer cells contribute directly to hepatic microcirculatory dysfunction and liver injury after inflammatory stress. Furthermore, Kupffer cell depletion ameliorates the microcirculatory perturbations of trauma and sepsis. Thus, modulation of Kupffer cell response may prove beneficial.

Topics: Animals; Cecum; Endothelin-1; Femoral Fractures; Ferrous Compounds; Kupffer Cells; Ligation; Liver; Liver Circulation; Male; Microcirculation; NAD; Rats; Rats, Sprague-Dawley; Sepsis