Gut ischemia and reperfusion (IR), e.g. in small bowel transplantation or during resuscitation, may result in severe impairment of the intestinal microcirculation. Potential sequelae are mucosal damage, loss of intestinal barrier function, bacterial translocation, systemic inflammation, multiple organ failure and death. We hypothesized a protective role for extracellular adenosine signalling in intestinal IR injury. Using intravital microscopy we investigated the effects of the adenosine receptor (AR) agonist NECA (5'-N-ethyl carboxamide adenosine) on leukocyte-endothelial interactions and capillary perfusion in the intestinal microcirculation following intestinal IR. Six groups of Lewis rats (n = 44) were studied: control, NECA (5'-N-ethyl carboxamide adenosine), IR (30 minutes of intestinal ischemia, 2 hours of reperfusion), IR + NECA, IR + NECA + MRS1754 (A(2B)AR antagonist), IR + NECA + DPCPX (A(1)AR antagonist). All substances were administered i.v. immediately after declamping of the superior mesenteric artery. Intravital microscopy was performed after 2 hours of reperfusion. Following IR we observed a significant increase of leukocyte adhesion in the intestinal submucosal venules and a reduced capillary perfusion within the muscular layers. NECA reduced leukocyte activation and improved capillary perfusion significantly. Administration of A(2B)AR antagonist completely reversed the NECA effect, whereas A(1)AR inhibition only partially abolished the action of NECA. The data support the hypothesis that adenosine signalling is involved in intestinal IR injury. A(2B)AR may be more important than A(1)AR because A(2B)AR inhibition by MRS1754 completely reversed the effect of the adenosine receptor agonist NECA.
- MeSH
- krysa rodu rattus MeSH
- mikrocirkulace účinky léků MeSH
- modely nemocí na zvířatech MeSH
- potkani inbrední LEW MeSH
- purinergní receptory P1 genetika metabolismus MeSH
- reperfuzní poškození MeSH
- střeva krevní zásobení MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Intestinal microcirculatory disturbances play an important role in the pathophysiology of sepsis. A neural anti-inflammatory pathway has been suggested as a potential target for therapy that may dampen systemic inflammation. The aim of this study is to investigate the effects of physostigmine, a cholinesterase inhibitor, on the intestinal microcirculation and vascular contractility in experimental endotoxemia. Endotoxemia was induced in Lewis rats by intravenous lipopolysaccharide (LPS) administration. Animals were treated with either physostigmine or saline (control) following LPS challenge. The intestinal microcirculation, including leukocyte-endothelial interaction, functional capillary density (FCD) and non-perfused capillary density (NCD), was examined by intravital microscopy (IVM) 2 hours after LPS administration. The impact of physostigmine on vascular contractility of rat aortic rings was examined by in vitro myography. Physostigmine significantly reduced the number of adhering leukocytes in intestinal submucosal venules (V1 venules: -61%, V3 venules: -36%) of LPS animals. FCD was significantly increased by physostigmine treatment (circular muscle layer: +180%, longitudinal muscle layer: +162%, mucosa: +149%). Low concentrations of physostigmine produced significant contraction of aortic ring preparations, whereas high concentrations produced relaxation. In conclusion, physostigmine treatment significantly improved the intestinal microcirculation in experimental endotoxemia by reducing leukocyte adhesion and increasing FCD.
- MeSH
- cholinesterasové inhibitory aplikace a dávkování terapeutické užití MeSH
- endotoxemie metabolismus patofyziologie MeSH
- fysostigmin aplikace a dávkování terapeutické užití MeSH
- krysa rodu rattus MeSH
- mikrocirkulace účinky léků MeSH
- modely nemocí na zvířatech MeSH
- potkani inbrední LEW MeSH
- sepse MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Deletion of the cellular inhibitor of apoptosis protein 2 (cIAP2) is capable of rendering lipopolysaccharide (LPS)-activated macrophages highly susceptible to apoptotic triggers, thereby quickly eliminating the resident macrophage population soon after the initiation of a systemic inflammatory response. The aim of our study was to evaluate the impact of cIAP2 deletion on leukocyte recruitment and capillary perfusion in experimental endotoxemia and polybacterial sepsis using intravital microscopy of the intestinal microcirculation, which is crucial in the pathogenesis of septic multiple organ failure. We studied six groups of animals: wild-type (WT) control mice, cIAP2 knockout mice, endotoxemic WT mice (5 mg/kg LPS), endotoxemic cIAP2 knockouts (5 or 50 mg/kg LPS, respectively), and WT as well as knockout mice with polybacterial sepsis (colon ascendens stent peritonitis [CASP]). Intravital microscopy of the intestinal microcirculation was performed after 1 h of endotoxemia or 12 h of CASP-induced sepsis, respectively. Intestinal microvascular blood flow was measured using laser Doppler flowmetry. After 1 h of endotoxemia (5 mg/kg LPS), we observed a significant increase of leukocyte adhesion in intestinal submucosal venules of WT mice in comparison with control animals. The cIAP2 knockout mice showed a significant reduction in leukocyte recruitment within the intestinal submucosal microvasculature after 5 or 50 mg/kg LPS challenge, respectively. Lipopolysaccharide-induced decrease in intestinal microvascular blood flow was not affected by cIAP2 inhibition. In CASP-induced sepsis, cIAP2 deletion had no effect on intestinal leukocyte recruitment. Deletion of cIAP2 resulted in reduced microvascular leukocyte recruitment within the intestinal microcirculation in endotoxemia but not in polybacterial sepsis.
- MeSH
- endotoxemie genetika metabolismus patofyziologie MeSH
- inhibitory apoptózy genetika metabolismus MeSH
- mikrocirkulace genetika fyziologie MeSH
- modely nemocí na zvířatech MeSH
- myši inbrední C57BL MeSH
- myši knockoutované MeSH
- myši MeSH
- sepse genetika metabolismus patofyziologie MeSH
- střeva krevní zásobení MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH