Search results for "intravital microscopy"

C1-ESTERASE INHIBITOR REVERSES FUNCTIONAL CONSEQUENCES OF SUPERIOR MESENTERIC ARTERY ISCHEMIA/REPERFUSION BY LIMITING REPERFUSION INJURY AND RESTORIN…

2006

Activated complement contributes significantly to reperfusion injury after ischemia. This study explores functional consequences of C1-esterase inhibitor (C1-INH) treatment after superior mesenteric artery occlusion (SMAO)/ reperfusion using intravital microscopy. Thirty anesthetized, spontaneously breathing, male Sprague-Dawley rats underwent SMAO for 60 min followed by reperfusion (4 h). C1-esterase inhibitor (100 and 200 IU/kg body weight) or saline (0.9%) was given as a single bolus before reperfusion. Sham-operated animals (n = 10) without SMAO served as controls.Systemichemodynamicsweremonitoredcontinuously,arterial bloodgasesanalyzedintermittently, andleukocyte/ endothelial interacti…

Expanding Two-Photon Intravital Microscopy to the Infrared by Means of Optical Parametric Oscillator

2010

Chronic inflammation in various organs, such as the brain, implies that different subpopulations of immune cells interact with the cells of the target organ. To monitor this cellular communication both morphologically and functionally, the ability to visualize more than two colors in deep tissue is indispensable. Here, we demonstrate the pronounced power of optical parametric oscillator (OPO)-based two-photon laser scanning microscopy for dynamic intravital imaging in hardly accessible organs of the central nervous and of the immune system, with particular relevance for long-term investigations of pathological mechanisms (e.g., chronic neuroinflammation) necessitating the use of fluorescent…

Automated Measurement of Microcirculatory Blood Flow Velocity in Pulmonary Metastases of Rats

2014

Because the lung is a major target organ of metastatic disease, animal models to study the physiology of pulmonary metastases are of great importance. However, very few methods exist to date to investigate lung metastases in a dynamic fashion at the microcirculatory level, due to the difficulty to access the lung with a microscope. Here, an intravital microscopy method is presented to functionally image and quantify the microcirculation of superficial pulmonary metastases in rats, using a closed-chest pulmonary window and automated analysis of blood flow velocity and direction. The utility of this method is demonstrated to measure increases in blood flow velocity in response to pharmacologi…

Intravital Microscopy for Measuring Microcirculatory Blood Flow in Pulmonary Surface Metastases of Rats

2015

Nitric oxide, derived from inducible nitric oxide synthase, decreases hypoxia inducible factor-1α in macrophages during aspirin-induced mesenteric in…

2010

Background and purpose:  Nitric oxide (NO) modulates expression of hypoxia inducible factor-1 (HIF-1), a transcription factor regulating function of myeloid cells. Here, we have assessed the role played by NO, formed by inducible NOS (iNOS), in the inflammation induced by aspirin in the gut, by modulating HIF-1 activity. Experimental approach:  The role of iNOS-derived NO on leucocyte–endothelial interactions induced by aspirin was evaluated by intravital microscopy in mesenteric venules of rats pretreated with selective iNOS inhibitors, 1400W or l-N6-(1-iminoethyl)-lysine. NO was localized by fluorescence microscopy, using DAF-FM. iNOS, HIF-1α and CD36 were localized by immunohistochemistr…

Mechanisms of gastroprotection by transdermal nitroglycerin in the rat

1999

Nitric oxide (NO) donors prevent experimentally-induced gastric mucosal damage, but their clinical utility is limited by short duration of action or unsuitability of the pharmaceutical form employed. This study analyses the gastroprotection elicited by a clinically used mode of continuous administration of an NO donor, namely the nitroglycerin patch. Application to rats of a transdermal patch that releases doses of nitroglycerin comparable to those used in man (40, 80, 160 and 400 ng min(-1) rat(-1)) reduced gastric damage induced by indomethacin (25 mg kg(-1), p.o. or s.c.). The nitroglycerin patch (160 ng min(-1) rat(-1)) also diminished damage by oral administration (1 ml) of acidified b…

Rolipram inhibits leukocyte-endothelial cell interactionsin vivothrough P- and E-selectin downregulation

2002

1. Rolipram, a selective phosphodiesterase (PDE) type 4 inhibitor, was used to characterize leukocyte recruitment mechanisms in models of acute and subacute inflammation. Intravital microscopy within the rat mesenteric microcirculation was employed. 2. Mesentery superfusion with PAF (0.1 microM) induced a significant increase in leukocyte rolling flux, adhesion and emigration at 60 min. Rolipram pretreatment, markedly inhibited these parameters by 100, 95 and 95% respectively. 3. Similar effects were observed when the mesentery was superfused with LPS (1 microg ml(-1)) for the same time period and these leukocyte parameters were nearly abrogated by rolipram pretreatment. 4. LPS exposure of …

A small molecule, orally active, α 4 β 1 /α 4 β 7 dual antagonist reduces leukocyte infiltration and airway hyper-responsiveness in an experimental m…

2006

α4β1 and α4β7 integrins are preferentially expressed on eosinophils and mononuclear leukocytes and play critical roles in their recruitment to inflammatory sites. We investigated the effects of TR14035, a small molecule, α4β1/α4β7 dual antagonist, in a rat model of allergic asthma. Actively sensitized rats were challenged with aerosol antigen or saline on day 21, and the responses evaluated 24 and 48-h later. TR14035 (3 mg kg−1, p.o.) was given 1-h before and 4-h after antigen or saline challenge. Airway hyper-responsiveness to intravenous 5-hydroxytryptamine was suppressed in TR14035-treated rats. Eosinophil, mononuclear cell and neutrophil counts, and eosinophil peroxidase and protein con…

Cyclic AMP elevating agents and nitric oxide modulate angiotensin II-induced leukocyte-endothelial cell interactionsin vivo

2001

Angiotensin (Ang-II) is a key molecule in the development of cardiac ischaemic disorders and displays proinflammatory activity in vivo. Since intracellular cyclic nucleotides elevating agents have proved to be effective modulators of leukocyte recruitment, we have evaluated their effect on Ang-II-induced leukocyte-endothelial cell interactions in vivo using intravital microscopy within the rat mesenteric microcirculation. Pretreatment with iloprost significantly inhibited (1 nM) Ang-II-induced increase in leukocyte rolling flux, adhesion and emigration at 60 min by 96, 92 and 90% respectively, and returned leukocyte rolling velocity to basal levels. Pretreatment with salbutamol or co-superf…

Dynamic deformation of migratory efferent lymph-derived cells ?trapped? in the inflammatory microcirculation

2002

The cellular immune response depends on the delivery of lymphocytes from the lymph node to the peripheral site of antigenic challenge. During their passage through the inflammatory microcirculaton, the migratory cells can become transiently immobilized or "trapped" in small caliber vessels. In this report, we used intravital microscopy and temporal area mapping to define the dynamic deformation of efferent lymph-derived mononuclear cells trapped in the systemic inflammatory microcirculation. Mononuclear cells obtained from the efferent lymph draining the oxazolone-stimulated microcirculation were labeled with fluorescent dye and reinjected into the feeding arterial circulation. Intravital v…