International journal of microcirculation, clinical and experimental最新文献

{"title":"Effect of hepatic nerve stimulation and norepinephrine on the laser Doppler flux signal from the surface of the perfused rat liver.","authors":"A M Wheatley,&nbsp;N E Almond","doi":"10.1159/000179206","DOIUrl":"https://doi.org/10.1159/000179206","url":null,"abstract":"<p><p>The effect of hepatic nerve stimulation and norepinephrine (NE) on the laser Doppler signal from the surface of the perfused rat liver was tested. The livers from male Wistar rats were perfused in situ via the portal vein with Krebs-Henseleit buffer containing 20% bovine erythrocytes (37 degrees C, pH 7.4) and total liver blood flow (TLBF) was by timed collection of effluent. Portal vascular resistance (PVR) was calculated from the pressure difference across the liver. Linearity of laser Doppler flowmetry (LDF) with TLBF was confirmed in all preparations. Stimulation of the hepatic nerves (2 ms, 20 V) was performed at frequencies between 0.5 and 20 Hz (n = 11). NE was added to the buffer at concentrations between 10(-10) and 10(-6) M (n = 8). A stimulus-dependent rise in PVR occurred during hepatic nerve stimulation (basal, 3.11 +/- 0.26 dyn s cm-5) and NE administration (basal, 2.62 +/- 0.29 dyn s cm-5), with a maximum effect at 20 Hz (311 +/- 45%) and 10(-6) M (591 +/- 72%), respectively. Both LDF and TLBF fell during nerve stimulation and NE. A linear relationship (r = 0.99; p < 0.001) between change in TLBF (%) and LDF flux (%) was found for NE (10(-10) to 10(-6) M). During nerve stimulation, the fall in TLBF and LDF flux was linear with the logarithm of stimulus frequency and reached a maximum at 10 and 20 Hz, respectively. At a stimulus frequency of 20 Hz, the change in LDF was significantly different from the change in TLBF (p < 0.001). We conclude from our findings that during high-frequency hepatic nerve stimulation, LDF underestimates TLBF.</p>","PeriodicalId":14035,"journal":{"name":"International journal of microcirculation, clinical and experimental","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1997-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1159/000179206","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"20123429","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Postischemic leukocyte/endothelial cell interactions and microvascular barrier dysfunction in skeletal muscle: cellular mechanisms and effect of Daflon 500 mg.","authors":"R J Korthuis,&nbsp;D C Gute","doi":"10.1159/000179261","DOIUrl":"https://doi.org/10.1159/000179261","url":null,"abstract":"<p><p>A growing body of evidence indicates that neutrophils play a critical role in disrupting the microvascular barrier in skeletal muscle. Recent studies from our laboratory and by others indicate that administration of antibodies directed against P-selectin, ICAM-1, or the common subunit (CD18) of CD11/CD18 was as effective as neutrophil depletion in attenuating ischemia/reperfusion (I/R)-induced microvascular barrier disruption and edema formation in skeletal muscle. These studies have important implications with regard to the pathogenesis of leg ulceration in view of our more recent work indicating that the increase in tissue pressure induced by edema formation secondary to microvascular barrier disruption may lead to the development of capillary no-reflow. The resulting maldistribution of blood flow during reperfusion exacerbates muscle injury induced by ischemia. Daflon 500 mg is a purified, micronized flavonoid fraction that exhibits a number of anti-inflammatory properties and is used clinically to treat venous insufficiency. In view of these actions and the demonstrated role of neutrophil adhesion in the pathogenesis of I/R, we sought to determine whether this agent would prevent leukocyte adhesion and microvascular barrier disruption in postischemic rat cremaster muscles and small bowel. Rats were treated with Daflon 500 mg (80 mg/kg/day by gavage) or its vehicle for 2 (cremaster studies) or 10 (mesenteric studies) days prior to the experiments. Leukocyte/endothelial cell interactions and venular protein leakage were quantitated using intravital microscopic techniques in rat cremaster muscles and mesenteries subjected to ischemia (60 min for cremaster, 20 min for mesentery) and reperfusion (60 min). The results indicated that Daflon 500 mg was as effective as the anti-adhesive monoclonal antibodies in reducing postischemic leukocyte adhesion and emigration and venular protein leakage in these models.</p>","PeriodicalId":14035,"journal":{"name":"International journal of microcirculation, clinical and experimental","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1997-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1159/000179261","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"20401385","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Subject Index Vol. 17, 1997","authors":"Shiro Kato, N. Ohnuma, K. Ohno, Keijirou Takasaki, S. Okamoto, Toshihiko Asai, M. Okuda, T. Nakamoto, M. Iizuka, A. R. Firestone, A. Wheatley, U. Thüer, K. Norrby, P. Østergaard, A. Harris, R. Hecht, F. Peer, D. Nolte, K. Messmer, H. Axelsson, U. Bagge, K. Lundholm, E. Svanberg, E. Wahlberg, L. Enochsson, J. V. Beek, H. Schmid-schönbein, S. Ziege, R. Grebe, V. Blazek, R. Spielmann, F. Linzenich, G. Siegel, M. Malmsten, D. Klüßendorf, H. Hofer, F. Christ, J. Abicht, M. Athelogou, H. Basehnegger, M. Niklas, Klaus Peter, S. Zige, E. Martin, G. Janssen, G. Tangelder, M. Egbrink, R. Reneman","doi":"10.1159/000179256","DOIUrl":"https://doi.org/10.1159/000179256","url":null,"abstract":"","PeriodicalId":14035,"journal":{"name":"International journal of microcirculation, clinical and experimental","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1997-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88820863","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Microcirculation and Leg Ulcers","authors":"Philip D. Smith","doi":"10.1159/000179257","DOIUrl":"https://doi.org/10.1159/000179257","url":null,"abstract":"Dr. Philip Coleridge Smith, Department of Surgery, Middlesex Hospital, Mortimer Street, London W1N 8AA (UK), Tel. +44 171 3809412, Fax +44 171 3809413, E-Mail p.coleridgesmith@ucl.ac.uk Venous diseases of the lower limb are very common, with a prevalence of 10-20% of the adult population, and in Europe drugs are widely used to treat these. Many of these drugs were developed and used without detailed knowledge of their mechanisms of action. Recent research has uncovered many details of the biological processes at work in blood vessels. This had lead to a revolution in the understanding of ischaemia and atheroma formation. It has been found that many of the mechanisms responsible for ischaemia reperfusion injury are also involved in the development of skin damage and ulceration in patients with chronic venous disease of the leg. The symposium included in the pages that follow was originally presented to the Vlth World Microcirculation Congress in Munich on 29th August 1996. The articles in it review the effect of a widely used phlebotropic drug. Daflon® 500 mg, on several models of tissue ischaemia. The animal models selected are well known and widely used in the study of ischaemia as well as in testing various interventions to protect against ischaemia reperfusion injury. The data show that there is a substantial, easily measurable effect of Daflon 500 on endothelial-leucocyte interactions caused by ischaemia reperfusion injury. These are similar to the effects of some well-known methods of preventing endothelial injury, such as the use of antibodies to the leucocyte ligand CD1 lb. These are certainly interesting and unexpected findings. The severity of ischaemia reperfusion injury is generally very great and important cellular mechanisms must be inhibited to modify this process. It is fascinating to see that Daflon 500 has the ability to achieve measurable effects in such models. Tissue damage caused by venous disease is usually more insidious, slowly destroying the endothelium of the skin microcirculation in the leg over a number of years. However, it is now clear that many of the same processes are at work in patients with ambulatory venous hypertension to produce damage in the skin microcirculation. It would be very interesting to discover whether Daflon 500 could modify the same mechanisms in patients with venous disease. Clearly different methods of investigation would be required, but such studies would confirm the reasons for the efficacy of Daflon 500 in the management of venous disease. The last two papers in this symposium discuss the results of treatment in 2 different groups of patients. In neither group has the leucocyte response been assessed in detail, although a number of rheological factors have been measured by Dr. Le Dévéhat. He investigated a group of patients with mild venous symptoms and recorded a small influence of Daflon 500 on the parameters he investigated. In contrast Prof. Nicolaides reports the efficacy of Daflon 500","PeriodicalId":14035,"journal":{"name":"International journal of microcirculation, clinical and experimental","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1997-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89821691","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Pathophysiology of venous leg ulceration.","authors":"A Dormandy","doi":"10.1159/000179258","DOIUrl":"https://doi.org/10.1159/000179258","url":null,"abstract":"<p><p>The currently favoured hypothesis for the link between the raised venous pressure of chronic venous insufficiency and venous ulceration is based on the intermittent inappropriate activation of white blood cells. The damage initiated by the oxidative burst of the leucocyte leads to endothelial dysfunction, interstitial oedema, microthrombi and long-term microcirculatory damage including decreased capillary density. The net result is impairment of the potential for healing and hence ulceration.</p>","PeriodicalId":14035,"journal":{"name":"International journal of microcirculation, clinical and experimental","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1997-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1159/000179258","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"20401383","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of Daflon 500mg on postischemic macromolecular leak syndrome in striated skin muscle of the hamster.","authors":"D Nolte,&nbsp;S Pickelman,&nbsp;E Schütze,&nbsp;M Möllmann,&nbsp;K Messmer","doi":"10.1159/000179259","DOIUrl":"https://doi.org/10.1159/000179259","url":null,"abstract":"<p><p>We have recently shown that the purified micronized flavonoid fraction (90% diosmin and 10% hesperidin) Daflon 500 mg attenuates reperfusion injury in the striated skin muscle of the hamster. Herein, we report on the action of Daflon 500 mg on postischemic macromolecular leakage of FITC-dextran 150 kD provoked by tourniquet ischemia. Intravital fluorescence microscopy was used for analysis of macromolecular leakage in the microcirculation model of the hamster. A tourniquet ischemia of 4 h duration was induced followed by reperfusion. Animals were treated by gavage of Daflon 500 mg (n = 6) for 8 days at a daily dose of 30 mg kg(-1) body weight. Control animals received equivalent volumes of the vehicle (5% Arabic gum solution, n = 6). Measurements of the microcirculatory parameters were made before induction of ischemia and at 0.5, 2 and 24 h of reperfusion. After induction of ischemia, macromolecular leakage from postcapillary venules was significantly enhanced in vehicle-treated animals. Treatment with Daflon 500 mg significantly attenuated macromolecular leakage of FITC-dextran 150 kD. Preliminary data from a histomorphometric analysis (n = 3/experimental group) indicated that the number of emigrated (extravascular) leukocytes after ischemia reperfusion was markedly reduced in Daflon 500 mg-treated animals as compared to controls. These data indicate that Daflon 500 mg prevents leakage of the macromolecular tracer FITC-dextran 150 kD from postcapillary venules after postischemic reperfusion, presumably through an inhibitory action on the emigration of activated leukocytes.</p>","PeriodicalId":14035,"journal":{"name":"International journal of microcirculation, clinical and experimental","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1997-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1159/000179259","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"20401384","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Contents, Vol. 17, 1997","authors":"Shiro Kato, N. Ohnuma, K. Ohno, Keijirou Takasaki, S. Okamoto, Toshihiko Asai, M. Okuda, T. Nakamoto, M. Iizuka, A. R. Firestone, A. Wheatley, U. Thüer, K. Norrby, P. Østergaard, A. Harris, R. Hecht, F. Peer, D. Nolte, K. Messmer, H. Axelsson, U. Bagge, K. Lundholm, E. Svanberg, E. Wahlberg, L. Enochsson, J. V. Beek, H. Schmid-schönbein, S. Ziege, R. Grebe, V. Blazek, R. Spielmann, F. Linzenich, G. Siegel, M. Malmsten, D. Klüßendorf, H. Hofer, F. Christ, J. Abicht, M. Athelogou, H. Basehnegger, M. Niklas, Klaus Peter, S. Zige, E. Martin, G. Janssen, G. Tangelder, M. Egbrink, R. Reneman","doi":"10.1159/000179241","DOIUrl":"https://doi.org/10.1159/000179241","url":null,"abstract":"","PeriodicalId":14035,"journal":{"name":"International journal of microcirculation, clinical and experimental","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1997-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82039845","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Semi-invasive laser-Doppler flowmetry technique. New application for recordings of hemodynamics in combination with manometry of human small intestine.","authors":"M Thollander,&nbsp;P M Hellström,&nbsp;B Gazelius","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>A small-bowel manometry tube was supplied with two single-fiber microprobes, which recorded blood flow in the proximal small intestine by the laser-Doppler flowmetry (LDF) technique. In all experiments, saline was infused intravenously as control during the first migrating motor complex (MMC) cycle, and a drug or another saline control given intravenously during the second MMC cycle. Recordings were performed during phase 1 of MMC, i.e. when motor pattern showed quiescence. Adrenaline increased blood perfusion values by 140% in proximal duodenum and 95% in distal duodenum. The alpha 2-adrenoceptor agonist clonidine decreased the corresponding values by 34 and 25%, respectively, while oxymetazoline decreased perfusion by 33 and 44% at the same levels. The beta-adrenoceptor agonist isoprenaline increased blood perfusion values by 172% in the proximal duodenum and 194% in the distal duodenum, whereas the antagonist propranolol decreased the corresponding values by 45 and 52%, respectively. In a separate group of subjects, propranolol was given after adrenaline. The increase in blood perfusion regularly seen after adrenaline was blocked after propranolol administration. In conclusion, our findings validate semi-invasive LDF technique for studies of hemodynamics in human small intestine under basal motor conditions and in drug-induced blood flow changes.</p>","PeriodicalId":14035,"journal":{"name":"International journal of microcirculation, clinical and experimental","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1997-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"20123525","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Correlation between the uptake of sodium fluorescein in the tissue and xenon-133 clearance and laser Doppler fluxmetry in measuring changes in skin circulation.","authors":"E Proano,&nbsp;L Svensson,&nbsp;L Perbeck","doi":"10.1159/000179202","DOIUrl":"https://doi.org/10.1159/000179202","url":null,"abstract":"<p><p>We have measured the plantar forefoot skin circulation by the uptake of sodium fluorescein (fluorescein flowmetry), 133Xe clearance and laser Doppler fluxmetry in 24 healthy subjects and correlated measurements under basal conditions and after provocation by alcohol intake and application of external heat. To assess the change in skin circulation between the initial measurement at rest and the second measurement after provocation, the coefficient of correlation (r) of the fluorescein flowmetry to the fast slope of the 133Xe elimination curve was 0.46 (p < 0.05), to the slow slope of the 133Xe elimination curve 0.66 (p < 0.001) and to laser Doppler fluxmetry 0.86 (p < 0.001). The coefficient of correlation (r) of the fluorescence appearance time to fluorescein flowmetry was 0.65 (p < 0.001), to the fast slope of the 133Xe elimination curve 0.14 (p = 0.42), to the slow slope of the 133Xe elimination curve 0.47 (p < 0.05) and to laser Doppler fluxmetry 0.63 (p < 0.001). The uptake of sodium fluorescein as measured by fluorescein fluxmetry correlates well with both 133Xe clearance and laser Doppler fluxmetry in assessing a change in skin circulation in healthy humans. The fluorescence appearance time also correlates to the slow slope of the 133Xe elimination curve and to laser Doppler fluxmetry though to a lesser extent.</p>","PeriodicalId":14035,"journal":{"name":"International journal of microcirculation, clinical and experimental","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1997-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1159/000179202","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"20123549","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Semi-Invasive Laser-Doppler Flowmetry Technique","authors":"M. Thollander, P. Hellström, B. Gazelius","doi":"10.1159/000179201","DOIUrl":"https://doi.org/10.1159/000179201","url":null,"abstract":"A small-bowel manometry tube was supplied with two single-fiber micro-probes, which recorded blood flow in the proximal small intestine by the laser-Doppler flowmetry (LDF) technique. In all experimen","PeriodicalId":14035,"journal":{"name":"International journal of microcirculation, clinical and experimental","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1997-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82235760","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}