Selectins and beta(2)-integrins mediate post-ischaemic venular adhesion ofpolymorphonuclear leukocytes, but not capillary plugging, in isolated hearts

Citation
H. Habazettl et al., Selectins and beta(2)-integrins mediate post-ischaemic venular adhesion ofpolymorphonuclear leukocytes, but not capillary plugging, in isolated hearts, PFLUG ARCH, 438(4), 1999, pp. 479-485
Citations number
31
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Physiology
Journal title
PFLUGERS ARCHIV-EUROPEAN JOURNAL OF PHYSIOLOGY
ISSN journal
0031-6768 → ACNP
Volume
438
Issue
4
Year of publication
1999
Pages
479 - 485
Database
ISI
SICI code
0031-6768(199909)438:4<479:SABMPV>2.0.ZU;2-1
Abstract
Leukocytes adhering to venular endothelium and emigrating into the tissue c ontribute to myocardial reperfusion injury. The aim of the present study wa s to characterize the contribution of two different families of adhesion mo lecules, selectins and integrins, to post-ischaemic capillary plugging and venular adhesion of leukocytes in an isolated heart model. Guinea-pig heart s were perfused using the Langendorff technique. After 20 min stabilization global ischaemia was induced for 15 min at 37 degrees C. With the onset of reperfusion 10(7) isolated polymorphonuclear leukocytes (PMN), prelabelled with rhodamine 6G, were infused within 1 min. Perfusion was continued for 2 min to wash out all cells not firmly adhering to the vascular endothelium . Hearts were then arrested, mounted on a microscope stage and perfused wit h a cardioplegic solution containing 0.01% fluorescein isothiocyanate (FITC )-dextran (MW 150,000). In situ videofluorescence microscopy was used to qu antify PMN plugging and adherent PMN. Four groups were studied: control (no treatment or ischaemia, n=6); ischaemia trio treatment and 15 min ischaemi a, n=5; fucoidin (pretreatment of hearts and PMN with 0.3 mg/ml selectin in hibitor fucoidin and 15 min ischaemia, n=5) and CD18 (pretreatment of PMN w ith 0.1 mg monoclonal antibody against CD18 and 15 min ischaemia, n=5). Cap illary plugging by PMN was 25+/-5 PMN/mm(2) epicardial surface area and inc reased moderately to 55+/-6 PMN/mm(2) in reperfused hearts. This increase w as not affected by fucoidin or CD18 antibody. In contrast, post-ischaemic a dhesion of PMN in small venules increased ninefold from 21+/-5 to 196+/-23 PMN/mm(2) endothelial surface area. The increase in PMN adhesion to venular endothelium was blocked completely by pretreatment with fucoidin (19+/-5 P MN/mm(-2)) or CD18 antibody (7+/-2 PMN/mm(-2)). We conclude that selectin i nteraction alone is not sufficient to account for post-ischaemic PMN adhesi on in the small venules of the coronary vasculature, because blocking the i ntegrin subunit CD18 also inhibited PMN adhesion completely. On the other h and, neither integrins nor selectins seem to be involved in post-ischaemic capillary plugging by PMN in our perfused heart model.