Premium
Differences between leukocyte‐EC interactions in arterioles vs. venules may be related to ICAM‐1.
Author(s) -
Sumagin Ronen,
Sarelius Ingrid H
Publication year - 2006
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.20.4.a648
Subject(s) - venule , microcirculation , intravital microscopy , inflammation , intercellular adhesion molecule 1 , cremaster muscle , icam 1 , chemistry , cell adhesion molecule , pathology , arteriole , immunology , microbiology and biotechnology , biology , medicine
The observation that an inflammatory stimulus upregulates adhesion molecule expression in arterioles suggests an explicit role for arterioles in inflammation. We used intravital confocal microscopy to study the connection between ICAM‐1 expression levels and leukocyte‐EC interactions in cremaster muscle arterioles and venules of anesthetized mice (Nembutal, 74 mg/ml). To compare normal and inflammatory conditions we used control and TNF‐α (500ng, intrascrotally) treated mice. We observed ICAM‐1 dependent rolling in arterioles and ICAM‐1 dependent adhesion in venules. Interestingly, ICAM‐1 expression levels increased 2‐3 fold following TNF‐α treatment in both arterioles and venules, but leukocyte adhesion events were rarely found in arterioles compared to venules (0.6 vs 5.5/100μm). Note that the potential for an adhesion event was similar in both arterioles and venules since the delivered flux of leukocytes to the vessel wall was the same (10 leukocyte/40 sec). On the other hand, the number of rolling leukocytes was significantly higher at the regions of higher ICAM‐1 density (r 2 =0.56) in arterioles but not in venules (r 2 =0.11). We also found that the number of firmly adhered leukocytes in venules linearly increased with ICAM‐1 expression levels (r 2 =0.59). Although an inflammatory stimulus did not induce leukocyte adhesion in arterioles as it did in venules, elevated ICAM‐1 levels were found to correlate with the increased number of rolling leukocytes in arterioles, suggesting that ICAM‐1 and arterioles play an important role in inflammation. (Supported by NIH HL18208 and HL75186)