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MMP9 from Bone Marrow‐Derived Cells Regulates Arteriogenesis and Skeletal Muscle Regeneration in a Hindlimb Ischemia Model
Author(s) -
Meisner Joshua,
Sumer Suna,
Bajikar Sameer S,
Price Richard J
Publication year - 2011
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.25.1_supplement.1092.15
Subject(s) - microcirculation , arteriole , laser doppler velocimetry , biomedical engineering , intravital microscopy , arteriogenesis , blood flow , velocimetry , anatomy , materials science , chemistry , medicine , ischemia , optics , physics
Microvascular blood flow is regulated by vessel‐, tissue‐, and blood‐derived factors that interact with, and feedback on, each other continuously through space and time. Through these factors, a local perturbation (i.e. occlusion of an arcade arteriole) can impact flow throughout an entire network. However, direct measurements of such network‐wide responses are lacking, due, in large part, to methodological difficulty. Here, we developed and validated a laser speckle flowmetry (LSF) method for measuring changes in flow at single arteriole resolution throughout large, intact microvascular networks efficiently and quickly. Dorsal‐skinfold window chambers were implanted on C57BL6 mice for observation of skin microcirculation. During intravital microscopy, a 658 nm wavelength laser illuminated the field of view for LSF using a spatial contrast algorithm. Flow measurements of individual microvessels generated by LSF were validated against those obtained through particle imaging velocimetry (PIV) of circulating fluorescent microspheres. The developed LSF method allowed for imaging vascular networks >80 mm 2 in area and at a resolution of <10 μm/pixel in <10 minutes. Each network contained at least 40 measurable arteriolar and venular segments. Further, LSF measurements exhibited a significant correlation with PIV measurements within (R 2 =0.79±0.03, n=4) and across (R 2 =0.689) specimens with flow rates ranging from 0.07 to 8.1 μl/min. In conclusion, we have demonstrated the feasibility of using LSF for the measurement of microvascular relative flow across large microvascular networks. Future studies will seek to demonstrate the applicability of this technique across other commonly utilized intravital microscopy preparations. Supported by NIH HL74082 and AHA 10GRNT3490001.