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A Fibronectin Fragment Elicits Vasodilatation and Alters Myogenic Responsiveness of Skeletal Muscle Arterioles
Author(s) -
Chao JT. Sherry,
Davis George E,
Davis Michael J
Publication year - 2010
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.24.1_supplement.600.4
Subject(s) - fibronectin , vasodilation , myogenic contraction , integrin , skeletal muscle , chemistry , endocrinology , vascular smooth muscle , medicine , extracellular matrix , anatomy , biochemistry , receptor , smooth muscle
Interactions between integrin‐extracellular matrix proteins are important modulators of vascular tone that are altered during vascular remodeling, wound healing, and inflammation. Degraded collagen, which contains integrin‐binding sequences Arg‐Gly‐Asp (RGD), has been shown to modulate vascular tone by altering calcium entry. In this study, we investigated the effects of a proteolytic fragment of fibronectin (FN120) on vascular tone in isolated, cannulated, and pressurized rat skeletal muscle arterioles. Abluminal incubation with FN120 (1, 10, 100 μM) for 15 minutes elicited a dose‐dependent, transient dilatation at 90 cmH 2 O intraluminal pressure, with 10 μM FN120 producing significant dilation (n=9, p=0.03). FN120 (10 μM) also significantly increased the steady‐state myogenic index (−0.3; control: −0.13; n=9, p=0.02), as measured over the pressure range of 60–180 cmH 2 O. After wash‐off and re‐application of FN120, the time to peak transient dilation at 60 cmH 2 O was markedly shortened (from 8 to 1.5 minutes for 10 μM FN120), compared to the first application. To determine if these effects depended on FN‐integrin interactions, arterioles were pre‐incubated with a β 1 integrin function blocking antibody (26 μg/mL) prior to addition of 10 μM FN120. The β 1 integrin antibody blunted the steady‐state dilation to FN120 (25% decrease; p=0.039) and attenuated the increased myogenic index (−0.3 to −0.1; n=3, p=0.03). Our data suggest that the interaction between this FN fragment and β 1 integrin may be important components of vascular remodeling. Supported by NIH 072989 to MJD.