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Role of endothelial surface layer in mediation of flow‐induced dilation of isolated arterioles
Author(s) -
Marki Alex,
Gara Edit,
Veresh Zoltan,
Seress Laszlo,
Toth Peter,
Koller Akos
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.975.15
Subject(s) - hyaluronidase , acetylcholine , intracellular , chemistry , vasomotor , endocrinology , biophysics , medicine , anatomy , biology , enzyme , biochemistry
Vascular endothelial cells respond to increases in wall shear stress (WSS) by releasing vasoactive factors. However, it is less known how WSS signal is sensed by the endothelial cells. Recent studies implied that the endothelial surface layer (ESL) senses changes in WSS and transmits the signal towards intracellular enzymes responsible for producing these factors. We hypothesized that degradation of ESL inhibits flow‐induced dilation of arterioles. Thus the effect of step‐wise increases in intraluminal flow were investigated on the diameter of isolated gracilis muscle arterioles of rats (passive diameter ~200μm, active diameter ~150μm) in the absence and presence of intraluminal hyaluronidase (1.5 and 15 U/ml, for 30 minutes) known to degrade hyaluronic acid of the ESL. In control conditions acetylcholine (ACh) and flow elicited dilations (20±6% and 20±2%, respectively). Presence of 1.5 U/ml hyaluronidase reduced ACh‐induced dilations, but did not affect flow‐induced responses. In contrast, 15 U/ml hyaluronidase elicited significant reduction of both Ach‐ and flow‐induced dilations (to 7±2% and to 2±1%), whereas vasomotor responses of smooth muscle remain intact. These results provide further support for the potential role of the ESL in sensing and transmitting changes in WSS. (Grants: Hungarian Nat. Sci. Res. Fund.‐OTKA K71591, K67984, AHA Founders Aff., 0855910D)