TY - JOUR
T1 - Resistin impairs endothelium-dependent dilation to bradykinin, but not acetylcholine, in the coronary circulation
AU - Dick, Gregory M.
AU - Katz, Paige S.
AU - Farias, Martin
AU - Morris, Michael
AU - James, Jeremy
AU - Knudson, Jarrod D.
AU - Tune, Johnathan D.
PY - 2006
Y1 - 2006
N2 - Elevated plasma levels of fat-derived signaling molecules are associated with obesity, vascular endothelial dysfunction, and coronary heart disease; however, little is known about their direct coronary vascular effects. Accordingly, we examined mechanisms by which one adipokine, resistin, affects coronary vascular tone and endothelial function. Studies were conducted in anesthetized dogs and isolated coronary artery rings. Resistin did not change coronary blood flow, mean arterial pressure, or heart rate. Resistin had no effect on acetylcholine-induced relaxation of artery rings; however, resistin did impair bradykinin-induced relaxation. Selective impairment was also observed in vivo, as resistin attenuated vasodilation to bradykinin but not to acetylcholine. Resistin had no effect on dihydroethidium fluorescence, an indicator of superoxide (O2-) production, and the inhibitory effect of resistin on bradykinin-induced relaxation persisted in the presence of Tempol, a superoxide dismutase mimetic. To determine whether resistin impaired production of and/or responses to nitric oxide (NO) or prostaglandins (e.g., prostacyclin; PGI2), we performed experiments with Nω-nitro-L-arginine methyl ester (L-NAME) and indomethacin. The effect of resistin to attenuate bradykinin-induced vasodilation persisted in the presence of L-NAME or indomethacin, suggesting resistin may act at a cell signaling point upstream of NO or PGI2 production. Resistin-induced endothelial dysfunction is not generalized, and it is not consistent with effects mediated by O2- or interference with NO or PGI2 signaling. The site of the resistin-induced impairment is unknown but may be at the bradykinin receptor or a closely associated signal transduction machinery proximal to NO synthase or cyclooxygenase.
AB - Elevated plasma levels of fat-derived signaling molecules are associated with obesity, vascular endothelial dysfunction, and coronary heart disease; however, little is known about their direct coronary vascular effects. Accordingly, we examined mechanisms by which one adipokine, resistin, affects coronary vascular tone and endothelial function. Studies were conducted in anesthetized dogs and isolated coronary artery rings. Resistin did not change coronary blood flow, mean arterial pressure, or heart rate. Resistin had no effect on acetylcholine-induced relaxation of artery rings; however, resistin did impair bradykinin-induced relaxation. Selective impairment was also observed in vivo, as resistin attenuated vasodilation to bradykinin but not to acetylcholine. Resistin had no effect on dihydroethidium fluorescence, an indicator of superoxide (O2-) production, and the inhibitory effect of resistin on bradykinin-induced relaxation persisted in the presence of Tempol, a superoxide dismutase mimetic. To determine whether resistin impaired production of and/or responses to nitric oxide (NO) or prostaglandins (e.g., prostacyclin; PGI2), we performed experiments with Nω-nitro-L-arginine methyl ester (L-NAME) and indomethacin. The effect of resistin to attenuate bradykinin-induced vasodilation persisted in the presence of L-NAME or indomethacin, suggesting resistin may act at a cell signaling point upstream of NO or PGI2 production. Resistin-induced endothelial dysfunction is not generalized, and it is not consistent with effects mediated by O2- or interference with NO or PGI2 signaling. The site of the resistin-induced impairment is unknown but may be at the bradykinin receptor or a closely associated signal transduction machinery proximal to NO synthase or cyclooxygenase.
KW - Adipokine
KW - Hormone
KW - Obesity
KW - Reactive oxygen species
UR - http://www.scopus.com/inward/record.url?scp=33845399034&partnerID=8YFLogxK
U2 - 10.1152/ajpheart.01035.2005
DO - 10.1152/ajpheart.01035.2005
M3 - Article
C2 - 16905596
AN - SCOPUS:33845399034
SN - 0363-6135
VL - 291
SP - H2997-H3002
JO - American Journal of Physiology - Heart and Circulatory Physiology
JF - American Journal of Physiology - Heart and Circulatory Physiology
IS - 6
ER -