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Endogenous Adipose‐Derived Factors Diminish Coronary Endothelial Function via Inhibition of Nitric Oxide Synthase
Author(s) -
Payne Gregory A.,
Borbouse Léna,
Bratz Ian N.,
Roell William C.,
Bohlen H. Glenn,
Dick Gregory M.,
Tune Johnathan D.
Publication year - 2008
Publication title -
microcirculation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.793
H-Index - 83
eISSN - 1549-8719
pISSN - 1073-9688
DOI - 10.1080/10739680701858447
Subject(s) - adipose tissue , bradykinin , medicine , endocrinology , vasodilation , sodium nitroprusside , adipokine , nitric oxide , chemistry , nitric oxide synthase , endothelial dysfunction , receptor , obesity , leptin
ABSTRACT Adipocytokines may be the molecular link between obesity and vascular disease. However, the effects of these factors on coronary vascular function have not been discerned. Accordingly, the goal of this investigation was to delineate the mechanisms by which endogenous adipose‐derived factors affect coronary vascular endothelial function. Both isolated canine coronary arteries and coronary blood flow in anesthetized dogs were studied with and without exposure to adipose tissue. Infusion of adipose‐conditioned buffer directly into the coronary circulation did not change baseline hemodynamics; however, endothelial‐dependent vasodilation to bradykinin was impaired both in vitro and in vivo. Coronary vasodilation to sodium nitroprusside was unaltered by adipose tissue. Oxygen radical formation did not cause the impairment because quantified dihydroethidium staining was decreased by adipose tissue and neither a superoxide dismutase mimetic nor catalase improved endothelial function. Inhibition of nitric oxide (NO) synthase with L‐NAME diminished bradykinin‐mediated relaxations and eliminated the subsequent vascular effects of adipose tissue. In vitro measurement of NO demonstrated that adipose tissue exposure quickly lowered baseline NO and abolished bradykinin‐induced NO production. The results indicate that adipose tissue releases factor(s) that selectively impair endothelial‐dependent dilation via inhibition of NO synthase‐mediated NO production.