Heat shock augments angiotensin II-induced vascular contraction through increased production of reactive oxygen species.
A temporal increase in temperature triggers a series of stress responses and alters vascular smooth muscle (VSM) contraction induced by agonist stimulation. Here we examined the role of reactive oxygen species (ROS) in heat shock-dependent augmentation of angiotensin II (AngII)-induced VSM contraction. Endothelium-denuded rat aortic rings were treated with heat shock for 45 min at 42 degrees C and then subjected to assays for the production of force, ROS, and the expression of ROS-related enzymes. AngII-induced contraction was enhanced in heat shock-treated aorta. AngII-induced production of hydrogen peroxide and superoxide were elevated in response to the heat shock treatment. Pre-treatment with superoxide dismutases (SOD) mimetic and inhibitors for glutathione peroxidase and NADPH oxidase but not for xanthine oxidase eliminated an increase in the AngII-induced contraction in the heat shock-treated aorta. Heat shock increased the expression of p47phox, a cytosolic subunit of NADPH oxidase, but not Cu-Zn-SOD and Mn-SOD. In addition, heat shock increased contraction that was evoked by hydrogen peroxide and pyrogallol. These results suggest that heat shock causes an elevation of ROS as well as a sensitization of ROS signal resulting in an augmentation of VSM contraction in response to agonist.
Kim
Jee In
JI
Department of Pharmacology and Cardiovascular Research Institute, Kyungpook National University School of Medicine, Daegu 700-422, Republic of Korea.
Jung
Sang Won
SW
Yang
Enyue
E
Park
Kwon Moo
KM
Eto
Masumi
M
Kim
In Kyeom
IK
D000804:Angiotensin II / Q000494:pharmacology; D000818:Animals; D001011:Aorta / Q000187:drug effects / Q000502:physiology; D018869:Heat-Shock Response; D009131:Muscle, Smooth, Vascular / Q000187:drug effects / Q000502:physiology*; D009249:NADP / Q000096:biosynthesis; D019255:NADPH Oxidases / Q000096:biosynthesis; D051381:Rats; D017382:Reactive Oxygen Species / Q000378:metabolism*; D013482:Superoxide Dismutase / Q000096:biosynthesis; D014661:Vasoconstriction
D017382:Reactive Oxygen Species; D000804:Angiotensin II; D009249:NADP; D013482:Superoxide Dismutase; D019255:NADPH Oxidases; C060505:neutrophil cytosolic factor 1