Long-term ouabain treatment impairs vascular function in resistance arteries.
J Vasc Res
; 48(4): 316-26, 2011.
Article
in En
| MEDLINE
| ID: mdl-21273786
ABSTRACT
BACKGROUND/AIMS:
The purpose of this study was to examine the cardiovascular effects of long-term ouabain treatment at different time points.METHODS:
Systolic blood pressure (SBP) was measured by tail-cuff method in male Wistar rats treated with ouabain (approx. 8.0 µg·day(-1)) or vehicle for 5, 10 and 20 weeks. Afterwards, vascular function was assessed in mesenteric resistance arteries (MRA) using a wire myograph. ROS production and COX-1 and COX-2, TNF-α, and IL-6 protein expression were investigated.RESULTS:
SBP was increased by ouabain treatment up to the 6th week and remained stable until the 20th week. However, noradrenaline-induced contraction increased only in MRA in rats treated with ouabain for 20 weeks. NOS inhibition and endothelium removal increased the noradrenaline response, but to a smaller magnitude in MRA in the ouabain group. Moreover, inhibition of COX-2 or incubation with superoxide dismutase restores noradrenaline-induced contraction in the 20-week ouabain group to control levels. ROS production as well as COX-2, IL-6 and TNF-α protein expression increased in MRA in this group.CONCLUSION:
Although ouabain treatment induced hypertension in all groups, a larger noradrenaline induced contraction was observed over 20 weeks of treatment. This vascular dysfunction was related to COX-2-derived prostanoids and oxidative stress, increased pro- inflammatory cytokines and reduced NO bioavailability.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Ouabain
/
Mesenteric Arteries
Limits:
Animals
Language:
En
Journal:
J Vasc Res
Journal subject:
ANGIOLOGIA
Year:
2011
Type:
Article
Affiliation country:
Brazil