Abstract
Endothelial cell hyperpolarization and EDHF: Local and regional influence of diabetes
Journal of Vascular Research, Vol.49(Supplement 2), p.47
EDHF 10th Anniversary Meeting, 2012 (Vaux-de-Cernay, France, 27-Jun-2012–30-Jun-2012)
2012
Abstract
Endothelial dysfunction is a major risk factor for the vascular complications of diabetes. Endothelium-derived hyperpolarizing factor (EDHF) is an important vasodilator mechanism in small arteries and arterioles and its actions are impaired in diabetes. Endothelial cell hyperpolarization is the initial step involved in the genesis of EDHF vasodilator activity. We investigated the mechanisms influencing EDHF function in mesenteric and hindlimb beds of rats with type I diabetes. Diabetes was induced in male Wistar rats with streptozotocin (60mg/kg) incitrate buffer and controls received buffer alone. Eight weeks after injection EDHF function was examined. In mesenteric arteries endothelial cell hyperpolarization and EDHF-mediated smoothmuscle hyperpolarization and relaxation were halved in diabetes. The contributions of both intermediate (IKCa) and small (SKCa)-conductance calcium activated potassium channels were reduced, with protein expression of the channels unaltered. The functional patency of myoendothelial gap junctions (MEGJs) was preserved. The role of calcium stores and TRPC3 in the generation of mesenteric endothelial cell hyperpolarization and the influence of diabetes was also examined. Local superoxide generation was upregulated in diabetic mesenteric arteries. In small femoral arteries where endothelial cells do not form MEGJs with smooth muscle cells, endothelialcell hyperpolarization was preserved, KCa channel protein expression was unchanged or increased. Local superoxide generation was unaltered in this region. In conclusion, diabetes has regional and differential effects on endothelial function. Impairment of mesenteric EDHF relaxation is due to impairment in the generation of endothelial cell hyperpolarization and not in the functional disruption of the MEGJ pathway.
Details
- Title
- Endothelial cell hyperpolarization and EDHF: Local and regional influence of diabetes
- Authors
- M Tare (Author) - Monash UniversityS Senadheera (Author) - University of New South WalesShaun L Sandow (Author) - University of New South WalesH A Coleman (Author) - Monash UniversityH C Parkington (Author) - Monash University
- Publication details
- Journal of Vascular Research, Vol.49(Supplement 2), p.47
- Conference details
- EDHF 10th Anniversary Meeting, 2012 (Vaux-de-Cernay, France, 27-Jun-2012–30-Jun-2012)
- Publisher
- S. Karger AG
- Date published
- 2012
- DOI
- 10.1159/000339218
- ISSN
- 1018-1172
- Organisation Unit
- School of Health - Biomedicine; University of the Sunshine Coast, Queensland; School of Health and Sport Sciences - Legacy; School of Health and Behavioural Sciences - Legacy
- Language
- English
- Record Identifier
- 99449003702621
- Output Type
- Abstract
Metrics
4 File views/ downloads
624 Record Views