Vessel-specific rate of vasorelaxation is slower in diabetic rats. (March 2013)

• Record Type: Journal Article
• Authors: Murias, Juan M; Campos, Oscar A; Hall, Katharine E; McDonald, Matthew W; Melling, CW James; Noble, Earl G
• Is Part Of: Diabetes & vascular disease research. Volume 10:Number 2(2013)
• Page Start: 179
• Page End: 186
• Publication Date: 2013-03
• Subjects: Endothelium-dependent vasorelaxation -- vessel myography -- vascular responsiveness -- vascular kinetics -- type 1 diabetes; Diabetic angiopathies -- Periodicals; 616.462005
• DOI: 10.1177/1479164112454758
• Languages: English
• ISSNs: 1479-1641

Abstract

The rate of adjustment of endothelium-dependent vasorelaxation was examined in the aorta, iliac and femoral arteries of eight control and eight diabetic rats with and without supplementation with vitamin C. Vessels were constricted using 10 −5 M phenylephrine (PE) and relaxed with 10 −4 M acetylcholine (ACh condition) or 10 −4 M ACh plus 10 −4 M vitamin C (ACh + vitamin C condition) in a myography system. Vasorelaxation was modelled as a mono-exponential function using a non-linear regression analysis. The adjustment (τ) of vasorelaxation was faster in control (6.6 ± 3.2 s) compared to diabetic rats (8.4 ± 3.4 s) ( p < 0.05). The time-to-steady-state tended to be shorter in control (32.0 ± 13.9 s) compared to diabetic rats (38.0 ± 15.0 s) ( p = 0.1). ACh + vitamin C did not speed the vasorelaxation response. The τ for vasorelaxation was shorter in the femoral (6.5 ± 2.7 s) and iliac (6.8 ± 2.5 s) compared to the aorta (9.2 ± 4.2 s) ( p < 0.05). The rate of vasorelaxation was greater in the femoral (3.2 ± 1.4%·s −1 ) compared to the iliac (2.0 ± 1.0%·s −1 ) and aorta (1.1 ± 0.4%·s −1 ) in both groups and in the iliac compared to the aorta ( p < 0.05) in the control group. In conclusion, the vasorelaxation response was vessel specific with a slower rate of adjustment in diabetic compared to control animals.