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Systemic hypertension alters vasomotor function in experimental vein grafts
M K O'Donohoe1, Z S Radic, L B Schwartz
1Department of Surgery, Duke University Medical Center, Durham, NC 27710.
Journal of Vascular Surgery
|July 1, 1991
Summary
Hypertension in rabbits negatively impacts vein graft function and structure. Hypertensive vein grafts show increased sensitivity to vasoactive agents and impaired relaxation, potentially reducing graft patency.
Area of Science:
- Vascular Surgery
- Cardiovascular Research
- Hypertension Research
Background:
- Hypertension is a known risk factor for atherosclerosis and vein graft failure.
- Hypertension can negatively affect arterial vasoreactivity.
- Understanding the impact of hypertension on vein graft characteristics is crucial for improving graft patency.
Purpose of the Study:
- To assess the vasomotor function and histologic characteristics of autogenous vein grafts in hypertensive rabbits.
- To compare vein grafts from hypertensive rabbits with those from normotensive controls.
Main Methods:
- Hypertension was induced in rabbits using the Goldblatt one clip two kidney method.
- Autogenous external jugular vein grafts were used to bypass the carotid artery.
- Graft responses to vasoactive agents and endothelium-dependent relaxation were evaluated in vitro.
Main Results:
- Hypertensive rabbits exhibited increased intimal hyperplasia, adventitial/medial fibrosis, and reduced vasa vasora in vein grafts.
- Vein grafts from hypertensive rabbits showed hypersensitivity to norepinephrine, histamine, serotonin, and angiotensin II.
- Endothelium-dependent relaxation to acetylcholine and A23187 was impaired or absent in hypertensive vein grafts.
Conclusions:
- Angiotensin-induced hypertension adversely affects vein graft histology and vasomotor function.
- Hypertension leads to hypersensitivity to agonists and reduced relaxation in vein grafts.
- These changes likely contribute to reduced vein graft patency in hypertensive individuals.