Recurrent autonomic dysreflexia exacerbates vascular dysfunction after spinal cord injury
Nima Alan1, Leanne M Ramer, Jessica A Inskip
1International Collaboration on Repair Discoveries (ICORD), University of British Columbia, Blusson Spinal Cord Centre, Vancouver, British Columbia, Canada.
The Spine Journal : Official Journal of the North American Spine Society
|November 25, 2010
Summary
Repeated autonomic dysreflexia (AD) after spinal cord injury (SCI) can alter blood vessel function. This study shows that AD episodes significantly impact vascular responses, suggesting a need for stable blood pressure management in SCI patients.
Area of Science:
- Neuroscience
- Cardiovascular Research
- Physiology
Background:
- Individuals with high spinal cord injury (SCI) experience blood pressure fluctuations, including autonomic dysreflexia (AD) and orthostatic hypotension.
- The impact of this blood pressure variability on the vasculature remains largely unknown.
Purpose of the Study:
- To investigate whether increased frequency of AD exacerbates injury-induced vascular dysfunction in a rodent model.
- To determine the long-term effects of AD on resistance vessel function following SCI.
Main Methods:
- A T3 spinal cord transection model was used in male Wistar rats.
- Autonomic dysreflexia was induced daily for 14 days post-injury using colorectal distension (CRD).
- Mesenteric arteries were analyzed using in vitro myography to assess responses to phenylephrine and acetylcholine.
Main Results:
- Mesenteric arteries from SCI rats with induced AD showed enhanced responses to phenylephrine compared to SCI-only controls.
- Endothelial function was preserved, as indicated by similar acetylcholine-induced vasodilation in both groups.
- While both groups exhibited CRD-induced AD, prior AD exposure attenuated the hypertensive response.
Conclusions:
- Spinal cord injury induces vascular changes that may contribute to AD development.
- Autonomic dysreflexia itself has lasting detrimental effects on vascular function.
- Findings underscore the importance of managing blood pressure stability in SCI patients.
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