Related Experiment Videos
Does postsynaptic alpha 1-adrenergic receptor supersensitivity contribute to autonomic dysreflexia?
L M Landrum1, G M Thompson, R W Blair
1Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City 73190, USA.
The American Journal of Physiology
|May 12, 1998
Summary
Autonomic dysreflexia in quadriplegics is not fully explained by alpha 1-receptor supersensitivity. Wistar rats, unlike Sprague-Dawley rats, provide a suitable model for studying this condition.
Area of Science:
- Neuroscience
- Physiology
- Pharmacology
Background:
- Autonomic dysreflexia (AD) is a dangerous hypertensive condition in quadriplegics.
- The precise mechanisms underlying AD remain poorly understood.
- Alpha 1-adrenergic receptor function is a potential factor in exaggerated sympathetic responses.
Purpose of the Study:
- To investigate if postsynaptic alpha 1-adrenergic receptor supersensitivity contributes to autonomic dysreflexia.
- To establish a reliable animal model for studying autonomic dysreflexia.
Main Methods:
- Spinal transection at T5 was performed on adult male Wistar and Sprague-Dawley rats.
- Autonomic dysreflexia was evoked using colorectal distension (CRD) in conscious, spinalized rats.
- Mean arterial pressure (MAP) responses to phenylephrine (PE) infusions were measured to assess alpha 1-receptor sensitivity.
Main Results:
- No significant differences in alpha 1-receptor sensitivity were observed between intact and spinalized rats.
- Alpha 1-receptor supersensitivity does not fully explain the hypertensive episodes in autonomic dysreflexia.
- Spinalized Wistar rats, but not Sprague-Dawley rats, exhibited characteristic MAP responses to CRD, indicating suitability as an AD model.
Conclusions:
- Postsynaptic alpha 1-adrenergic receptor supersensitivity is not the sole mechanism behind autonomic dysreflexia.
- Wistar rats represent a more appropriate animal model for autonomic dysreflexia research compared to Sprague-Dawley rats.