Pharmacologic treatment of autonomic dysreflexia in the rat.
Autonomic dysreflexic hypertension occurs in up to 80% of spinal cord injury patients with lesions thoracic level 6 or higher. Pharmacologic agents directed at each part of the autonomic dysreflexic circuit were tested for efficacy in a rat model. Guanethidine (15 mg/kg intraperitoneally), alpha-methyl-paratyrosine (20 mg/kg intraperitonally), propranolol (3 mg/kg intraperitonally) and control were each tested on groups of three rats with intrinsic control blood pressure measurements. Results show an increase of 15 +/- 5 mm Hg diastolic pressure in control animals compared with no detectable increase with guanethidine or alpha-methyl-paratyrosine. There was an 11 +/- 2 mm Hg increase in diastolic pressure with propranolol. In conclusion, screening drug trials show that the ganglionic blocking agent, guanethidine, and competitive tyrosine uptake precursor, alpha-methyl-paratyrosine, effectively blocked dysreflexic hypertension, whereas the beta-blocker, propranolol, did not.
Chiou-Tan
F Y
FY
Department of Physical Medicine and Rehabilitation, Baylor College of Medicine, Houston, Texas 77030.
Lenz
M L
ML
Robertson
C S
CS
Grabois
M
M
D000818:Animals; D000959:Antihypertensive Agents / Q000627:therapeutic use*; D001342:Autonomic Nervous System Diseases / Q000503:physiopathology*; D004353:Drug Evaluation, Preclinical; D006145:Guanethidine / Q000627:therapeutic use; D006973:Hypertension / Q000188:drug therapy* / Q000503:physiopathology; D008297:Male; D008781:Methyltyrosines / Q000627:therapeutic use; D011433:Propranolol / Q000627:therapeutic use; D051381:Rats; D017207:Rats, Sprague-Dawley; D012021:Reflex, Abnormal / Q000187:drug effects; D014446:Tyrosine 3-Monooxygenase / Q000037:antagonists & inhibitors; D019805:alpha-Methyltyrosine
D000959:Antihypertensive Agents; D008781:Methyltyrosines; D019805:alpha-Methyltyrosine; D011433:Propranolol; D014446:Tyrosine 3-Monooxygenase; D006145:Guanethidine