Plasma Catecholamines during Paroxysmal

SUMMARY Blood pressure, heart rate, and plasma catecbol-araiDe levels were measured in 16 <piadripiegic objects with physio-logically complete cerrical spinal cord traawctkms above tbe level of the sympathetic outflow, and in IS normal subjects (controls). In the quadriplegics the average resting Uood pressure was 107/59 (mean, 75) mm Hg, heart rate was 65 beats/min, and plasma norepinephrine (NE) and epinephrine (E) levels were 0.05 and 0.005 ng/ml, respectively. In the controls average resting Uood pressure was 117/79 (mean, 92) mm Hg, heart rate was 61 beats/mia, and resting plasma NE and E levels were 0.20 and 0.06 ng/ral, respectively. Resting Uood pressure and plasma NE and E levels were significantly lower in the quadriplegics (P <0.01, <0.001, <0.001, and <0.001, < 0.001, respectively) than in tbe controls. In tbe quadriplegics, nenrogenic hypertension was induced by Madder and nrasde stimula-tion. This resulted in a marked elevatioa of both systolic and diastoli