Autonomic dysreflexia increases plasma adrenaline level in the chronic spinal cord-injured rat.

Autonomic dysreflexia (AD) occurs in up to 80% of quadriplegics and high paraplegics and is characterized by exaggerated sympathetic reflexes which induced paroxysmal hypertension. The aim of this study was to determine if plasma catecholamine levels increased during autonomic dysreflexia in the chronic spinal cord-injured (SCI) rats with special care to adrenaline. Catecholamine samples were collected before, during and 1 h after AD induced hypertension with colorectal distension. Results showed that plasma noradrenaline and adrenaline levels increased respectively 1.5-fold and 5-fold during AD in the chronic SCI rats. This suggests substantial roles for these two hormones in mediating the cardiovascular changes during AD. Knowledge of catecholamine levels during AD may thus aid in determining pathophysiology and potential pharmacologic treatments of this autonomic dysfunction.