Increased basal and reactive plasma norepinephrine and epinephrine levels in awake DOCA-salt hypertensive rats.

The sympatho-adrenal basal tone and reactivity were studied using plasma norepinephrine (NE) and epinephrine (E) levels in awake DOCA-salt hypertensive rats. In those animals, basal NE and E levels were about twice greater than those found in normotensive rats. Moreover, plasma NE levels could be significantly correlated with mean arterial pressures in both groups of animals. Following a hemorrhagic hypotension, elevation in NE and E levels tended to be greater in hypertensive rats. These studies suggest that the basal activity of the sympatho-adrenal system is increased and that its reactivity might be potentiated in DOCA-salt hypertension.