Plasma norepinephrine concentration reflects pharmacological alteration of sympathetic activity in the conscious cat.

This study provides the first comprehensive set of basal values for hemodynamic variables, plasma norepinephrine (NE) and epinephrine concentrations and plasma renin activity in the conscious cat and demonstrates that changes in plasma NE concentration in the conscious cat accurately reflect the alterations in sympathetic discharge caused by hydralazine, yohimbine, chlorisondamine and clonidine.