Effect of cold pressor stimulation on plasma norepinephrine, dopamine-beta-hydroxylase, and renin activity

Changes in plasma levels of norepinephrine, dopamine-β-hydroxylase (DβH), and renin activity were observed in nine healthy volunteers during cold pressor stimulation. Increases in mean arterial blood pressure and heart rate during cold stimulation were accompanied by a sharp rise in plasma norepinephrine, while plasma DβH and renin activity showed little or no change. The results indicate that plasma norepinephrine accurately reflects acute activation of the sympathetic nervous system in contrast to plasma DβH and renin activity.