Norepinephrine, Plasma Unit Converter

Norepinephrine (also called noradrenaline) is a catecholamine that acts as both a neurotransmitter and a hormone. It plays a central role in your body's "fight-or-flight" response, helping regulate blood pressure, heart rate, and alertness.

Plasma norepinephrine measures the amount of free norepinephrine circulating in your blood. It is typically ordered alongside other catecholamines (epinephrine and dopamine) as part of a fractionated plasma catecholamine panel.

Norepinephrine is the most abundant catecholamine in the sympathetic nervous system, and the majority of circulating norepinephrine comes from nerve endings rather than the adrenal glands.

Most plasma norepinephrine is released from sympathetic nerve endings throughout the body. A smaller amount is secreted by the adrenal medulla, where it is synthesized from dopamine by the enzyme dopamine beta-hydroxylase.