What is the Origin of Catecholamine Surge?

The term combines 'catecholamine' (referring to the chemical structure of these monoamine neurotransmitters and hormones) with 'surge' (a sudden, powerful forward or upward movement). This concept is fundamental to understanding the physiology of the sympathetic nervous system and the HPA axis. It describes the body's ancient, conserved neuroendocrine response to perceived acute threats or intense psychological stress.

What is the Mechanism of Catecholamine Surge?

Upon activation of the sympathetic nervous system, preganglionic neurons stimulate the chromaffin cells of the adrenal medulla to rapidly synthesize and release catecholamines directly into the bloodstream. These hormones then bind to adrenergic receptors (alpha and beta) on target tissues throughout the body, triggering a cascade of metabolic and cardiovascular effects. The resulting glycogenolysis and lipolysis provide immediate energy, while vasoconstriction redirects blood flow to vital organs and skeletal muscles.

Catecholamine Surge

Meaning

A rapid, significant, and transient elevation in the circulating concentration of catecholamines, primarily epinephrine (adrenaline), norepinephrine (noradrenaline), and dopamine, released from the adrenal medulla and sympathetic nerve endings. This physiological event is the core hormonal component of the acute “fight-or-flight” stress response, preparing the body for immediate, intense physical or mental exertion. Clinically, it results in increased heart rate, blood pressure, and heightened vigilance.