Neurohormonale

Neurohormonal signaling refers to chemical signals released by neurosecretory cells into the bloodstream to act on distant targets, thereby linking the nervous and endocrine systems. This mode of communication enables regulatory effects over longer timescales and across wider areas than conventional nerve transmission.

Sources and pathways are diverse. A major example involves hypothalamic neurons that secrete releasing and inhibiting hormones into the hypophyseal portal system to regulate the anterior pituitary. Other neurohormones are produced by neurons and released from the posterior pituitary into the circulation, such as oxytocin and vasopressin. Hormones from other neuroendocrine sites, including the pineal gland (melatonin), also function as neurohormones when their release is controlled by neural input.

Functions controlled by neurohormonal signals include growth and metabolism, osmoregulation, stress responses, reproduction, and circadian rhythms. By acting on distant target organs, neurohormones coordinate complex physiological processes that require integration across tissues and organ systems.

Clinical relevance is notable in several areas. Dysregulation of neurohormonal pathways underlies pituitary disorders and certain neuroendocrine tumors. In cardiovascular medicine, a concept known as neurohormonal activation describes heightened activity of systems such as the sympathetic nervous system and the renin-angiotensin-aldosterone axis, which influence conditions like heart failure and hypertension. Understanding neurohormonal signaling informs diagnostics, therapeutics, and the study of integrative physiology.