Endorfine

Endorphins are endogenous opioid neuropeptides that act as neurotransmitters and neuromodulators in the mammalian nervous system. They are produced primarily in the pituitary gland and certain brain regions, and they play roles in pain perception, stress response, and reward. The term "endorphin" is standard in English; in German, the plural is "Endorphine," and some sources may render related forms such as "Endorfine" as variants. Endorphins belong to a family that includes beta-endorphin, enkephalins, and dynorphins, each derived from larger precursor proteins.

Biochemically, beta-endorphin is derived from the precursor molecule proopiomelanocortin (POMC); enkephalins come from proenkephalin; dynorphins from prodynorphin. Endorphins exert their primary effects by binding to mu-opioid receptors, though interactions with delta- and kappa-receptors also contribute. This receptor binding reduces excitability of pain pathways, producing analgesia and, in some contexts, euphoria and a sense of well-being.

Release of endorphins is triggered by stress, pain, intense exercise, and certain stimuli such as acupuncture or laughter. They modulate pain signals in the spinal cord and brain and influence mood, appetite, and the immune system. Endorphins interact with the endogenous opioid system and can interact with exogenous opioid medications, affecting analgesic efficacy and tolerance.

Research into endorphins continues to explore their precise roles in pain control, mood disorders, and addiction. Measuring circulating endorphin levels is challenging due to rapid degradation and localized production; cerebrospinal fluid levels better reflect central activity but are harder to obtain. The safety profile is tied to the broader opioid system, with potential risks including respiratory depression and dependence when interacting with opioid drugs.