Plasma and Cerebrospinal Fluid Beta-Endorphin Levels Show a Strong Association in Children with Cerebral Malaria

Roles of β-Endorphin in Stress, Behavior, Neuroinflammation, and Brain Energy Metabolism

β-Endorphins are peptides that exert a wide variety of effects throughout the body. Produced through the cleavage pro-opiomelanocortin (POMC), β-endorphins are the primarily agonist of mu opioid receptors, which can be found throughout the body, brain, and cells of the immune system that regulate a diverse set of systems. As an agonist of the body's opioid receptors, β-endorphins are most noted for their potent analgesic effects, but they also have their involvement in reward-centric and homeostasis-restoring behaviors, among other effects. These effects have implicated the peptide in psychiatric and neurodegenerative disorders, making it a research target of interest. This review briefly summarizes the basics of endorphin function, goes over the behaviors and regulatory pathways it governs, and examines the variability of β-endorphin levels observed between normal and disease/disorder affected individuals.

Serum β-endorphin levels are associated with addiction to suicidal behavior: A pilot study

The literature provides partial support for the hypothesis that some suicide attempters develop a behavioral addiction to suicidal behavior (SB). We hypothesized that major suicide repeaters (MR) (≥5 lifetime suicide attempts) are addicted to suicide attempts as measured by modified DSM-IV criteria for substance dependence. In this cross-sectional study with 13 psychiatric controls (PC), 55 non-major suicide attempters (NMR), and 9 MR we found that MR are characterized by emotional abuse and neglect, as well as higher scores on the Personality and Life Event scale (short version). The levels of 8 AM serum ACTH, cortisol and β-endorphin were elevated in all three groups. Serum β-endorphin (pg/mL) was particularly high in PC diagnosed with schizophrenia 220.34 (±56.30). The level of 8 AM serum β-endorphin rose with increased numbers of criteria met for addiction to SB from 130.31 (±88.16) (≥ 3 criteria met for addiction to SB) to 174.84 (±114.93) (≥ 6 criteria met for addiction to SB) whereas serum ACTH and cortisol did not change. SB addicts (≥ 6 criteria) displayed higher serum β-endorphin concentrations than non-addicts (174.84 ± 114.93 vs. 116.93 ± 61.70, FET p = 0.09). The present study brings some support to the addictive hypothesis of SB. Our results delineate β-endorphin as a promising biomarker of SB addiction, and offer a good basis for future studies that test whether buprenorphine can be used to prevent repetitive suicide attempts, non-suicidal-self-injury (NSSI), and the development of an addiction to SB.

Endogenous Opiates and Behavior: 2018

This paper is the forty-first consecutive installment of the annual anthological review of research concerning the endogenous opioid system, summarizing articles published during 2018 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides and receptors as well as effects of opioid/opiate agonists and antagonists. The review is subdivided into the following specific topics: molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors (2), the roles of these opioid peptides and receptors in pain and analgesia in animals (3) and humans (4), opioid-sensitive and opioid-insensitive effects of nonopioid analgesics (5), opioid peptide and receptor involvement in tolerance and dependence (6), stress and social status (7), learning and memory (8), eating and drinking (9), drug abuse and alcohol (10), sexual activity and hormones, pregnancy, development and endocrinology (11), mental illness and mood (12), seizures and neurologic disorders (13), electrical-related activity and neurophysiology (14), general activity and locomotion (15), gastrointestinal, renal and hepatic functions (16), cardiovascular responses (17), respiration and thermoregulation (18), and immunological responses (19).