beta-endorphin and Heart-Arrest

To investigate the possible participation of endogenous opioids in the cerebral events that take place at the moment of death we studied brain, cerebrospinal fluid and serum contents of beta-endorphin in dogs that were either conscious or unconscious at the moment of sudden death induced by cardiac arrest. Although with great interindividual variations, the animals that were conscious at the moment of cardiac arrest, presented a significant increase in beta-endorphin when compared with their own previous values (p < 0.05) or with the values found in animals that were deeply anaesthetized at the time of cardiac arrest. There seems to be a sudden increment of beta-endorphin in brain tissue and body fluids of dogs who are conscious at the moment of sudden death, this change was not observed in dogs that were anaesthetized prior to death. Brain opioids could participate in the sensations narrated by subjects in the so called near-death experience.

Topics: Animals; beta-Endorphin; Brain; Brain Chemistry; Death, Sudden, Cardiac; Dogs; Heart Arrest

The levels of gamma 3-MSH immunoreactivity (gamma 3MSH-IR), beta-endorphin immunoreactivity (beta-endorphin-IR), ACTH, PRL, and cortisol were determined in 23 patients with cardiac arrest (CA) and in a group of 22 patients consecutively admitted to the Intensive Care Unit (ICU controls). Blood was obtained immediately after CA and at frequent intervals for the next 2 h. In ICU patients, blood was obtained the morning after admission. gamma 3MSH-IR was consistently elevated after CA; it was present in all 23 patients and was detectable in 113 of 114 samples. The mean peak gamma 3MSH-IR level was 162 +/- 20 (+/- SE) pg/ml in CA patients and the mean gamma 3MSH-IR level was 35 +/- 6 pg/ml in ICU controls (P less than 0.01). gamma 3MSH-IR was undetectable (less than 20 pg/ml) in normal subjects. CA also was associated with increases in ACTH, beta-endorphin-IR, cortisol, and PRL. The group of ICU controls had stress hormone levels that were generally within the normal range. Distribution of plasma beta-endorphin-IR by gel chromatography showed two peaks of immunoreactivity corresponding to the beta-endorphin and beta-lipotropin standards in both the CA and ICU control groups. Distribution of gamma 3MSH-IR in CA plasma showed a major peak of immunoreactivity with a mol wt of approximately 6,000 daltons and two minor components of approximately 4,000 and 11,000 dalton. No immunoreactivity coeluted with a gamma 3MSH standard. We conclude that gamma 3MSH-immunoreactive peptides are a consistent component of the massive release of pituitary and adrenal glandular products after CA.

Topics: Adrenocorticotropic Hormone; beta-Endorphin; Carrier Proteins; Endorphins; Female; Heart Arrest; Humans; Hydrocortisone; Male; Melanocyte-Stimulating Hormones; Middle Aged; Prolactin; Radioimmunoassay