Thyrotropin-releasing hormone decreases plasma beta-endorphin level in traumatic tetraplegics--a possible therapeutic agent.

Beta-endorphin and ACTH are concomitantly secreted by the pituitary in response to acute stress and both possess identical regulatory mechanisms (1). Intravenous administration of opioid antagonist naloxone (10 mg) decreased plasma ACTH levels in schizophrenic patients (2). Opioid agonist. morphine (50 mg/kg). administered intraperitoneally elevated plasma beta-endorphin immunoreactivity (3). Spinal cord injury is associated with an increase in the plasma beta-endorphin level Hem a mean value of 6 pgm/ml to 71 pgm/ml (4). Thyrotropin-releasing hormone (TRH) is a tripeptide which does not bind to opiate receptors yet it antagonizes many of the bioloqical effects of endorphins without altering analgesia (5). Therefore. we have been studying the neuro-endocrinal and urological aspects of TR H administration in the acute and chronic cases of spinal cord injury (6.7.8.9).