Publication: Pineal opioid receptors and analgesic action of melatonin
Issued Date
1998-01-01
Resource Type
ISSN
07423098
Other identifier(s)
2-s2.0-0031976633
Rights
Mahidol University
Rights Holder(s)
SCOPUS
Bibliographic Citation
Journal of Pineal Research. Vol.24, No.4 (1998), 193-200
Suggested Citation
Manuchair Ebadi, Piyarat Govitrapong, Pansiri Phansuwan-Pujito, Francine Nelson, Russel J. Reiter Pineal opioid receptors and analgesic action of melatonin. Journal of Pineal Research. Vol.24, No.4 (1998), 193-200. doi:10.1111/j.1600-079X.1998.tb00532.x Retrieved from: https://repository.li.mahidol.ac.th/handle/20.500.14594/18323
Research Projects
Organizational Units
Authors
Journal Issue
Thesis
Title
Pineal opioid receptors and analgesic action of melatonin
Abstract
Physicians have noted since antiquity that their patients complained of less pain and required fewer analgesics at night times. In most species, including the humans, the circulating levels of melatonin, a substance with analgesic and hypnotic properties, exhibit a pronounced circadian rhythm with serum levels being high at night and very low during day times. Moreover, melatonin exhibits maximal analgesic effects at night, pinealectomy abolishes the analgesic effects of melatonin, and mu opioid receptor antagonists disrupt the day-night rhythm of nociception. It is believed that melatonin, with its sedative and analgesic effects, is capable of providing a pain free sleep so that the body may recuperate and restore itself to function again at its peak capacity. Moreover, in conditions when pain is associated with extensive tissue injury, melatonin's ability to scavenge free radicals and abort oxidative stress is yet another beneficial effect to be realized. Since melatonin may behave as a mixed opioid receptor agonist-antagonist, it is doubtful that a physician simply could potentiate the analgesic efficacy of narcotics such as morphine by coadministering melatonin. Therefore, future research may synthesize highly efficacious melatonin analogues capable of providing maximum analgesia and hopefully being devoid of addiction liability now associated with currently available narcotics.