The Oxford Biblical Studies Online and Oxford Islamic Studies Online have retired. Content you previously purchased on Oxford Biblical Studies Online or Oxford Islamic Studies Online has now moved to Oxford Reference, Oxford Handbooks Online, Oxford Scholarship Online, or What Everyone Needs to Know®. For information on how to continue to view articles visit the subscriber services page.

Related Content

More Like This

Show all results sharing this subject:

  • Science and technology


Show Summary Details



Quick Reference


one of a group of peptides that occur naturally in the brain and have pain-relieving properties similar to those of the opiates. See also encephalin.

Reference entries

View all reference entries »