Detection of enkephalin-like immunoreactive material in human saliva

1. A specific radioimmunoassay (RIA) was used to detect the presence of enkephalin-like activity in mixed saliva from healthy male and female human subjects, whose ages ranged from 20 to 30 and from 55 to 65 years. 2. Enkephalin-like immunoreactivity was measured in saliva from all subjects. Within the limits posed by the immunoassay no significant differences in levels were evident among the various groups. 3. The results of this study provide the first demonstration of opioid-like substances in saliva. 4. As the collection of saliva involves non-invasive techniques, this source may prove useful for monitoring enkephalin levels during various clinical procedures or experimental treatments.