Oxytocin: behavioral associations and potential as a salivary biomarker

Oxytocin (OT) is a neuropeptide that is produced primarily in the hypothalamus and is best known for its role in mammalian birth and lactation. Recent evidence also implicates OT in social behaviors, including parental behavior, the formation of social bonds, and the management of stressful experiences. OT is reactive to stressors, and plays a role in the regulation of both the central and autonomic nervous system, including effects on immune and cardiovascular function. Knowledge of patterns of OT release would be of value in many fields of science and medicine. However, measurements of OT concentration in blood are infrequently performed, and previous attempts to measure OT in saliva have been unsuccessful. Using a sensitive enzyme immunoassay (EIA) and concentrated samples we were able to detect reproducible changes in salivary OT as a function of lactation and massage. These results indicate that measurements of biologically relevant changes in salivary OT are possible. These results confirm the biological relevance of changes in salivary OT with stressors and support saliva as a noninvasive source to monitor central neuroendocrine function.