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.

Oxytocin is a neuropeptide with widespread influence on many physiological and social functions including: labor and birth, lactation, sexual behavior, nurturing maternal behaviors, and stress reduction. However, our understanding of oxytocin's roles has been hampered by lack of noninvasive methods for assessing oxytocin levels. The goal of the present study was to assess whether oxytocin could be detected in saliva and whether changes occurred in the pattern of oxytocin release among lactating women from before, at initiaton and after breast feeding. Using a prospective repeated measures design, 11 research participants each provided 18 saliva samples during three feeding cycles (before, at initiation and after breast feeding) for two 24-hour data collection periods (Day 1 and 2). Within each day, saliva was collected at late evening, early morning, and late morning. Salivary samples were concentrated four-fold by dehydration prior to analysis and oxytocin was measured in saliva using an enzyme immunoassay (EIA). Salivary oxytocin values, when reconverted to their original levels, ranged from 6.44 -61.05 pg/ml. Oxytocin values in saliva varied significantly as a function of the breast feeding cycle, but did not show reliable differences as a function of the time of feeding. Oxytocin was highest before feeding, followed by a decrease at initiation of feeding, and an increase at 30 minutes after feeding. The findings suggest that oxytocin release into saliva increases in anticipation of feedings. This study also supports the potential usefulness of salivary measures of oxytocin as a noninvasive index of changes in this peptide.

Oxidative stress occurs when there is an imbalance between free radical production and antioxidant capacity. This may be due to increased free radical formation in the body and/or loss of normal antioxidant defenses. Oxidative stress has been associated with the development of cardiovascular disease. The role of antioxidants in the primary and secondary prevention of coronary heart disease is currently under study. Although epidemiologic evidence indicates that antioxidants may decrease cardiovascular risk, clinical trial data are not conclusive. Information regarding the use and benefits of antioxidants in persons with diabetes is limited. Persons with diabetes may be more prone to oxidative stress because hyperglycemia depletes natural antioxidants and facilitates the production of free radicals. In addition, other factors such as homocysteine, insulin resistance, and aging may be contributory. This article highlights landmark clinical trials that have examined the cardioprotective effect of antioxidants. Because these trials have not been designed to study persons with diabetes, and clinical trial data for this group are not available, correlational studies are also presented. Finally, the concept of oxidative stress, the antioxidant and pro-oxidant factors that may contribute to oxidative stress, and the consequences of oxidative stress in persons with type 2 diabetes are presented. Key words: antioxidants, clinical trials,