Drop Date: January 2012
SBB – Novel Salivary Biomarkers of ANS Activity
In This Drop: Salivary Biomarkers of ANS Activity
Many studies in the behavioral and developmental sciences now utilize a multiple-biomarker approach. For example, salivary cortisol and salivary alpha-amylase (sAA) are often measured together as markers of activity in the hypothalamic-pituitary-adrenal axis (HPAA) and autonomic nervous system (ANS), respectively. Since these two systems are physiologically linked as part of the larger stress response system, measuring both biomarkers together should help researchers as they try to understand the ways that the two systems interact, and, ultimately, how these interactions are related to human health and development. (Bauer, et al. 2002; Gordis, et al. 2006; El-Sheikh, et al. 2008)
In order to probe the relationships between components of the stress system, bio-behavioral researchers often observe the reactivity of biomarkers such as cortisol and sAA to standardized laboratory stressors that include various physical, mental, and social components. In view of the complex and varied nature of the ANS response to stress, (Caccioppo, 1994; Cacioppo et al.,1998) it seems likely that researchers could benefit from the use of additional and/or more specific measures of ANS activity in their studies. Because saliva has been widely adopted as a non-invasive, practical testing medium that allows collection of biological samples in a wide range of settings, there is currently interest in determining whether additional autonomic markers can be identified in saliva.
The belief that additional ANS markers will be found in saliva is bolstered by the knowledge that both the composition and flow of saliva from the major human salivary glands are controlled by dual innervation from the sympathetic nervous system (SNS) and the parasympathetic nervous system (PNS). Saliva flow is largely controlled by the PNS and its main neurotransmitter acetylcholine (ACh), which binds to muscarinic receptors on the salivary cells. (Proctor & Carpenter, 2007) As the flow of saliva increases, changes in its ionic composition and pH also occur. (Catalán et al., 2009; Neyraud et al., 2009; Dawes & Jenkins, 1964; Dawes, 2008) Secretion of salivary proteins is largely controlled by the SNS through release of noradrenaline (NAd), which binds to adrenergic receptors on the salivary cells. The PNS also controls some protein secretion either by itself (mucins from mucous cells), or in conjunction with the SNS (proteins from serous cells). (Proctor & Carpenter, 2007) Additionally, sympathetic and parasympathetic nerves release a number of non-adrenergic, non-cholinergic (NANC) peptide transmitters such as vasoactive intestinal peptide (VIP) and neuropeptide Y (NPY), which also help regulate saliva flow and composition. (Ekström, 1999)
If changes related to the PNS (e.g., saliva flow rates, pH, neuropeptides associated with PNS) can be separated from those related to the SNS (e.g., secretion of serous proteins, neuropeptides associated with SNS), then it may be possible to gain useful information about activity in both systems through a common saliva sample. Although additional research needs to be carried out to explore candidate analytes, our initial attention is focused on seven markers related to ANS activity that can be measured in saliva: sAA, chromogranin A (CgA), VIP, NPY, saliva flow rate, and saliva pH.
In this issue of the Salivary Bioscience Bulletin we feature three articles that involve examples of salivary proteins that are currently under consideration as biomarkers related to autonomic nervous activity: chromogranin A, and the neuropeptides VIP and NPY.
Information on the best methods to collect and handle saliva samples for the analysis of novel protein and peptide markers of ANS activity is limited. We therefore recommend a conservative approach.
*Salimetrics provides this information for research use only (RUO). Information is not provided to promote off-label use of medical devices. Consult full text of article.
Salivary Chromogranin A, but not a-Amylase, Correlates with Cardiovascular Parameters during High Intensity Exercise
Gallina, S., Di Mauro, M., D’Amico, M.A., D’Angelo, E., Sablone, A., Di Fonso, A., Bascelli, A., et al. (2011). Clin Endocrinol (Oxf), 75(6), 747-52.
This study found that salivary CgA and sAA seem to be regulated differently during high-intensity exercise. Salivary CgA, but not sAA, correlated with cardiovascular parameters during high intensity exercise, and salivary CgA was confirmed to be a marker of psychological stress related to physical activity. These results suggest that salivary CgA is a reliable marker of sympathoadrenal-medullary system activation.
Research Area: Stress, Behavior & Development
Focus: Autonomic Nervous System
Neuropeptides in the Saliva of Healthy Subjects
Dawidson, I., Blom, M., Lundeberg, T., Theodorsson, E., & Angmar-Månsson, B. (1997). Life Sci, 60(4-5), 269-78.
Five neuropeptides (Neuropeptide Y, Vasoactive Intestinal Polypeptide, Substance P, Neurokinin A, and Calcitonin Gene-Related Peptide) were measured in the saliva of healthy subjects. Saliva samples were collected by different techniques: whole resting saliva, whole paraffin-stimulated saliva, whole citric acid-stimulated saliva, and citric acid-stimulated parotid saliva. Results showed that neuropeptides are continuously released into saliva. Release of neuropeptides is increased with stimulation, but the increased volume of saliva dilutes their concentrations. Differences were observed based on the type of stimulation employed – muscular activity leads to a greater release than citric acid stimulation.
Research Areas: Saliva
Focus: Saliva Composition & Flow
REFERENCES & RELATED RESEARCH
- Bauer, A.M., Quas, J.A., & Boyce, W.T. (2002). Associations between physiological reactivity and children’s behavior: Advantages of a multisystem approach. J Dev Behav Pediatr, 23(2), 102‐113.
- Cacioppo, J.T. (1994). Social neuroscience: Autonomic, neuroendocrine, and immune responses to stress. Psychophysiology, 31(2), 113‐28.
- Cacioppo, J.T., Gerntson, G.G., Malarkey, W.B., Kiecolt‐Glaser, J.K., Sheridan, J.F., Poehlmann, K.M., Burleson, M.H., et al. (1998). Autonomic, neuroendocrine, and immune responses to psychological stress: The reactivity hypothesis. Ann N Y Acad Sci, 840, 664‐73.
- Catalán, M.A., Nakamoto, T., & Melvin, J.E. (2009). The salivary gland fluid secretion mechanism. J Med Invest, 56(Suppl), 192‐96.
- Dawes, C. & Jenkins, G.N. (1964). The effects of different stimuli on the composition of saliva in man.J Physiol, 170, 86‐100.
- Dawes, C. (2008). Salivary flow patterns and the health of hard and soft oral tissues. J Am Dent Assoc, 139(Suppl), 18S‐24S.
- Ekström, J. (1999). Role of nonadrenergic, noncholinergic autonomic transmitters in salivary glandular activities in vivo. In: J.R. Garrett, J. Ekström, L.C. Anderson (Eds.), Neural Mechanisms of Salivary Secretion (pp. 94‐130), Basel: Karger.
- El‐Sheikh, M., Erath, S.A., Buckhalt, J.A., Granger, D.A., & Mize, J. (2008). Cortisol and children’s adjustment: The moderating role of sympathetic nervous system activity. J Abnorm Child Psychol, 36(4), 601‐11.
- Gordis, E.G., Granger, D.A., Susman, E.J., & Trickett, P.K. (2006). Asymmetry between salivary cortisol and α‐amylase reactivity to stress: Relation to aggressive behavior in adolescents. Psychoneuroendocrinology, 31(8), 976‐87.
- Neyraud, E., Heinzerling, C.I., Bult, J.H., Mesmin, C., & Dransfield, E. (2009). Effects of different tastants on parotid saliva flow and composition. Chem Percept, 2(2), 108‐16.
- Proctor, G.B. & Carpenter, G.H. (2007). Regulation of salivary gland function by autonomic nerves. Auton Neurosci, 133(1), 3‐18
*Note: Salimetrics provides this information for research use only (RUO). Information is not provided to promote off-label use of medical devices. Pease consult the full-text article.