Salivary Markers of Stress in Grandparents Rearing Grandchildren in Rural Appalachia: The Role of Mental Health, Religiosity, and Social Support.

This study examines changes in salivary cortisol and alpha-amylase among grandparents rearing grandchildren in rural Appalachia. Grandparent-caregivers experience greater stress than non-grandparent-caregivers. Participants included 20 grandparent-caregivers and a child for which they cared, who completed questionnaires assessing family functioning and mental health via interview. Grandparent-caregivers provided morning saliva samples once a year for two years. For grandparent-caregivers low in social support and religiosity, grandparent-caregiver depressive symptoms, child depressive symptoms, and child stress were associated with increased grandparent-caregiver salivary alpha-amylase. For grandparent-caregivers high in social support and religiosity, child depressive symptoms, child stress, and child aggression were associated with increased grandparent-caregiver cortisol.

Associations between hair and salivary cortisol, salivary alpha-amylase, and temperament dimensions among 3-6-year-olds.

Associations between hair cortisol concentration (HCC), diurnal salivary cortisol (sCort) and alpha-amylase (sAA), and temperament dimensions were examined among 3-6-year-old Finnish children (n = 833). Children's hair samples were collected at preschool, while parents collected five saliva samples from children during one weekend day and completed a questionnaire assessing child's temperament dimensions i.e. surgency, negative affectivity, and effortful control (HCC, n = 677; AUCg of sAA, n = 380; AUCg of sCort, n = 302; temperament dimensions, n = 751). In linear regression analysis, diurnal sCort associated positively with HCC, the association persisting after adjustments (ß 0.31, 95% CI 0.20-0.42). In logistic regression analysis, increasing scores in effortful control associated with higher likelihood of having high HCC (OR 1.47, 95% CI 1.07-2.03), the association slightly attenuating to non-significant after adjustments. Otherwise, no clear indication for associations between temperament and stress-related biomarkers were found.

Covariation of psychobiological stress regulation with valence and quantity of social interactions in everyday life: disentangling intra- and interindividual sources of variation.

While the overall effects of social relationships on stress and health have extensively been described, it remains unclear how the experience of social interactions covaries with the activity of psychobiological stress in everyday life. We hypothesized that the valence as well as quantitative characteristics of social interactions in everyday life would attenuate psychobiological stress. Sixty healthy participants provided data for the analyses. Using an ecological momentary assessment design, participants received 6 prompts on their smartphone for 4 days. At each prompt, they reported on social interactions since the last prompt (any occurrence, frequency, duration, quality, and perceived social support), current subjective stress, and provided one saliva sample for the analyses of cortisol (sCort) and alpha-amylase (sAA). Experiencing any contact within days as well as higher daily levels of contact quality and perceived social support were associated with reduced levels of sCort. Furthermore, on a daily level, experiencing at least one contact in-between prompts more often as well as having more contacts on average attenuated the sAA output. Perceived social support and contact quality as well as higher daily contact durations were associated with lower subjective stress. For sCort, daily levels of stress moderated the effects of experiencing any contact within days while daily perceived social support moderated the effects of subjective stress. For sAA, experiencing at least one contact in-between prompts more often on a daily level moderated the effects of subjective stress. There were no between-person effects throughout all analyses. The results show ecologically valid evidence for direct attenuating effects of social interactions on psychobiological stress as well as for the stress-buffering hypothesis in everyday life. Increasing the quantity and improving the valence of social interactions on an intrapersonal level can possibly reduce psychobiological stress and prevent its consequences.

Associations between religious and spiritual variables and neuroimmune activity in survivors of breast cancer: a feasibility study.

PURPOSE: Chronic stress is associated with neuroimmune inflammation and adverse outcomes in breast cancer survivors. Some breast cancer survivors rely on religious and spiritual (R/S) variables to manage stress after breast cancer treatment. A spiritually based psychoneuroimmunological (PNI) model of health suggests that R/S variables influence neuroimmune activity; however, these associations are not well-established. A pilot study was conducted to assess the feasibility of studying associations between R/S variables and neuroimmune biomarkers in breast cancer survivors. METHOD: Salivary alpha-amylase (sAA) and interleukin-6 (IL-6) were sampled among women previously treated for breast cancer. The primary aim was to assess feasibility and acceptability of the sampling protocol. A secondary aim explored associations between sAA, IL-6, R/S variables, and health outcomes. RESULT: Forty-one women completed the study. Biomarker sampling yielded 246 acceptable specimens used for analysis. SAA was detectable in 96% of specimens and IL-6 was detectable in 44% of specimens. The R/S variables with the strongest associations to sAA were spiritual self-rank (rs = .39; p < .05) and forgiveness (rs = .40; p < .05). The R/S variable with the strongest association to salivary IL-6 was positive congregational support (rs = .42; p < .05). CONCLUSION: Feasibility and acceptability of the sampling protocol were confirmed. Reference ranges for sAA and IL-6 for female breast cancer survivors are presented. Results suggest that spiritual beliefs and religious practices are associated with neuroimmune activity, adding credence to a spiritually based PNI model of health. Findings lay the foundations for future R/S-based interventions to promote health and well-being in breast cancer survivors.

Frontal Electroencephalogram Alpha Asymmetry during Mental Stress Related to Workplace Noise.

This study aims to investigate the effects of workplace noise on neural activity and alpha asymmetries of the prefrontal cortex (PFC) during mental stress conditions. Workplace noise exposure is a pervasive environmental pollutant and is negatively linked to cognitive effects and selective attention. Generally, the stress theory is assumed to underlie the impact of noise on health. Evidence for the impacts of workplace noise on mental stress is lacking. Fifteen healthy volunteer subjects performed the Montreal imaging stress task in quiet and noisy workplaces while their brain activity was recorded using electroencephalography. The salivary alpha-amylase (sAA) was measured before and immediately after each tested workplace to evaluate the stress level. The results showed a decrease in alpha rhythms, or an increase in cortical activity, of the PFC for all participants at the noisy workplace. Further analysis of alpha asymmetry revealed a greater significant relative right frontal activation of the noisy workplace group at electrode pairs F4-F3 but not F8-F7. Furthermore, a significant increase in sAA activity was observed in all participants at the noisy workplace, demonstrating the presence of stress. The findings provide critical information on the effects of workplace noise-related stress that might be neglected during mental stress evaluations.

Assessing the association of university stress and physiological reactivity with decision-making among students.

Compared with age-matched employees, university students report higher levels of chronic stress and this may affect their decision-making. The impact of chronic stress and physiological reactivity upon cognitive function is receiving more attention, but few studies have empirically assessed the associations of these variables concurrently. Our aim was to investigate if chronic student stress, as assessed by effort-reward imbalance (ERI) and overcommitment, and physiological reactivity, were related to decision-making. As measures of physiological reactivity, we collected salivary alpha-amylase (sAA) and continuously recorded heart rate variability (HRV) data from male students (n = 79) at pretest and immediately after some computerized decision-making tasks (simple and choice- reaction times). Our findings suggest that students who are higher in overcommitment and who are more physiologically reactive (sAA and HRV indices) at the pretest stage may be more "at-risk" of poor decision-making than others. If others can replicate our findings in more diverse samples, this will contribute to an evidence base for interventions targeted at reducing overcommitment, ERI, and dysregulated autonomic reactivity to improve decision-making.

Neuroendocrine coordination and youth behavior problems: A review of studies assessing sympathetic nervous system and hypothalamic-pituitary adrenal axis activity using salivary alpha amylase and salivary cortisol.

Externalizing and internalizing behavior problems can have deleterious psychosocial consequences for youth. Both sympathetic nervous system (SNS) and hypothalamic-pituitary adrenal (HPA) axis activity and reactivity may contribute to behavior problems but have largely been studied separately, with inconsistent findings. Because the SNS and HPA axis interact to carry out physiological processes (e.g., responding to stressors), considering SNS and HPA axis activity jointly may elucidate disparate findings. This review discusses studies that simultaneously assessed SNS and HPA axis (re)activity and youth behavior problems using measures of salivary alpha amylase (sAA) and salivary cortisol. Multiple patterns of SNS and HPA axis coordination were associated with problem behaviors, especially when considering individual differences and youth's psychosocial context. Importantly, many study findings may be artifacts of widespread methodological differences. The reviewed studies lay the foundation for future research on neuroendocrine coordination as a contributing factor to youth problem behaviors and some recommendations for future research are discussed.

Salivary Alpha-Amylase as a Biomarker of Stress in Behavioral Medicine.

In recent years, research in behavioral medicine has become increasingly focused on understanding how chronic and acute exposure to stress impacts health outcomes. During stress, the body's physiological stress systems are activated. These systems closely interact with the immune system and are, thus, importantly implicated in the onset and maintenance of disease states. While much of the research in behavioral medicine that has investigated the effects of stress on disease has focused on the role of the hypothalamic-pituitary-adrenal axis and its downstream biomarker, cortisol, it is evident that the autonomic nervous system (ANS) also plays a crucial role in both the biological stress process and the manifestation and maintenance of stress-related symptoms. In recent years salivary alpha-amylase (sAA) has emerged as a valid and reliable marker of ANS activity in stress research and is therefore an important biomarker to consider in behavioral medicine. In this commentary, we will highlight research relevant for behavioral medicine that has utilized sAA measurements, both basally, and in response to stress, to examine ANS function in clinical populations. We will additionally summarize findings from studies that have examined the effects of various targeted interventions on changes in sAA levels. Through this, our aim is to present evidence that sAA can serve as a feasible biomarker of ANS (dys)function in health and disease. To this end, we will also highlight important methodological considerations for readers to keep in mind when including sAA assessments in their own studies. The overarching goal of this brief commentary is to highlight how a multidimensional approach toward physiological stress measurement can allow researchers to develop a better understanding of physical health and disease states.

Variation of human salivary alpha-amylase proteoforms in three stimulation models.

OBJECTIVES: To evaluate the sAA proteoforms' expression during different stimulation situations. MATERIALS AND METHODS: This study evaluated the salivary alpha-amylase (sAA) proteoforms' behavior by western blot (WB) analysis and high-resolution mass spectrometry (LC-MS/MS) in different situations that produce increases in sAA activity. For this purpose, six healthy women with a similar body mass index, age, and fit, underwent different sAA stimulation tests, such as acetic acid stimulation, psychological stress using the standardized Trier social stress test, and physical effort using the Cooper treadmill test. RESULTS: The three models showed an increase in sAA activity. The WB demonstrated seven common bands observed in the six women (band one at 59 kDa, two at 56 kDa, three at 48 kDa, four at 45 kDa, five at 41 kDa, six at 36 kDa, and seven at 14 kDa), in which sAA protein was identified. The individual WB analysis showed that band two, which corresponded to the native non-glycosylated sAA proteoform, had a higher increase after the three sAA stimulation inducers, and this band was also the only proteoform correlated with sAA activity (r = 0.56, P = 0.001). In addition, when the label-free quantification analysis was performed, the different proteoforms showed different responses depending on the type of stimulation. CONCLUSIONS: This preliminary study showed that the diverse sAA proteoforms' expression depends on the different stimulation models. CLINICAL RELEVANCE: This study opens new perspectives and challenges for the use of the different alpha-amylase proteoforms as possible biomarkers in addition to the sAA activity.

Pilot Study on the Effect of Biophysical Therapy on Salivary Alpha-Amylase as a Surrogate Measure of Anxiety/Stress: In Search of a Novel Noninvasive Molecular Approach for the Management of Stress.

Anxiety and depression impact dramatically on public health, underlying the importance of alternative cost-effective treatments. Previous studies have shown that biophysical treatment can significantly reduce anxiety symptoms and recently, salivary alpha-amylase (SAA) has been identified as an objective correlate of the sympathetic-parasympathetic imbalance related to increased stress burden, defined as allostatic load. The aim of this study was to evaluate the effect of biophysical therapy on SAA levels, in addition to the Depression Anxiety Stress Scale (DASS)-21 questionnaire. Twenty-four workers (sales representatives) presenting with mild anxiety/stress symptoms (Generalized Anxiety Disorder 7-item scale of > 5) were randomized to biophysical treatment (N = 12) or placebo control (N = 12). The biophysical group underwent electromagnetic information transfer through an aqueous system procedure, with daily self-administration for one month. SAA collection and the DASS-21 questionnaire were undertaken at baseline and after one month in all patients. Clinical characteristics and baseline DASS-21 subscale scores were similar between placebo and biophysical group at baseline. After one month, patients receiving biophysical therapy had significantly reduced SAA levels compared to the placebo group (27.8 ± 39.4 vs. 116.8 ± 114.9 U/mL, p = 0.019). All three DASS-21 subscales, depression (9.3 ± 5.1 vs. 5.7 ± 5.5, p = 0.1), anxiety (6.7 ± 25 vs. 3.7 ± 2.2, p = 0.0049) and stress (10.8 ± 4.2 vs. 7.3 ± 3.7, p = 0.041) were also decreased after biophysical treatment compared to placebo after one month. Our findings suggest that biophysical therapy can benefit workers with mild (subclinical) anxiety/stress. These results were also validated by the concomitant reduction of SAA levels and an improvement in DASS-21 subscales. The underlying molecular mechanisms of this therapy remain to be characterized.

Salivary α-Amylase Activity and Starch-Related Sweet Taste Perception in Humans.

Starch-related sweet taste perception plays an important role as a part of the dietary nutrient sensing mechanisms in the oral cavity. However, the release of sugars from starchy foods eliciting sweetness has been less studied in humans than in laboratory rodents. Thus, 28 respondents were recruited and evaluated for their starch-related sweet taste perception, salivary alpha-amylase (sAA) activity, oral release of reducing sugars, and salivary leptin. The results demonstrated that a 2-min oral mastication of starchy chewing gum produced an oral concentration of maltose above the sweet taste threshold and revealed that the total amount of maltose equivalent reducing sugars produced was positively correlated with the sAA activity. In addition, respondents who consistently identified the starch-related sweet taste in two sessions (test and retest) generated a higher maltose equivalent reducing sugar concentration compared to respondents who could not detect starch-related sweet taste at all (51.52 ± 2.85 and 29.96 ± 15.58 mM, respectively). In our study, salivary leptin levels were not correlated with starch-related sweet taste perception. The data contribute to the overall understanding of oral nutrient sensing and potentially to the control of food intake in humans. The results provide insight on how starchy foods without added glucose can elicit variable sweet taste perception in humans after mastication as a result of the maltose generated. The data contribute to the overall understanding of oral sensing of simple and complex carbohydrates in humans.

An experimental investigation into cardiovascular, haemodynamic and salivary alpha amylase reactivity to acute stress in Type D individuals.

Type D personality is characterized by increased social inhibition and negative affectivity. Research demonstrates associations between Type D and poor physical health. Maladaptive sympathetic arousal is suggested as a potential mechanism, however, findings are inconsistent and studies mainly focus on basic cardiovascular parameters. The current study examines cardiovascular and haemodynamic parameters in addition to salivary alpha amylase (sAA) as markers of sympathetic stress reactivity in Type D individuals. Healthy adults (N = 75; 33 Type D; aged 18-42; 64% female) completed a multitasking stressor while continuous beat-to-beat cardiovascular function was measured. Saliva samples were obtained at baseline, pre-task, post-task, +10 min and +20 min post-task. Type Ds exhibited dysfunctional cardiovascular reactivity, characterized by blunted total peripheral resistance, slower stroke volume recovery and potentially unhealthy changes in haemodynamic profile. Alpha amylase reactivity was evident, but group differences were not significant. Findings indicate dysregulated sympathetic reactivity in Type D individuals, exemplified by a maladaptive haemodynamic profile.

Association of salivary alpha-amylase and salivary flow rate with working memory functioning in healthy children.

The aim of this study was to examine the association between auditory and visual working memory (WM) performance and salivary alpha-amylase (sAA) and salivary flow rate (SFR) in a sample of 63 children (38 boys). WM was assessed by means of WISC-V subtests: four auditory subtests (Digit Span and Letter-Number Sequencing) and one visual subtest (Picture Span). SAA activity, output, and SFR were measured at baseline (10 min prior to testing), one minute prior to testing, one minute after the end of the auditory WM subtests and one minute after the end of the visual WM subtest. Our statistical analyses showed an association among SAA activity, output and SFR levels and the number of recalled digits in the last attempt score in Letter-Number Sequencing subtest. Specifically, our results showed that working performance in this task was associated with a concurrent decrease in SFR (r(63) = -0.423, p < .05). This salivary measure was the best predictor of this specific index of working memory performance (ß = -0.423, p < .05). These results show that the changes in SFR, which represents changes in parasympathetic tone, could be employed in future studies as a noninvasive marker of working memory performance in child studies.

The creative thinking cognitive process influenced by acute stress in humans: an electroencephalography study.

This study examined the underlying neural mechanism of acute stress affecting creative thinking. Twenty-six male participants underwent the Alternative Uses Test before and after acute stress test (Montreal Imaging Stress Task). Compared to before stress, stressed participants responded with higher salivary cortisol and salivary alpha-amylase. The electroencephalogram results indicated a general decrease in upper-frequency alpha power after stress, compared with that of before stress. The decrease in upper-frequency alpha power observed in the first stage after exposure to stress was related to memory and attention. Additionally, stress also reduced the differences between individuals with different creative abilities. In summary, these findings indicated that acute stress impaired creative thinking and primarily affected the earlier phase of the process of creative cognition. This study provides some practical implications for educational practice and corporate innovation in that a more relaxed environment promotes creative output. Lay Summary Acute stress impaired creative thinking performance and mainly affects the earlier phase of the process of creative cognition. Additionally, stress seems to reduce the differences between individuals with different creative abilities.

Attentional blink affected by acute stress in women: The role of affective stimuli and attentional resources.

The role of attentional resources and affective stimuli on temporal selective attention in the rapid serial visual presentation (RSVP) paradigm under acute stress was explored among women. Seventy-three female undergraduates were randomly assigned to the Trier Social Stress Test (TSST) group or control group. We found that when the first target was negative, stress increased its accuracy. Stress promoted the recognition of neutral target two (T2) only at lag2, and there was no interaction with theemotionality of target one (T1). In addition, the accumulated effect of stress enhanced temporal selective attention, predominately 20-40 min after the TSST task; cortisol concentration during this time period could significantly predict AB task performance. In summary, when attentional resources were severely insufficient, individuals under stress were more able to focus on the current target; that is, stress facilitated selective attention. A novel result was that participants were exempt from the affective influence of previous targets, which may have been caused by activation of the autonomic nervous system and gender differences.

Low subjective social status in the police is linked to health-relevant changes in diurnal salivary alpha-amylase activity in Swiss police officers.

The objective of this study was to assess basal autonomic nervous system (ANS) activity as a pathway linking subjective social status to health in a high-demand work environment. It was hypothesized that officers with a lower status experienced more chronic stress (higher basal ANS activity) and that chronic stress was related to more health problems. Fifty-six male and female Swiss police officers self-reported on subjective social status (country, community, friends, police) and their health (depression, post-traumatic stress, physical symptoms) and collected 12 saliva samples over two days for basal α-amylase activation (sAA) assessment. Multilevel regression analyses revealed that subjective social status in the police and physical symptoms explained a significant part of the variance in diurnal sAA activity patterns. The current findings support the idea that more narrowly defined subjective social status may be more closely linked to biological stress mechanisms. Additionally, sAA activity was specifically related to physical, but not mental health problems. These results suggest that subjective social status referencing one's work environment may be a promising early indicator of health-relevant changes in stress-related physiological systems.

Emotion regulation and positive affect in the context of salivary alpha-amylase response to pain in children with cancer.

BACKGROUND: Children with cancer routinely undergo painful medical procedures invoking strong physiological stress responses. Resilience to this pain may be conferred through resources such as emotion regulation strategies and positive affect. PROCEDURE: This study measured dispositional positive affect in children with cancer (N = 73) and randomly assigned participants to one of three emotion regulation strategy conditions (distraction, reappraisal, or reassurance). Children applied their assigned strategy during an experimental pain procedure (the cold pressor task [CPT]) and provided saliva samples before, immediately after, and 15 min after the CPT. Saliva samples were later assayed for salivary alpha amylase (sAA)-a surrogate marker for autonomic/sympathetic nervous system activity and regulation. RESULTS: Children in the reassurance group had sAA levels that continued to rise after completion of the CPT compared to children in the distraction (b = -1.68, P = 0.021) and reappraisal conditions (b = -1.24, P = 0.084). Furthermore, dispositional positive affect moderated the effect of condition such that children in the reassurance group with lower levels of positive affect had sAA levels that continued to rise after completion of the CPT (dy/dx = 1.56, P = 0.027), whereas children in the reassurance condition with higher levels of positive affect did not exhibit this rise (P > 0.05). CONCLUSIONS: Specific emotion regulation strategies, such as distraction and reappraisal, may attenuate the stress response to pain in pediatric patients with cancer, and positive affect may confer resilience in response to pain even with use of less effective coping strategies such as reassurance.

Changes in alpha-amylase activity, concentration and isoforms in pigs after an experimental acute stress model: an exploratory study.

BACKGROUND: Salivary alpha-amylase (sAA) is considered a non-invasive biomarker of acute stress that can be evaluated by changes in activity and concentration, and also by changes in its isoforms, although this last way of evaluation has never been used in veterinary medicine. This research evaluated the changes of sAA by three different ways in which sAA can be evaluated in an experimental acute stress model in six pigs based in a technique of temporarily restraining. These ways of evaluation were 1) activity by a spectrophotometric assay, 2) concentration by a fluorometric assay, and 3) isoforms of the enzyme by a Western blot. RESULTS: Although salivary cortisol significantly increased due to the stimulus of stress and all the pigs manifested signs of stress by high-pitched vocalization, sAA activity showed an increase of different degree in the six pigs after the stress stimulus, while sAA concentration showed decreases in four of the six pigs. sAA activity did not correlate with sAA concentration or salivary cortisol, and a low correlation was observed between sAA concentration and salivary cortisol (r = 0.48, p = 0.003). The inter-individual variability was higher in sAA activity than in sAA concentration and salivary cortisol. Finally, three possible isoforms of sAA at 154-160 kDa, 65-66 kDa and 59-60 kDa were observed that showed different dynamics after the stress induction. CONCLUSIONS: Although this pilot study's results should be taken with caution due to the low sample size, it reveals a different behavior between sAA activity and concentration in pig after an acute stressful stimulus leading to evident external signs of stress by high-pitched vocalization, and opens a new field for the evaluation of possible selected isoforms of sAA as potential biomarkers of stress.

Salivary alpha-amylase activity and cortisol in horses with acute abdominal disease: a pilot study.

BACKGROUND: The aim of this study was to evaluate salivary alpha-amylase (sAA), considered a non-invasive biomarker for sympathetic nervous system (SNS) activity, and salivary cortisol as possible pain-induced stress biomarker, in horses with acute abdominal disease. Therefore, a prospective observational study was performed in which both biomarkers were analyzed in a group of horses with acute abdomen syndrome, and compared with a group of healthy control horses by an unpaired Student's t-test. In addition, the possible relationship between both biomarkers, the score in Equine Acute Abdominal Pain scales version 1 (EAAPS-1 scale), Heart Rate (HR) and Respiratory Rate (RR), plasma lactate, the systemic inflammatory response syndrome (SIRS) score and serum amyloid A (SAA) concentration was assessed by a Spearman correlation test. RESULTS: A total of 30 horses were included in the study, 19 with acute abdominal disease diagnosed as large colon displacements, simple impactions of the pelvic flexure, spasmodic colics and enteritis and 11 healthy ones. sAA activity (24.5 median-fold, P <  0.0001) and salivary cortisol (1.7 median-fold, P <  0.01) were significantly higher in horses with acute abdomen than in healthy horses. sAA activity was significantly correlated with EAAPS-1 scale (r = 0.78, 95% confidence interval [CI] 0.38-0.89, P < 0.001) and SIRS score (r = 0.49, 95% CI 0.03-0.78, P < 0.05). Neither sAA nor salivary cortisol correlated with HR, RR, plasma lactate and SAA. CONCLUSIONS: Although this study should be considered as preliminary one, alpha-amylase measurements in saliva could be a biomarker of pain-induced stress in horses with acute abdominal disease.

Detection and measurement of alpha-amylase in canine saliva and changes after an experimentally induced sympathetic activation.

BACKGROUND: Salivary alpha-amylase (sAA) is considered a biomarker of sympathetic activation in humans, but there is controversy regarding the existence of sAA in dogs. The hypothesis of this study was that sAA exists in dogs and it could change in situations of sympathetic stimulation. Therefore, the aims of this study were: 1) to demonstrate the presence of alpha-amylase in saliva of dogs by Western-Blot, 2) to validate an spectrophotometric method for the measurement of sAA activity and 3) to evaluate the possible changes in sAA activity after the induction of an ejaculation in dogs which is known to produce a sympathetic activation. RESULTS: Western-Blot demonstrated a band in dog saliva specimens between 60 kDa and 50 kDa, similar to purified sAA. The spectrophotometric assay validated showed an adequate inter- and intra-assay precision, and a high correlation coefficient (r = 0.999) in the linearity under dilution study. sAA median activity significantly increased just after ejaculation compared with just before the ejaculation (2.06-fold, P = 0.005). CONCLUSIONS: This study demonstrated the existence of alpha-amylase in saliva of dogs and that this enzyme can be measured by a spectrophotometric assay. In addition, results showed that sAA increase after a sympathetic activation and could be potentially used as non-invasive biomarker of sympathetic activity in this species.