Detection Of α-Amylase Activity And Its Application In Stress Response Evaluation

"Father of Stress Theory"Selye defines stress as"the non-specific response of the body to internal/external environmental stimuli."When the human body is under stress,the three major systems of the nervous system,endocrine system,and immune system interact to produce a stress response,which will affect cognitive function and body health.One of the main mechanisms of action is through the sympathetic-adrenal-medulla(SAM)system.Changes in neuroendocrine when facing stress are the precursors and foundations of changes in other organ functions.Neuroendocrine changes under stress are intricate and complex.The substances closely related to stress include neurotransmitters and their receptors,immune factors,neuropeptides,stress proteins,and nucleic acids,etc.When the sympathetic nerve is excited,it is confirmed that a increased secretion of salivaryα-amylase will be observed,which is a bioactive marker of the sympathetic-adrenal medulla system,and the response speed is faster than cortisol,so theα-amylase activity level can be timely reflects the physical and mental functions of the human body and is closely related to changes in the autonomic nervous system during human stress.Alpha amylase is found throughout the body,including in body fluids such as saliva and breast milk.Under stress,it can be used to characterize the activity of sympathetic-adrenal gland system and to reflect autonomic nervous system function and activity.As the reliability and effectiveness of the technology in detection ofα-amylase is increasingly recognized,its research and application are becoming more and more extensive.This study mainly includes the following five aspects:(1)The correlation between air pollution stress and salivaryα-amylase in preschool children;(2)The synergy between SAM system and Hypothalamus-pituitary-adrenal(HPA)system of preschool children exposed to air pollution;(3)The characteristics of autonomic nervous system function in preschool children during classroom teaching;(4)The characteristics of autonomic nervous system function in persons under the stressful working environment;(5)The establishment of pretreatment and analytical method forα-amylase in human milk and its application in stress evaluation.1、The correlation between air pollution stress and salivaryα-amylase in preschool childrenIn order to investigate whether the salivaryα-amylase activity of preschool children can respond to the change of air pollution level,110 preschool children in two kindergartens(A and B)in Suzhou were selected.Through SPSS 20.0 analysis,the aerosols in A and B kindergartens was 117±28.6μg/m~3<153±35.4μg/m~3 respectively(P=0.003),and the salivaryα-amylase activity of preschool children was 324.3±69.1 U/ml<392.5±107.8 U/ml respectively(P=0.002),indicating that aerosols exposure can lead to increased stress level in preschool children.In addition,through association analysis of plasticizer level of aerosol in A and B kindergartens and scores collected from Family Questionnaire(self-made)filled by children’s parents,it was revealed that the degree of exposure to plasticizer would cause the increase of stress level in preschool children.It is speculated that air pollution will cause the children’s autonomic nervous system dysfunction,cognitive impairment,and other risks.2、The synergy between SAM system and HPA system of preschool children exposed to air pollutionSympathetic adrenomedullin system and hypothalamus pituitary adrenocortical system are the main stress response systems of human body.When the air pollution changes slightly,whether the characteristics of these two systems in children are clear needs to be further confirmed.Therefore,on the basis of the previous chapter.According to 110 school-age children in kindergartens A and B,combined with other research data of the research group,the results show that the urine cortisol and salivaα-amylase of children in kindergartens a are 21.3±9.9ng/ml,324.3±69.1U/ml(r=0.513,P=0.012),the urine cortisol and salivaα-amylase of children in kindergartens B are 35.5±14.6ng/ml,392.5±107.8U/ml(r=0.600,P=0.002).The results showed that the fine particulate matter exposure induced the positive stress response of SAM system and HPA system,suggesting that the regulatory functions of both systems were highly consistent,indicating that school-age children basically had the stress response model of adults.3、The characteristics of autonomic nervous system function in preschool children during classroom teachingIn order to effectively evaluate the changes of autonomic nervous system activity of preschool children attended different class,50 preschool children aged 6-7 were recruited.The results of salivaα-amylase detection showed that the group activity values of children before and after music class were 391.1±145.9 U/ml>328.6±140.5 U/ml(P=0.024),the group activity values of children before and after activity class were 300.4±125.0 U/ml<359.6±128.8 U/ml respectively(P=0.020),indicating that preschool children have different stress responses to different teaching contents.It is suggested that teaching/education workers should arrange teaching courses reasonably to improve teaching/education effect.4、The characteristics of autonomic nervous system function in persons under the stressful working environmentIn order to effectively evaluate the changes of autonomic nervous system activity of persons in different working environments,a volunteer was recruited to quantitatively characterize the different autonomic nervous system stress responses in different working environments by monitoring the changes of salivaryα-amylase activity in two specific working environments:noise and mobile phone radiation.It suggests the importance and necessity of reducing noise and cell phone radiation,and provides corresponding protection strategies for the healthy development of practitioners.5、The establishment of pretreatment and analytical method forα-amylase in human milk and its application in stress evaluationIn view of the serious matrix interference in the detection of breast milk samples,a pretreatment method based on saturated ammonium sulfate solution as a precipitant was established,which has good matrix removal effect and does not destroy the activity ofα-amylase.On this basis,the established visible light spectrophotometry has good linearity(linear equation:y=43954x-113.8;correlation coefficient:R~2=0.993;linear range:0-2800u/L),accuracy(recovery:82.9%～102.0%)and precision(intra day precision:RSD<5%;intra day precision:RSD<5%)which are in line with the requirements of analytical methodology.The evaluation of stress experiment showed that air pollution exposure may reduce the activity ofα-amylase in human milk(P=0.398).This method has the advantages of low cost,convenience and simplicity.It is suitable for the routine test ofα-amylase activity in human milk.