"The Liver Should Be Spring, The Main Venting, Regulating Emotions" Theoretical And Experimental Research

Liver controlling dispersion and regulating emotion according to spring,a most important part of the theory of five viscera corresponding xwith time,is a branch of the ancient philosophical thinking named ’correspondence between man and nature’.A most important content in research of liver according to spring is to find the regulation mechanism of emotion appear in accordance with seasonal variation.1 ObjectiveTo reveal the scientific connotation of liver controlling dispersion and regulating emotion according to spring,we combined melatonin(MT)with hypothalamic-pituitary-adrenal axis(HPA axis)and hippocampus,which could provide theoretical and experimental basis of the prevention and treatment for emotional disorder.2 Method2.1 Theoretical studyLiterature review and logical and deductive analysis were applied in this section,to confirm the scientificity of theory of liver controlling dispersion and regulating emotion according to spring in physiology and pathology of the body.Discussion of liver controlling dispersion and regulating emotion according to spring was carried out to propose a regulatory mechanism in physiology.Which could be a theoretical basis for animal research.2.2 Animal study2.2.1 General design5 weeks old SD male rats were chosen as subjects to detect the variation of hormone and monoamine neurotransmitter in different seasons(the point-in-time was chosen as the Spring Equinox,the Summer Solstice,the Autumnal Equinox,the Winter Solstice),including MT,corticotropin-releasing factor(CRF).adrenocorticotropic hormone(ACTH),corticosterone(CORT),serotonin(5-HT),dopamine(DA),norepinephrine(NE).Relationship between seasonal variation and hormone secreted by pineal gland(PG)and HPA axis,as well as monoamine neurotransmitter in hippocampus,was discussed.The regulatory role of MT in HPA axis and hippocampus has been conferred.2.2.2 Experimental animal5 weeks old SD male rats in normal health,weighted 150～170 gram,were divided into 3 groups randomly,with 8 rats each group.Surgical operation of operative group(PG removed)and sham operative group(without PG removed)was finished 30 days before sacrificed.All rats were adopted with a natural light condition,while humidity at 50%～60%,temperature at 17±2℃ in winter,25±2℃ in summer.All rats were removed to dark chamber at dusk and sacrificed at 21:00 at the point-in-time.2.2.3 Determination of biochemical markersRadioimmunoassay(RIA)was applied to detect the expression of MT,CRF,ACTH,CORT,while enzyme-linked immunosorbent assay(ELISA)was applied to detect the expression of 5-HT,DA,NE.2.2.4 Statistical analysisThe data are presented as the mean ± standard error of the mean(n=8).The GraphPad Prism software package(GraphPad Software,California,USA)was applied to analyze the data.The statistical analyses among groups were performed by a one-way analysis of variance while data accorded with normal distribution and homogeneity of variance.If the data were not perfectly normally distributed,Mann-Whitney U test was applied to analyze the data,while missing variance with Welch method.Independent sample T test was applied to test the data between two groups.Differences for all tests were regarded as statistically significant when the P-value from a two-tailed test was less than 0.05.3 Results3.1 The expression of MT varied with light variation in normal physiological state.Which showed the lowest in summer,and highest in winter,while medium level in spring and autumn.3.2 HPA axis displayed a higher activity in spring and winter,while a lower activity in summer and autumn in normal physiological state.CRF showed a highest level in spring,a higher level in winter,a lowest level in autumn.ACTH showed a highest level in autumn,a lowest level in spring.CORT showed a highest level in winter,a higher level in spring,a lowest level in autumn.3.3 The expression of monoamine neurotransmitter in hippocampus displayed a seasonal variation in normal physiological state.5-HT showed a highest level in spring,a lowest level in summer.DA showed a highest level in winter,a lowest level in spring.NE showed a highest level in winter,a lowest level in autumn.3.4 MT showed seasonal regulating action to hormone of HPA axis and monoamine neurotransmitter in hippocampus.For regulation of HPA axis,after removing PG,CRF and ACTH showed a higher level in spring,ACTH showed a higher level,while CORT showd a lower level in summer,CRF showed a lower level,while CORT showd a higher level in autumn,CRF showed a lower level,while ACHT showd a higher level in winter.For regulation of monoamine neurotransmitter,after removing PG,5-HT and NE showed a lower level in spring,DA showed a higher level in summer,5-HT and DA showed a lower level in autumn,DA and NE showed a lower level in winter.The activity of HPA axis strengthened after PG removed in spring,lower the expression of 5-HT and NE.4 Conclusion4.1 There have seasonal rhythms in the hormone of HPA axis and monoamine neurotransmitter in hippocampus.4.2 The seasonal change of hormone of HPA axis and monoamine neurotransmitter in hippocampus is closely related to MT secreted by PG.A predilection for season and different level of hormone and monoamine neurotransmitter,as well as dissimilarity extent and dual-direction,was showed in the regulation of melatonin to expression of hormone of HPA axis and monoamine neurotransmitter in hippocampus.4.3 The theory of liver controlling dispersion and regulating emotion according to spring is achieved by the seasonal change of MT,who play a key role in the variation of hormone of HPA axis and monoamine neurotransmitter in hippocampus.All make the theory more scientific.Which may play a physiological and pathological role in seasonal affective disorder(SAD).