Study On The Correlation Between Hypothalamic - Pituitary - Target Gland Axis Function And Cell Signal Transduction In "four Seasons Xue Yin Yang" Theory

"Correspondence between man and nature" theory is the basic character of Traditional Chinese Medicine(TCM), and Zang-Xiang theory is the main point of TCM theory. The "Four seasons-five organs-yin and yang" theory is a theory which aims to explore the essence of Zang-Xiang theory from time viewpoint and to seek out the regulation and influence on human physiology and pathology by environment, season change, growth and decline of yin and yang under the guidance of "Correspondence between man and nature ".1 ObjectiveThe study’s breakthrough was "Four seasons-five organs-yin and yang" theory, and the entry point was melatonin, and the study’s leading clue were HPAA and HPTA. Firstly, to make analysis for the "Four seasons-five organs-yin and yang" theory, then discussed the relationship between HPAA and the essence of Zang-Xiang theory in TCM. Contents of hormones in HPTA and HPAA along with melatonin, melatonin receptor (MR) and cell signal transduction system according to seasonal changes were put into experiment in order to explore the scientificity of "Zang-Fu correspond to time" theory.2 Research methods2.1 Theoretical study methodsThe study demonstrated the meaning of "Four seasons-five organs-yin and yang" theory, and made sense that the affect on human physiology and pathology given by seasons through literature survey. The correlation between HPAA and Zang-xiang theory was argued to prove the practice for its experiment.2.2 Experimental study methods2.2.1 General design:Taking climate in four seasons as cut-in point, choosing Golden hamster for experimental animal which is sensitive to the photoperiod. This study intended to show that the seasons can have effect on nerve-endocrine-immune in normal status all the year round. Many chemical index were tested, such as MT,MR,corticotropin releasing hormone (CRH), adrenocorticotrophic hormone (ACTH), corticosterone (CORT), arylalkylamine N-acetyltransferase (AANAT) and hydroxyindole O-methyltransferase (HIOMT) both in plasma and tissue of HPAA, others were MT, MR, thyrotropin-releasing hormone(TRH), thyroid-stimulating hormone(TSH), triiodothyronine(T3), tetraiodothyronine (T4) in HPTA. So were cAMP,PKA,c-fos,c-jun of cell signal transduction system in HPAA.2.2.2 Experimental animalThere were eight male Golden hamsters in each group, weighted (130±10) gram. All rats were adopted in the condition of controllable temperature and humility(18±2 degree in winter,25±2 degree in summer,50%-70% of humility) with natural light for two weeks before sacrificed. The rats were removed to darkroom at dusk and sacrificed at 22:00 at the spring equinox, the summer solstice, the autumnal equinox and the winter solstice,respectively.2.2.3 Index detectionsThe levels of MT, MR, CRH, ACTH, COR,cAMP,PKA,the activity of AANAT, HIOMT in HPAA, and the content of MT, MR, TRH, TSH, T3, T4 in HPT were checked by ELISA.And the MOD of c-fos and c-jun mRNA in HPAA were checked by the method of in situ hybridization.2.2.4 Statistical analysesThe SPSS 20.0 statistical software was applied. All data were expressed in the form of (x ± s). One-way ANOVA or non-parametric test were used to testify among groups, and T test with one independent sample or non-parametric test with two were applied between two groups. P<0.05 stands for statistical significance.3 Results3.1 The expressions of hormones in the HPAAIn physiological condition, the levels of MT and MR increased in spring and winter, but decreased in summer both in plasma level monitoring and tissue testing (including hypothalamus, adrenal gland tissues). And the results of CRH and CORT were the same, showing higher levels in spring and winter, but lower levels in summer (P<0.05). So was the plasma content of ACTH (P<0.01). Interestingly, the contents of MT,MR and ACTH in pituitary were higher in summer, but lower in winter(P<0.01).3.2 The content of cAMP and PKA of the HPAAThe contents of cAMP and PKA increased in spring and winter, but the least in summer and autumn, both in the hypothalamus and adrenal gland tissues. In the The pituitary gland, the content of PKA had the same trend, but the level of cAMP was just on the contrary.3.3 The expressions of c-fos and c-jun mRNA of the HPAAThe level of c-fos mRNA MOD of hypothalamus tissue decreased in autumn and winter,in pituitary tissue increased in autumn and winter,but in adrenal gland tissue the level was higher in summer and autumn.For c-jun mRNA, the level of MOD of hypothalamus and pituitary gland tissues both increased in winter and autumn,but in adrenal gland tissue the higher level appeared in winter and spring.3.4 The activity of AANAT and HIOMT (the restrict enzymes of melatonin synthesis in adrenal gland)In physiological condition, the contents of AANAT and HIOMT manifested dramatically higher in spring but lower in summer, and there was significant difference among the four seasons (P<0.05).3.5 The expressions of hormones in the HPTAThe levels of MT, TRH, TSH, T3 and T4 in plasma had the tendency to be higher in winter and spring or autumn, but lower in summer. However, the tendency was opposite in thyroid tissue, namely the contents were higher in summer, but lower in winter. There was significant difference between the highest and lowest groups (P<0.01).4 Conclusions4.1 The Chinese medicine "Four seasons-five organs-yin and yang" theory is based on the biological foundation.4.2 Seasonal rhythm exists in neuroendocrine system (both in the HPAA and HPTA). The functions of the two axes and the cell signal transduction system of HPAA have characteristics of varies with seasonal changes. This may be related to the regulation of melatonin.