Discussing the six meridional diseases of Shanghan Lun based on stress theory

Liang-Jun Yang, Ya Li, Dao-Rui Hou, Zhi-Peng Hu, Yong Zhang

1 Pi-Wei institute, Guangzhou University of Chinese Medicine, Guangdong, China；

2 Obstetrics and Gynecology Department, Lin’an Hospital of Traditional Chinese Medicine,Zhejiang, China；

3 Department of TCM Oncology, The First People's Hospital of Xiangtan City, Hunan, China；

4 School of Basic Medicine, Chengdu University of Traditional Chinese Medicine, Chengdu,China；

5 Pi-Wei department, Sichuan Second Hospital of Traditional Chinese Medicine, Chengdu,Sichuan China.

Abstract As the theoretical source of Traditional Chinese Medicine clinical medicine, Shanghan Lun plays a vital role in guiding the diagnosis and treatment of clinical diseases. Stress is a systemic nonspecific and adaptive response that occurs when the body is stimulated by internal and external environmental factors. This paper discusses the correlation between the three phases of stress containing alarm, resistance, and exhaustion and the three yin and three yang diseases. It was concluded that sanyang diseases were related to the alarm stage and resistance stage, and sanyin diseases were related to the failure stage. The results indicated the essence of diseases of six meridians from the perspective of stress and provided reference for the diagnosis and treatment of six classics diseases.

Key words: Shanghan Lun, Stress, Six meridional diseases, Three yin diseases, Three yang diseases

Background

As the theoretical source of Traditional Chinese medicine (TCM) clinical medicine, shanghanlun plays an important role in the establishment of syndrome differentiation theory of TCM [1].Among them, the three yin and three yang of six meridians, as the program of syndrome differentiation, could summarize and classify the clinical complex exogenous disease syndromes,so that the clinical diagnosis and treatment of exogenous diseases have owned a basis. Due to doctors' different academic backgrounds and eras, there are also differences in the understanding of six meridians. Some scholars advocate "meridian theory" [2], and some advocate "Zang-fu meridian theory" [3], and some advocate "gasification theory" [4]. There are also some who advocate "ground theory" [5].With the development of modern medicine, it has become a trend to interpret the six meridians from the perspective of modern medicine. The representative theories are "syndrome theory"[6], "pathological neurodynamic theory" [7],"pathological level theory" [8], "nervous system excitation inhibition theory" [9], "link theory"[10], and so on. These theories explain the essence of the six meridians from different angles, which is an innovation of the six meridians [11], and is helpful for us to further understand the six meridians.

Stress is a systemic non-specific adaptive response when the biological body is stimulated by internal and external environmental factors,and social and psychological factors. It is an important defensive response of the body to adapt to the changes of internal and external environment and psychosocial stimulation [12].In Shanghan Lun, external contraction as an external stimulating factor, is the basis for the occurrence of greater yang, lesser yang, yang brightness, greater yin, lesser yin and jueyin diseases, and is also the key to induce various diseases of Hebing and Bingbing in the body.At the same time, the body is bound to appear the corresponding stress response to resist and reduce the harm to the body, so the stress response runs through the overall development process of the six meridians disease. This paper discussed the relationship between stress and the transmission of six meridians, so as to provide reference for elucidating the modern medical mechanism and the diagnosis and treatment of six meridians.

“Shanghan” and stressor

Shanghan Lun was written in the late Eastern Han Dynasty. Under the social background of war, natural disasters and population migration,exogenous diseases have become the main cause of death. Therefore, Zhang Zhongjing's preface to the book states: "Since the year of Jian'an, two out of three of the population have died in less than ten years. And typhoid fever accounts for seven out of ten deaths [13]". We could definitely see that the important role of external contraction in the pathogenesis of the disease at that time. Shanghan Lun is named after"Shanghan" (typhoid fever) that can be divided into broad sense and narrow sense. Typhoid fever in broad sense refers to all exogenous febrile diseases, while typhoid fever in narrow sense refers only to be attacked by windcold [14]. As a monograph on the treatment of exogenous diseases, shanghanlun not only discusses the treatment of typhoid fever in a narrow sense, but also deals with the diagnosis and treatment of exogenous fever in a broad sense, which pioneers the rise of the school of febrile diseases in later generations. So shanghan is supposed to be regarded as typhoid fever in a broad sense.

The stimuli that cause stress are called stressors, which can be roughly divided into three categories: external environmental factors,internal environmental factors and psychosocial factors. The external environmental factors include cold, heat, dryness, humidity and other physical stimuli including bacteria, viruses and other pathogens. In the pathogenesis of typhoid fever, the etiology can be divided into the qi of four seasons for diseases and the qi of the time for diseases. The qi of four seasons for diseases is that the human bodys get sick in the touch of too much gas (specially wind-cold) under the normal climate change. The prevailing gas for diseases occurs under the abnormal climate change, which is an important cause of the epidemic and transmission of the disease. From the point of stress, the former can be regarded as cold, heat, dryness and dampness physical stressors, and the latter can be regarded as various pathogenic microorganisms. Both of them can be regarded as external environmental stressors, and the bodys show the syndromes of three yang and three yin diseases after "typhoid fever". It can be regarded as the stress response of the human body under the stimulation of stressors.

Three yang diseases and stress

Zhongjing named the book by "Shanghan",and used the outline of six meridians including three yin and three yang, showing the human bodys' differences caused by loss of treatment,mistreatment, or differences in the physique of patients after external contraction. In Shanghan Lun, three yang diseases refers to the three diseases of the greater yang, yang brightness and lesser yang. When the three yang get sick,the body is exuberant, disease resistance ability is strong, and evil qi is prosperous. This kind of diseases generally presents a hyperactive state, so three yang diseases belong to the heat syndromes and excess syndromes. Among them,the greater yang diseases are located in the body surface, so Shanghan Lun takes "pulse floating,stiffness and ache in the head of department and aversion cold" as the outline of greater yang diseases at the beginning of the chapter. If this pulse syndrome appears in the initial stage of exogenous fever disease, it can be called greater yang disease. Yang brightness is full of qi and blood, and it tends to be dry. So when exogenous fever progresses from the surface into the inside,it generally tends to be dry, and shows interior excess and heat syndromes. Therefore it is also said: "Yang brighterness belong to sthenic gastrointestinal syndrome." Lesser yang is as the pivot. When diseases into lesser yang, they are between the half surface and half li, which are not only away from the greater yang's surface,but also not into yang brighterness. So lesser yang diseases belong to half-exterior and half interior syndromes.

Shanghan Lun saids: "Lesser yang disease syndromes have oral bitterness, dry pharynx,and giddiness". Although the three yang (greater yang, yang brightness, lesser yang) diseases are full of evil qi, there also exists much of yang qi and healthy qi that is the leading factor of the body. In terms of treatment, resolving the exterior, clearing heat, and Valley Passage are often adopted for three yang diseases.

After the body is subjected by external stimulation, there will be a series of neuroendocrine responses to compensate for body damages. This process, which leads to various disorders and damages of the body,is called systemic adaptation syndrome [16].Systemic adaptation syndrome can be divided into three stages according to the length of stimulation time and adaptive response of stressors to the body: alert phase, resistance phase and exhaustion phase [17]. The alertness period appears after the body attracted by stressors, which is the rapid mobilization period of the body defense mechanism. The neuroendocrine response in this period is mainly the excitation of sympathetic-adrenal medulla system, accompanied by the increase of adrenocortical secretory. This period exists the change of active adaptation to stress, which is of positive significance to the body. During the resistance period, the body still actively adapts to the changes of the environment. At this stage,the main response of the body to sympatheticadrenal medulla excitation gradually subsides,the adrenal cortex begins to hypertrophy, and glucocorticoid secretion further increases. In this period, the resistance of the body to stressors is gradually enhanced, and the impact of stress on the body is further controlled by coordinating the neuroendocrine response. This is helpful to maintain the integrity of the physiological function of the body.

In the alarm period and resistance period of stress, these two periods are mainly to deal with the changes of external stimuli positively and actively in order to eliminate the damage of the environment to the body. We could understand it from the point of traditional Chinese medicine:these two stages of the human body are more exuberant, and are the periods of the struggle between right and evil qi (the right qi is the body's neuroendocrine response, and evil qi is the stressor). At the same time, we can also elucidate it from the symptoms of these three stages (greater yang, yang brightness, and lesser yang). At the stage of greater yang, the body is characterized by fever, chills, head pain and so on, which is exactly because sympatheticadrenal medulla secretion increases, human sympathetic nerve excites, and metabolism is high. At the same time, due to the peripheral blood vessels' sympathetic action and vasoconstriction, the body could show aversion to cold, and the head muscles could cramp due to the reduction of peripheral blood supply.In the stage of yang brightness, it is mainly manifested as polydipsia, fever, profuse perspiration, and defecation impassable. From the view of neuroendocrine response, these syndromes are mainly due to the excitation of sympathetic nerves, the increase of volume heat production, and the loss of body fluids.

At the same time, gastrointestinal peristalsis slows down influenced by the factors of sympathetic nerves and the glucocorticoid, so there is stool induration which is difficult to go down. In the stage of lesser yang, due to the body sympathetic nerve excitation, gland secretion reduction, and bile reflux, there are syndromes of elevated blood pressure, mouth pain, pharynx dry, dizziness syndrome. Thus it can be seen that the understanding of three yang meridians from the view of alarm period and resistance period of stress is not only in line with the understanding of the pathogenesis of three yang in TCM, but also in line with the interpretation of clinical symptoms of the diseases in Western medicine.

Three yin diseases and stress

In Shanghan Lun, three yin diseases refer to greater yin disease, lesser yin diseases and jueyin diseases. Greater yin dominates dampness, which depends on the warmth of the body's yang qi. When diseases tend into greater yin, spleen yang will be not transported,thus cold and dampness could be blocked in the middle energizer, and the body could show the spontaneous diarrhea, and intermittent abdominal pain. Lesser yin includes heart and kidney, most diseases of which are caused by heart-kidney deficiency and insufficiency of vital energy and blood. So the clinical manifestation of lesser yin diseases is "fine pulse, and only want to sleep". If yang deficiency is serious,there can be severe diseases such as clear-food diarrhea, cold hands and feet, and so on. The At this time the stages of two yin are over, yin is extreme and yang turns to return. And that's why it is called jueyin [18]. As the last stage of the six meridians, jueyin diseases often present the characteristics of upper heat and lower cold, cold-heat complex. Compared with three yang diseases, the three yin diseases location is interior, yin evil is prosperous, and the diseases’situation is quiet. Coupled with the weakness of vital qi, the disease resistance ability of the body is weakened. So most of three yin diseases are deficiency syndromes and cold syndromes, and the prognosis is worse than that of three yang diseases.

From the point of stress, the body will change from warning period and resistance period to exhaustion period after experiencing continuous and strong stressors. When the body's energy reserve and defense mechanism are exhausted, the pituitary gland and adrenal cortex will lose the ability to secrete hormones.Various organs can not adapt to the stimulation of stressors, resulting in a series of adaptive diseases, such as peptic ulcer, heart injury,shock and decreased resistance to infection and so on. Combined with the characteristics of three yin diseases, the pathophysiological characteristics of the weakening and decline of organ function in the exhaustion period can be regarded as the manifestation of the decline of vital qi in the human body. The body is still stimulated by external stressors at this stage, so the stressors can be regarded as exuberant evil qi. In the stage of greater yin, the body shows gastrointestinal symptoms of abdominal pain,vomiting and diarrhea, which can be understood as gastrointestinal dysfunction caused by stress.If there is no improvement in the situation,it can further develop into stress ulcer with gastrointestinal bleeding, which is the Huangtu Decoction of Shanghan Lun. In the stage of lesser yin, the diseases are characterized by aversion to cold, pulse rest and so on, which are mainly caused by the decrease of human metabolism,cardiac output and insufficient peripheral blood volume. In the treatments in shanghanlun, most diseases are treated with Zhenwu decoction.Modern pharmacological researches and clinical researches have proved that Zhenwu decoction has the effect of enhancing myocardial contractility and increasing cardiac output [19],and is corresponding to the body reactions of lesser yin diseases. In the stage of jueyin,although the body is decaying, but there is still a struggle between right and evil. At this time the result of this struggel determines the trend of the disease. Shanghan Lun saids: "Syncope is because yin and yang qi do not connect.Syncope is the syndrome of unfavourable cold of hand and foot". It can be understood as the exhaustion of energy reserve and defense mechanism after the body is stimulated by continuous and strong stressors, which makes the function of tissues and organs unabled to be compensated, and finally leads to shock. There is a difference between heat shock and cold shock which correspond to febrile syncope and cold syncope in TCM.

To sum up, there is a certain correlation between diseases of greater yin, lesser yin and jueyin and the stage of stress exhaustion.From the point of pathogenesis of TCM, the deficiency of vital qi in the body in three yin diseases belongs to yin syndromes, which is consistent with the recession metabolism and function of tissues and organs in the stage of stress exhaustion. On the other hand, at the stage of three yin, the symptoms of the body are also related to the performance of stress exhaustion period, and the prescriptions used also have a certain basis. Therefore, the understanding of three yin diseases from the point of stress failure period can provide the basis for the diagnosis and treatment of three yin diseases.

Conclusion

Stress, as a systemic non-specific adaptive response of organisms stimulated by internal and external environmental factors and social and psychological factors, plays an important role in maintaining the sound physiological and psychological functions of the body. Appropriate stress is helpful for the body to resist all kinds of sudden harmful events and reduce the damage to the body caused by external stimuli. But at the same time, too strong stress responses will also bring adverse effects on the body,which can make the body appear physical and mental damage [20]. Therefore, how to regulate the stress response of the body and reduce the damage caused by excessive stresses has become an important way to prevent and treat diseases.

As the program of TCM diagnosis, syndrome differentiation of six meridians is an important basis for clinical diagnosis and treatment.Therefore, it is of great significance for the modernization of TCM to clarify the essence of six meridional diseases by using the results of modern medical researches. The essence of TCM syndromes is the pathophysiological response of human body to disease [21], which involves the regulation of human neuroendocrine-immune network systems, and stress is closely related to this process. From the point of modern stress theory, this paper discussed the relationship between three yang diseases and three yin diseases and the stress respectively from the three phases of stress: alarm period, resistance period and exhaustion period. Therefore, it is concluded that three yang diseases are related to stress alarm period and resistance period, and three yin diseases are related to stress failure stage. We hope to elucidate the essence of six meridional diseases of Shanghan Lun from the perspective of stress, and provide references and ideas for the diagnosis and treatment of six meridional diseases in clinical practices.