• Title/Summary/Keyword: Korean dual system

Search Result 1,915, Processing Time 0.035 seconds

The Study of the Foundation of Establishing the Value of the Unification of the Korean Peninsula in Muliticultural Society of Korea -focused on a possibility of the mulitucultural conception of culture and emotion (한국 다문화 사회에서 한반도 통일의 가치정립의 토대에 대한 연구 -문화 개념과 정서 개념의 다문화적 접근의 가능성을 중심으로)

  • Song, Sun-Young
    • Journal of Ethics
    • /
    • no.80
    • /
    • pp.51-77
    • /
    • 2011
  • This study aims to explore how to establish any foundation of the value of the unification of the Korean Peninsula in multicultural society of Korea. Its main issue is related to Korean identity of a nation and its shared value among the mulitcultural members, in particular, of North Koreans including defectors, foreign workers, and immigrants of international marriage and their children. For this study, I would utilize a given research of the application of two concepts of culture to multicultural levels by criticizing its limit; as an alternative, furthermore, I would pay attention to the possibility of the concept of emotion in multicultural members. A short feature in a given study of two conceptions of culture in a multicultural society is as follows: the first is to regard it as the patterns of meanings and symbols, which is very useful to understand others or other culture; secondly, to see it as the lasting process of perfection in human life, which makes us recognize ourselves as a member, so to speak, identity. In application it to Korean muliticultural members, however, there are crucial and complicated problems according to the cases of their lives. For North Koreans, firstly, they tend to get the conception of Korean identity in terms of ideological policies and education of North Korean government. This means that they have a strong hatred towards the word multiculture, in the level of recognizing the self-culture. Secondly, North Korean defectors also have the recognition of the self-culture, but their serious problem is discriminative treatments by South Korean in terms of socio-economics, in the process of their settlement. Thirdly, parents and their children in multicultural family can have their identity as Korean. In parents, however, the level is double that they can have both identities of Korean as well as of their countries. The foundation, therefore, of the value of the unification in the Korean Peninsula is closely related to the issue of identity as Korean. To recognize it, it is possible only to consider and reflect all members' lives by applying the dual conceptions of culture to their multicultural lives. That is not of outer system, but of inner, relational and cultural emotion, which enables them to share their common value of unification.

The Present Situation and Future Strategies of 4-Year Nursing Baccalaureate Program (한국 4년제 대학 간호교육의 현황과 발전방안)

  • Park Jeong-Sook
    • The Journal of Korean Academic Society of Nursing Education
    • /
    • v.1 no.1
    • /
    • pp.17-23
    • /
    • 1995
  • One of the biggest problems of Nursing Education in Korea is the division among nursing education programs of the last 3 and 4 years. To solve this problem, Nursing community must do variable trials to achieve the unity of a 4-year educational program. With this, we need to observe the phenomena and reality of the present 4-year nursing educational program that we have. The object of this study is to analyse and discuss that we have. The object of this study is to analyse and discuss the problems and future strategies of 4-year Nursing Baccalaureate program. 1. Problems as nursing department in Medical School. 1) Many 4-year nursing baccalaureate programs are operating under the medical school as nursing department. So the academic development in nursing department is unprogressive and is not approved as unique discipline. 2) The operating system between nursing and medical department are different even though they are in the same school. 3) Inequality between nursing and medical department : In many case, the nursing professor can not attend administraion committees to discuss the medical school's operation because of many differences between nursing and medical organization. 4) Weakness of the leadership and the student activities in nursing student : The nursing student involvement is usually passive because of the difference of curriculum, less number than medical students and the difference between 4-year and 6-year education program. 5) There is the obscurity of the relationship between department of nursing and other departments in whole university. 2. Problems in nursing itself 1) We need to reconstruct nursing discipline. We must change from the disease centered model to health centered model and life cycle centered model so that we can be distinguished from medicine. We also must change from hospital centered nursing to all population centered nursing, 2) The improvement of curriculum ; When the independent framework of nursing discipline become established, we need to improve the curriculum. 3) The education of clinical practice ; Most nursing school programs are divided into professors who are lecturing the theory and clinical teachers who are teaching the nursing technique in the clinic. So, what is needed in nursing discipline is that the professors have a dual position. In America, The professor is required to be a clinical specialist and to have his or her clinic so that the professor become a good role model, teach the clinical practice effectively, and give the student the practice field. 4) To extend fields of nursing : At first, the school nurse must become the school health educator, a real teacher. The nurse must establish and operate a childern's wellbeing center or nursery school, a disabled people's house or senile's wellbeing center, a mental health center, and a health promotion clinic for healthy people. 5) The name 'nursing department' need to be considered. When the focus is to be changed from the disease model to health improvement model, we take into consideration change 'nursing college', 'nursing department' and 'nursing profession' to 'health science college' or 'health wellbeing college'. 6) We must have highly qualified academic students. Each Nursing educational faculties must have the high qualified students through the development of nursing educational program and the increment of scholarship. The Korean Nurses Association and The Korean Clinical Nurses Association need to make an endeavor for the improvement of work condition and payment of clinical nurses of hospitals who consist of 70% of all nursing manpower. 3. Improvement Strategy 1) All nursing educational program must be changed 4-year program gradually. 2) Nursing department need to try to become nursing college. 3) We need to study many researches for improvement of the problem in nursing discipline and nursing education. We need more interdisciplinary researches, and we need to be granted for that research. 4) We need to have many seminars and workshops thoughout the whole country to expand a sense of nursing education. 5) Drawing up a policies plan for the nursing educational improvement : The Korean Nurses Association, The Korean Academic Nursing Association, Korea Nursing College and department President's Committee, and Korea Academic Society of Nursing Education must try for the development of nursing educational improvement and ask for government frame the policy to develop nursing education.

  • PDF

A study on the origination and Transmission of Yu in Northeast Asia. -from the 4th Century to the 8th Century- (동북(東北)아시아 유의 기원(起源)과 그 교류(交流)에 관(關)한 연구(硏究) -$4{\sim}8$세기(世紀)를 중심(中心)으로-)

  • Cho, Sun-Hee;Park, Kyung-Ja
    • Journal of the Korean Society of Costume
    • /
    • v.17
    • /
    • pp.29-43
    • /
    • 1991
  • Yu was a type of dress worn on the upper part of the body which was commonly used in Northeast Asia. It was originally used by the Northern race for the need of courtesy as well as protecting cold. It was believed that Yu in Northeast Asia, which was called Kaftan, was came from Scythai lived in North Eurasian land around the Black sea. Scythians were the first-formed horse-riding race in the world and their civilization influenced those of far Asiatic sector along the steppe route. As their power expanded, their costume culture transmitted to the East(China, Korea, Japan). The upper garment, Yu, was characterized by the left-sided collars, narrow sleeves belted at the waist to the length of the hip line and the tight trouser on the lower part, which we commonly called HoBok(胡服) style. 1. Yu in Northeast Asia was originated from the Eurasians, Scythian Culture. Being exchanged, active style costumes were widely used among Chinese, Koreans and Japanese throughout centuries' including $4{\sim}8$ century. 2. Chinese Yu had a style of wide-sleeves and right-sided collars. The traditional costumes of Han race are consisted of wide-sleeved Yu on the upper and long-skirt on the lower part of the body. Before the adoptation of HoBok during reign of King Jo Mooryung in 307. B.C., HoBok style had already found in the remains since the Sang period. There were various names among Yu during the Han period. Seup, Sean Eui, Kye, Kyu were one of the styles and several names were meant for collar and sleeves. During $4{\sim}8$ centuries, clothes of right-sided collar were found, superior to that of left-sided and narrow sleeves were widely used both the royal and the humble. Various styles of decoration were seen in Yu around neck, back and sleeves comparing other nations. 3. Yu, in Korea, was typical style of Northern-bound HoBok. Both men and women had similarity in Yu style, narrow sleeves, left-sided collar, belted at the waist and to the length of hip line. Influenced by Han race, in the $4th{\sim}8th$ centuries, dual system of collar was found. But we cannot see major change in Yu and finally was connected to the present. 4. The original design of the Japanese costumes was not similar to that of Northern nomadic hunting race, which was suitable for horse-riding activities. Owing to the climates along the island, we could see various conditions ranging from the cold and to the warm. Influenced by the climates, pulling over the neck(Pancho style) were major design in Japan. As Korea was advanced earlier than Japan, Korean landed Japanese territory showing clothes. So primitive costumes had changes in style. During the $4th{\sim}8th$ period. The Korean mode was found in Haniwa (which was built to make sacrifices to the dead King) and costumes in Jeong Chang Won. Among the costumes in Jeong Chang Won, we put 3 or more costumes to the category of Yu characterizing elements of Korea and Tang period. From the $4th{\sim}8th$ century, China, Korea, Japan fell into the same cultural category, Scythai. Styles in Yu among three nations, we saw little differences, basically along times. Originated from the West Asia, Yu was transmitted to the far East changing Chinese costumes, Koreans melted it into the traditional elements and then influenced Japan.

  • PDF

A Study on Practices and Improvement Factors of Financial Disclosures in early stages of IFRS Adoption - An Integrative Approach of Korean Cases: Embracing Views of Reporting Entities and Users of Financial Statements (IFRS 공시 실태 개선방안에 대한 소고 - 보고기업, 정보이용자 요인을 고려한 통합적 접근 -)

  • Kim, Hee-Suk
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
    • /
    • v.7 no.2
    • /
    • pp.113-127
    • /
    • 2012
  • From the end of 1st quarter of 2012, Korean mandatory firms had started releasing financial reports conforming to the K-IFRS(Korean adopted International Financial Reporting Standards). Major characteristics of IFRS, such as 'principles based' features, consolidated reporting, 'fair value' measurement, increased pressure for non-financial disclosures have resulted in brief and various disclosure practices regarding the main body of each statements and vast amount of note description requirements. Meanwhile, a host of previous studies on IFRS disclosures have incorporated regulatory and/or 'compete information' perspectives, mainly focusing on suggesting further enforcement of strengthened requirements and providing guidelines for specific treatments. Thus, as an extension of prior findings and suggestions this study had explored to conduct an integrative approach embracing views of the reporting entities and the users of financial information. In spite of all the state-driven efforts for faithful representation and comparability of corporate financial reports, an overhaul of disclosure practices of fiscal year 2010 and 2011 had revealed numerous cases of insufficiency and discordance in terms of mandatory norms and market expectations. As to the causes of such shortcomings, this study identified several factors from the corporate side and the users of the information; some inherent aspects of IFRS, industry/corporate-specific context, expenditures related to internalizing IFRS system, reduced time frame for presentation. lack of clarity and details to meet the quality of information - understandability, comparability etc. - commonly requested by the user group. In order to improve current disclosure practices, dual approach had been suggested; Firstly, to encourage and facilitate implementation, (1) further segmentation and differentiation of mandates among companies, (2) redefining the scope and depth of note descriptions, (3) diversification and coordination of reporting periods, (4) providing support for equipping disclosure systems and granting incentives for best practices had been discussed. Secondly, as for the hard measures, (5) regularizing active involvement of corporate and user group delegations in the establishment and amendment process of K-IFRS (6) enforcing detailed and standardized disclosure on reporting entities had been recommended.

  • PDF

A Study on the Landscape Interpretation of Songge Byeoleop(Korean Villa) Garden at Jogyedong, Mt. Bukhansan near Seoul for the Restoration (북한산 조계동 송계별업(松溪別業) 정원 복원을 위한 경관해석)

  • Rho, Jae-Hyun;Song, Suk-Ho;Jo, Jang-Bin;Sim, Woo-Kyung
    • Journal of the Korean Institute of Traditional Landscape Architecture
    • /
    • v.36 no.4
    • /
    • pp.1-17
    • /
    • 2018
  • This study was conducted to interpret the landscape of Songge Byeoleop(Korean villa) garden at Jogyedong, Bukhansan near Seoul which was built in the mid 17C. to restore through the literature reviews and field surveys. The results were as follows; Songge Byeoleop garden was a royal villa, constructed at King Injo24(1646) of Joseon dynasty by prince Inpyeong(麟坪大君), Lee, Yo(李?, 1622~1658), the third son of King Injo who was a brother of King Hyojong. It was a royal villa, Seokyang-lu under Mt. Taracsan of Gyendeokbang, about 7km away in the straight line from main building. It was considered that the building system was a very gorgeous with timber coloring because of owner's special situation who was called the great prince. The place of Songge Byeoleop identity and key landscape of the place were consisted with Gucheon waterfall and the sound of the water with multi-layered waterfall which might be comparable to the waterfall of Yeosan in China. After the destruction of the building, the place was used for the royal tomb quarry, but there was a mark stone for forbidden quarry. The Inner part of Songge Beoleop, centered with Jogedongcheon, Chogye-dong, composted beautifully with the natural sceneries of Gucheon waterfall, Handam and Changbeok, and artificial structures, such as Bihong-bridge, Boheogak, Yeonghyudang and Gyedang. In addition, the existing Chinese characters, 'Songge Beoleop' and 'Gucheoneunpog' carved in the rocks are literary languages and place markings symbolizing with the contrast of the different forests and territories. They gave the names of scenery to the rock and gave meaning to them. Particularly, Gucheon waterfall which served as a visual terminal point, is a cascade type with multi-staged waterfall. and the lower part shows the topographical characteristics of the Horse Bowl-shaped jointed with port-holes. On the other hand, the outer part is divided into the spaces for the main entrance gate, a hanging bridge character, a bridge connecting the inside and the outside, and Yeonghyudang part for the purpose of living. Also in the Boheogak area, dual view frame structures are made to allow the view of the four sides including the width and the perimeter of the villa. In addition, at the view point in Bihong-bridge, the Gucheon water fall divides between the sacred and profane, and crosses the Bihong-bridge and climbs to the subterranean level.

Effects of Column Diameter on the Holdups of Bubble, Wake and Continuous Liquid Phase in Bubble Columns with Viscous Liquid Medium (점성액체 기포탑에서 탑의 직경이 기포, wake 및 연속액상 체류량에 미치는 영향)

  • Lim, Dae Ho;Jang, Ji Hwa;Kang, Yong;Jun, Ki Won
    • Korean Chemical Engineering Research
    • /
    • v.49 no.5
    • /
    • pp.582-587
    • /
    • 2011
  • Holdup characteristics of bubble, wake and continuous liquid phases were investigated in bubble columns with viscous liquid media. Effects of column diameter(0.051, 0.076, 0.102 and 0.152 m ID), gas velocity($U_G$=0.02~0.16 m/s) and liquid viscosity(${\mu}_L$=0.001~0.050 $Pa{\cdot}s$) of continuous liquid media on the holdups of bubble, wake and continuous liquid phases were discussed. The three phase such as bubble, wake and continuous liquid phases were classified successfully by adapting the dual electrical resistivity probe method. Compressed filtered air and water or aqueous solutions of CMC(Carboxy Methyl Cellulose) were used as a gas and a liquid phase, respectively. To detect the wake as well as bubble phases in the bubble column continuously, a data acquisition system(DT 2805 Lab Card) with personal computer was used. The analog signals obtained from the probe circuit were processed to produce the digital data, from which the wake phase was detected behind the multi-bubbles as well as single bubbles rising in the bubble columns. The holdup of bubble and wake phases decreased but that of continuous liquid media increased, with an increase in the column diameter or liquid viscosity. However, the holdup of bubble and wake phases increased but that of continuous media decreased with an increase in the gas velocity. The holdup ratio of wake to wake to bubble phase decreased with an increase in the column diameter or gas velocity, however, increased with an increase in the viscosity of con-tinuous liquid media. The holdups of bubble, wake and continuous liquid media could be correlated in terms of operating variables within this experimental conditions as: ${\varepsilon}_B=0.043D^{-0.18}U_G^{0.56}{\mu}_L^{-0.13}$, ${\varepsilon}_W=0.003D^{-0.85}U_G^{0.46}{\mu}_L^{-0.10}$, ${\varepsilon}_C=1.179D^{0.09}U_G^{-0.13}{\mu}_L^{0.04}$.

The costume culture of China is as old and varied as her long history (중국 소수민족의 복식 연구(1))

  • 박춘순
    • Journal of the Korean Society of Costume
    • /
    • v.26
    • /
    • pp.175-206
    • /
    • 1995
  • The costume culture of China is as old and varied as her long history. As China is a multiracial nation and consists of fifty-six min-ority races including Han race, there are not only fifty-six different costumes in China but each races' costume habit is very different. Therefore, Chinese penninsula can be considered an enor-mous exhibition center of the costumes. This study undertook on the assumption that the costumes' mainstream of Korea and east-northern Asia as well as that of China could be examined by investigating the minority races' costumes in the east-and west-northern areas of China. The process of evolution of the costume of a particular people, country or area is subject not only to constraints related to geography such as climate, topography or local products but is also affected by numorous environmental influences including cultural, economic, social and even pol-itical ones in terms of the selection of material, styling, color and standard of tailoring. In other words, things like philosophy of life, religious be-lief, aesthetic outlook, moral code, class system, degree of affluence, and cultural exchange will all be reflected directly or indirectly by features of a people's or country's style costume. Of course, there are several factors affecting to the style of costume of the minority people in China. However, the only three factors-geo-graphical and environmental, production method, and religious belef-will be touched in this study. First of all, the geograghical and eenviron-mental factor would be the decisive one because the costume should be designed to overcome the constraints of climate and geographical environ-ments. Accordingly, each race has an unique style of costume. The costume of the minority races in the northern parts are loose and wide, and made of warm furs. For instance, Mongolian robe has the quality of anti-wind, anti-cold and warmness, and the width of a sleeve is narrow and long. Secondly, the costume style can be said to be limited by the production pattern, when the geo-graphical environment was affected to decide the costume style, the production pattern was together affected to it . In case of Mongolian robe, they should satisfy the dual condition as the practical function. One is the condition that they should be fitted to the climate, and the other is the condition that they should be suit-able to the nomadic life. Mongolian robes are suitable to the nomadic peoples because they are designed for not only overcoming the cold wind and weather but being used as the bedquit at night. The costumes of Hoche people was made of the skin of the fish and wild animals because of their main means of living being fishing and hunting. Accordingly, their costumes are dur-able, warm and water-proof. Finally, the style of the costume is affected by the religious belief. In other words, the pattern in fashion is closely related with the religious be-lief or ancestor worship and nature worship. Ac-cordingly, the symbols of these worship are often emerged in the decoration of the costume. The design of costume of the people in the northern areas of China is very simple. It is related with their monotheism. On the other hand, the costumes of twen쇼 minority races in the east-northern parts of China can be devided into three racial groups such as the long robes of Man people and Mongols, Tunics of the peoples in the west-northern areas, and the pants and jackets of Hoche people. The minorority races all has not only the unique costume habit but their costumes are also related with their living style and production means.

  • PDF

학교도서관 발전의 저해요인에 관한 실증적 고찰 -일학교장의 학교도서관에대한 인식을 중심으로-

  • 김남석;김정소
    • Journal of Korean Library and Information Science Society
    • /
    • v.7
    • /
    • pp.1-55
    • /
    • 1980
  • It has been observed that the purpose of education is poorly coordinated with the school library. Consequently a healthy growth of the library has been very rare, and educational process has been rather inefficient. Therefore this study attempts to define the role of a school library and the necessasity of its growth, examine principals' concepts of the library, find out the adverse causes for its growth, and make some suggestions to rectify them. A questionnaire was designed to get information on the principals' conceptions about the nature and the role of a school library, a librarian, and adverse causes for the growth of the library. This study is largely based on the analysis of this questionnaire. The results of this study may be summarized as. follows: 1) The school library is not generally considered as the center of educational activities. It is rather variously regarded as a subsidiary organization for education, a place where reading materials are offered, a place where books are kept, or a reading room. 2) This was largely due to the misconceptions of the principals as to the true nature and the role of the school library. 3) The degrees of their misconceptions varied depending on the amount of their exposure to the library science. Those principals who studied library science more hours had better understanding of the library. 4) Although the principals showed rather much concern for the library, the school library was not up to the expectation largely due to their misconception of it. 5) Most of the principals felt that they needed more knowledge on library science to carry out their job. This feeling was stronger for those who spent more hours in a library science course. 6) Most of the principals wanted to offer a position for a dual function: a librarian and a teacher. This was largely due to their lack of knowledge as to the duties of a librarian-which were considered as secondary to the duties of a teacher. 7) The majority of the principals thought the librarians were not paid well enough, but some of the principals o n.0, pposed their pay raise. The former generally took more courses in library science than the latter. 8) Many principals agreed that the adverse causes for the growth of the school library originated from the regional or governmental school authorities. This seemed to indicate that the legal requirements for the library were inadequate and that there was no administrative organization to take care of the library. 9) Most of the principals considered the insufficient funds as the major reason for the present poor condition of the library. But considering the fact that some libraries are better equi n.0, pped that others, financial matter cannot be the deciding factor. It rather seemed that there is some serious problems in the current educational system. For further studies in this field and for the libraries to function properly, the following suggestions are made here: 1) The major adverse cause for the healthy growth of the school library was found in the misconceptions on the school library by the principals, and these misconceptions were largely due to their lack of knowledge. Therefore they should be given more o n.0, pportunities to take courses in library science. 2) The librarian should not be overburdened with other duties than what his job duly calls for, and they should be properly compensated for their own job. They should also be encouraged to grow as librarians. 3) Education itself should be improved so that the library becomes the center of learning. 4) An administrative department should be created to oversee the school libraries, and legal measures should be enacted for better school libraries. 5) Financial su n.0, pport should be provided for a period of time in order to upgrade the school library to a certain level. Finally it is strongly felt that more detailed and inclusive studies in this field should be carried on and further experimental studies should be done.

  • PDF

EFFICIENCY OF ENERGY TRANSFER BY A POPULATION OF THE FARMED PACIFIC OYSTER, CRASSOSTREA GIGAS IN GEOJE-HANSAN BAY (거제${\cdot}$한산만 양식굴 Crassostrea gigas의 에너지 전환 효율)

  • KIM Yong Sool
    • Korean Journal of Fisheries and Aquatic Sciences
    • /
    • v.13 no.4
    • /
    • pp.179-183
    • /
    • 1980
  • The efficiency of energy transfer by a population of the farmed pacific oyster, Crassostrea gigas was studied during culture period of 10 months July 1979-April 1980, in Geoje-Hansan Bay near Chungmu City. Energy use by the farmed oyster population was calculated from estimates of half-a-month unit age specific natural mortality rate and data on growth, gonad output, shell organic matter production and respiration. Total mortality during the culture period was estimated approximate $36\%$ from data on survivor individual number per cluster. Growth may be dual consisted of a curved line during the first half culture period (July-November) and a linear line in the later half period (December-April). The first half growth was approximated by the von Bertalanffy growth model; shell height, $SH=6.33\;(1-e^{0.2421(t+0.54)})$, where t is age in half-a-month unit. In the later half growth period shell height was related to t by SH=4.44+0.14t. Dry meat weight (DW) was related to shell height by log $DW=-2.2907+2.589{\cdot}log\;SH,\;(2, and/or log $DW=-5.8153+7.208{\cdot}log\;SH,\;(5. Size specific gonad output (G) as calculated by condition index of before and after the spawning season, was related to shell height by $G=0.0145+(3.95\times10^{-3}{\times}SH^{2.9861})$. Shell organic matter production (SO) was related to shell height by log $SO=-3.1884+2.527{\cdot}1og\;SH$. Size and temperature specific respiration rate (R) as determined in biotron system with controlled temperature, was related to dry meat weight and temperature (T) by log $R=(0.386T-0.5381)+(0.6409-0.0083T){\cdot}log\;DW$. The energy used in metabolism was calculated from size, temperature specific respiration and data on body composition. The calorie contents of oyster meat were estimated by bomb calorimetry based on nitrogen correction. The assimilation efficiency of the oyster estimated directly by a insoluble crude silicate method gave $55.5\%$. From the information presently available by other workers, the assimilation efficiency ranges between $40\%\;and\;70\%$. Twenty seven point four percent of the filtered food material expressed by energy value for oyster population was estimated to have been rejected as pseudofaeces : $17.2\%$ was passed as faeces; $35.04\%$ was respired and lost as heat; $0.38\%$ was bounded up in shell organics; $2.74\%$ was released as gonad output, $2.06\%$ was fell as meat reducing by mortality. The remaining $15.28\%$ was used as meat production. The net efficiency of energy transfer from assimilation to meat production (yield/assimilation) of a farm population of the oyster was estimated to be $28\%$ during culture period July 1979-April 1980. The gross efficiency of energy transfer from ingestion to meat production (yield/food filtered) is probably between $11\%\;and\;20\%$.

  • PDF

Effect of $Ca^{2+}$ and $Ca^{2+}-antagonists$ on the Spontaneous Contractions and Electrical Activities of Guinea-pig Stomach (기니피그 위 평활근의 자발적 수축과 전기적 활동에 대한 $Ca^{2+}$$Ca^{2+}$-길항제 영향)

  • Rhie, Sang-Ho;Kim, Ki-Whan
    • The Korean Journal of Physiology
    • /
    • v.21 no.2
    • /
    • pp.241-257
    • /
    • 1987
  • The effects of external $Ca^{2+}$ and $Ca^{2+}-antagonists$ on the spontaneous contractions and electrical activities were investigated in guinea-pig stomach in order to clarify the mechanism for the generation of slow waves. Electrical responses of circular smooth muscle cells were recorded using glass capillary microelectrodes filled with 3 M KCl. All experiments were performed in tris-buffered Tyrode solution which was aerated with 100% $O_2$ and kept at $35^{\circ}C$. The results obtained were as follows: 1) The amplitude of spontaneous contractions was maximal at around 2-4 mM $Ca^{2+}$, whereas their frequency was inversely related with external $Ca^{2+}$ within the range of 0.5 to 16 mM $Ca^{2+}$. 2) Verapamil suppressed the amplitude of spontaneous contraction in a dose-dependent manner, while the frequency of spontaneous contractions was almost not changed over the whole concentration of verapamil $(0.01{\sim}5\;mg/l)$. 3) Manganese increased both the amplitude and the frequency of spontaneous contractions dose-dependently in low $Mn^{2+}$ (below 0.05 mM $Mn^{2+}$), while their amplitude and frequency were decreased in high $Mn^{2+}$ (above 0.1 mM $Mn^{2+}$). 4) The ampltude and maximum rate of rise of slow waves were incrased in high $Ca^{2+}$ solution. In $Ca^{2+}-free$ solution, the spontaneous contractions recorded simultaneously with slow waves ceased and tonic contraction ($Ca^{2+}-free$ contracture) was developed in parallel with membrane depolarization and the disappearance of slow waves. 5) Verapamil (1 mg/1) decreased the amplitude and maximum rate of rise of slow waves and it depolarized the membrane by about 6 mV, whereas the frequency of slow waves was not affected by verapamil. 6) Manganese showed different characteristic effects between low and high $Mn^{2+}$ on the slow waves: In low $Mn^{2+}$ (0.05 mM $Mn^{2+}$), the initial rapid increases and the subsequent gradual decreases in three parameters of slow waves (amplitude, rate of rise, and frequency of slow waves) till a new steady state were observed. However, in high $Mn^{2+}$ (0.5 mM $Mn^{2+}$) slow waves disappeared and membrane was depolarized. From the above results, the following conclusions could be made: 1) $Ca^{2+}$ is necessary for a generation of the slow waves, even though it is small amount. 2) Verapamil suppresses the spontaneous contractions of gastric antral strip by the decreases in amplitude and maximum rate of rise of slow waves, while this drug does not block the $Ca^{2+}-channel$ involved in the generation of slow waves. 3) Manganese has dual actions on the $Ca^{2+}-channels$; the $Ca^{2+}-channel$ involved in the generation of slow waves (or Na-Ca exchange system) or the channel for the generation of spike potentials are stimulated by a low concentration of $Mn^{2+}$, while both the $Ca^{2+}$. Channels are blocked by high concentration of $Mn^{2+}$.

  • PDF