The Effects of Cardioplegic Solutions on the Energy Source of the Guinea Pig Heart

박혜수,박소라,이영호,김인숙,서창국,강복순,Park, Hye-Soo,Park, So-Ra,Lee, Young-Ho,Kim, In-Sook,Suh, Chang-Kook,Kang, Bok-Soon The Korean Physiological Society 1989 대한생리학회지 Vol.23 No.1

The changes in adenosine triphosphate (ATP), creatine phosphate (CP) and lactic acid (LA) contents of guinea pig hearts were studied during the cardioplegia and recovery phase. 1) ATP and CP contents in cardiac ventricular tissue were decreased during the cardioplegia, regardless of $Ca^{2+}$ concentration in the cardioplegic solutions, and CP contents were recovered with the reperfusion of normal Tyrode solution faster than those of ATP. And there were no significant differences in the recovery of CP contents with different concentration of $Ca^{2+}$ in the cardioplegic solutions tested, while the recovery of ATP contents was faster with 15 mM $K^{+}$, 0.1 mM $Ca^{2+}$ cardioplegic solutions. 2) LA contents were increased during the cardioplegia and decreased with the reperfusion of normal Tyrode solution. 3) The more recovery time (up to 3 hrs), the more CP contents were recovered with the reperfusion of normal Tyrode solution faster than those of ATP. And LA contents were decreased as the duration of recovery time. These results suggest that $Ca^{2+}$ and $K^{+}$ concentration in the cardioplegic solution is one of the major factors influencing the recovery of cardiac tissue from the cardioplegia. 심근정지용액의 조성이 심근정지 및 심근정지 후 회복기의 에너지원에 미치는 영향을 조사하기 위해 guinea pig 심실 균질액에서 adenosine triphosphate (ATP), creatine phosphate (CP) 및 lactic acid (LA)의 변화를 관찰하여 다음과 같은 결과를 얻었다. 1) ATP 및 CP 양은 심근정지동안은 감소하고 회복기에는 다시 증가하였으며, 심근정지 후 정상용액으로 30분간 회복시켰을 때에는 ATP 양의 회복이 CP에 비해 느린것을 알 수 있었다. 2) LA 양은 심근정지동안은 증가하고 회복기에는 다시 감소하였다. 3) 심근정지 후 회복시간을 길게할수록 ATP 및 CP 양의 회복은 증가하였으며 CP 양이 더 많이 회복되었다. 4) LA 양도 회복시간을 길게할수록 감소하였다. 이상의 결과를 종합하여 볼 때, 심근정지용액의 $Ca^{2+}$ 및 $K^{+}$ 농도는 심근정지후 회복시 심근세포의 에너지원인 ATP, CP 및 lactic acid 양에 영향을 미친다고 생각된다. 이 연구 결과를 토대로 심근세포내 $Na^{+}$과 $H^{+}$ 활성도 변화 및 심근세포의 산증(acidosis)에 관한 연구를 첨가하면 심근정지시의 심근보호기전을 규명하는데 도움이 될 것으로 생각된다.

이승만과 하와이 감리교회와의 관계

박혜수(Hae-Soo Park) 연세대학교 신과대학(연합신학대학원) 2012 신학논단 Vol.68 No.-

Syngman Rhee, upon turning 20 years old in April 1895, enrolled at Pai Chai College established by American Methodist evangelist Henry G. Appenzeller and studied English and modern science. This was Syngman Rhee’s first encounter with Methodist Church. After graduating Pai Chai College, Syngman Rhee was implicated in attempts of coup’ de ta with Park Young Hyo and was arrested in January 9, 1899, living a prison life at Hansung Prison for five years and seven months, until August 1904. In prison, severe pain and hardships made him pray and turn to Christianity. Regular visits by Presbyterian and Methodist missionaries made Syngman Rhee mature as a Christian, along with his conversion. He evangelized and taught gospel to a number of people by constructing prison library and school in prison. Furthermore, since his conversion in jail, he started writing and researching on Christianity through reading Christianity related books in full-fledged effort. In November 1903, his thesis ?his first church-related dissertation written while in prison, titled “Church Strategy,” was carried in the Methodist theology magazine, Christian Monthly. In August 1904, immediately prior to his release from prison, he presented his thesis, “The Toils of the Korean Christian Brethren” ? also carried in Christian Monthly ? thereby continuing his efforts to spread the gospel and the salvation to one’s family and country. Upon obtaining his doctorate degree from Princeton University on July 18, 1910, Syngman Rhee returned to South Korea on October 10 to act as a manager of Seoul YMCA, staying in Korea for a year and a half. During Korean Lay Electoral Conference held in Seoul on March 9, 1912, he was elected as a representative of Korean layman for the Quadrennial General Conference of the Methodist Episcopal Church. Following his participation at the Quadrennial General Conference, on 3 February 1913, Syngman Rhee made his second visit to Hawaii. Immediately after Rhee arrived in Hawaii, from 27 February to 2 March, he supervised a training organization for Bible study and Methodist doctrine for Korean Methodist religious servers and leaders who participated in the Conference from Honolulu’s First Methodist Church. This created an opportunity for Rhee to carve out his reputation as a model religious worker for the Methodist Church in Hawaii. On 25 August 1913, Syngman Rhee took office as the principal of the Korean Boarding School for Boys, a school operated by the American Methodist Episcopal Mission. Upon Syngman Rhee’s assumption of the principal’s post, the school changed its name to the Korean Central School and, through the innovative operation of the school, in six months the enrollment skyrocketed from 36 to 120 students. Clashes with the Methodist Episcopal Mission’s education policies, however, resulted in the school’s leaving the Methodist Episcopal Mission, and Rhee went on to independently establish a Korean Christian Institute. In essence, while the Americans strove to Americanize the Koreans by completely assimilating them into Hawaiian society, Rhee on the other hand wanted to train and prepare the Koreans in the event that they would have to contribute to Korea’s exercise to recover its national sovereignty. As conflict between Rhee and the Methodist Episcopal Mission surfaced, Rhee left the Methodist Church and established independent Korean Christian Church. Although he left the Methodist Church in Hawaii to achieve his goal of establishing a church owned and asserted by Koreans, Rhee never left Methodist Church. Whether he acted on his own or under the auspices of the Methodist Church, he was forever a Methodist. Syngman Rhee, upon turning 20 years old in April 1895, enrolled at Pai Chai College established by American Methodist evangelist Henry G. Appenzeller and studied English and modern science. This was Syngman Rhee’s first encounter with Methodist Church. After graduating Pai Chai College, Syngman Rhee was implicated in attempts of coup’ de ta with Park Young Hyo and was arrested in January 9, 1899, living a prison life at Hansung Prison for five years and seven months, until August 1904. In prison, severe pain and hardships made him pray and turn to Christianity. Regular visits by Presbyterian and Methodist missionaries made Syngman Rhee mature as a Christian, along with his conversion. He evangelized and taught gospel to a number of people by constructing prison library and school in prison. Furthermore, since his conversion in jail, he started writing and researching on Christianity through reading Christianity related books in full-fledged effort. In November 1903, his thesis ?his first church-related dissertation written while in prison, titled “Church Strategy,” was carried in the Methodist theology magazine, Christian Monthly. In August 1904, immediately prior to his release from prison, he presented his thesis, “The Toils of the Korean Christian Brethren” ? also carried in Christian Monthly ? thereby continuing his efforts to spread the gospel and the salvation to one’s family and country. Upon obtaining his doctorate degree from Princeton University on July 18, 1910, Syngman Rhee returned to South Korea on October 10 to act as a manager of Seoul YMCA, staying in Korea for a year and a half. During Korean Lay Electoral Conference held in Seoul on March 9, 1912, he was elected as a representative of Korean layman for the Quadrennial General Conference of the Methodist Episcopal Church. Following his participation at the Quadrennial General Conference, on 3 February 1913, Syngman Rhee made his second visit to Hawaii. Immediately after Rhee arrived in Hawaii, from 27 February to 2 March, he supervised a training organization for Bible study and Methodist doctrine for Korean Methodist religious servers and leaders who participated in the Conference from Honolulu’s First Methodist Church. This created an opportunity for Rhee to carve out his reputation as a model religious worker for the Methodist Church in Hawaii. On 25 August 1913, Syngman Rhee took office as the principal of the Korean Boarding School for Boys, a school operated by the American Methodist Episcopal Mission. Upon Syngman Rhee’s assumption of the principal’s post, the school changed its name to the Korean Central School and, through the innovative operation of the school, in six months the enrollment skyrocketed from 36 to 120 students. Clashes with the Methodist Episcopal Mission’s education policies, however, resulted in the school’s leaving the Methodist Episcopal Mission, and Rhee went on to independently establish a Korean Christian Institute. In essence, while the Americans strove to Americanize the Koreans by completely assimilating them into Hawaiian society, Rhee on the other hand wanted to train and prepare the Koreans in the event that they would have to contribute to Korea’s exercise to recover its national sovereignty. As conflict between Rhee and the Methodist Episcopal Mission surfaced, Rhee left the Methodist Church and established independent Korean Christian Church. Although he left the Methodist Church in Hawaii to achieve his goal of establishing a church owned and asserted by Koreans, Rhee never left Methodist Church. Whether he acted on his own or under the auspices of the Methodist Church, he was forever a Methodist.

편의점 정제타입의 해열진통제 패키지디자인 연구

박혜수(Park, Hyesoo),이은실(Yi, Eunsil) 인제대학교 디자인연구소 2015 Journal of Integrated Design Research (JIDR) Vol.14 No.4

연구배경 : 최근 편의점 및 약국 외의 장소에서 안전상비 의약품이 판매되면서 소비자들은 의사의 처방이나 약사의 도움 없이 약품을 쉽고 빠르게 구입할 수 있으나 약국과 패키지의 차이가 없는 안전상비의약품으로 스스로 구입함으로써 부작용이나 오남용발생 가능성이 증가하는 문제점이 발생한다. 연구방법 : 안전상비의약품과 일반의약품의 차이점을 비교분석하고 소비자의 불편함 및 요구사항을 설문조사를 통해 분석하여 문제점을 도출한다. 해외 우수 의약품 패키지디자인을 사례를 바탕으로 도출된 문제점의 해결방안을 제시한다. 연구결과 : 의약품에서 필요한 요소로 브랜드 네임, 효능·효과, 용량·용법, 부작용 및 주의사항과 패키지디자인에 필요 요소들인 브랜드 네임, 색채, 타이포그래피, 일러스트레이션, 레이아웃으로 분류하고 문제점을 도출하여 그에 대한 해결방안을 제시하였다. 결론 : 편의점용 해열진통제 패키지디자인 개선을 통해 처방전이나 약사 없이 구매를 할 때에 어려움 없이 정보전달을 통해서 소비자들이 쉽고 빠르게 구매를 할 수 있고 구매율을 높여 조기 예방과 치료에 힘쓸 것이다. Background : Recently, patients can buy medicine at Convenience stores quickly and easily without doctor’s a prescription or help of pharmacists. But there is no difference between packages of pharmacy and CVS. It could have bad side effects from the misuse of a medication. Methods : In this study, it is inclined to improve package design for Tylenol conducting a survey and investigating the current situation. Result : The results indicated that there is not difference of adult, junior and children’s antipyretic-analgesics package design through the survey. On this account I tried to help patients who purchase medicine at CVS to emphasize information they want when they are getting medicine. Conclusion : Through improved package design when you buy antipyretic-analgesics without a prescription or a pharmacist at CVS without difficulty passing through the information, patients can make purchases quickly and easily also will keep studying to increase the buying for early prevention and treatment.

심근 정지 용액이 심근의 에너지원에 미치는 영향

박혜수(Park, Hye-Soo),박소라(Park, So-Ra),이영호(Lee, Young-Ho),김인숙(Kim, In-Sook),서창국(Suh, Chang-Kook),강복순(Kang, Bok-Soon) 대한생리학회 1989 대한생리학회지 Vol.23 No.1

심근정지용액의 조성이 심근정지 및 심근정지 후 회복기의 에너지원에 미치는 영향을 조사하기 위해 guinea pig 심실 균질액에서 adenosine triphosphate (ATP), creatine phosphate (CP) 및 lactic acid (LA)의 변화를 관찰하여 다음과 같은 결과를 얻었다. 1) ATP 및 CP 양은 심근정지동안은 감소하고 회복기에는 다시 증가하였으며, 심근정지 후 정상용액으로 30분간 회복시켰을 때에는 ATP 양의 회복이 CP에 비해 느린것을 알 수 있었다. 2) LA 양은 심근정지동안은 증가하고 회복기에는 다시 감소하였다. 3) 심근정지 후 회복시간을 길게할수록 ATP 및 CP 양의 회복은 증가하였으며 CP 양이 더 많이 회복되었다. 4) LA 양도 회복시간을 길게할수록 감소하였다. 이상의 결과를 종합하여 볼 때, 심근정지용액의 Ca²⁺ 및 K⁺ 농도는 심근정지후 회복시 심근세포의 에너지원인 ATP, CP 및 lactic acid 양에 영향을 미친다고 생각된다. 이 연구 결과를 토대로 심근세포내 Na⁺과 H⁺ 활성도 변화 및 심근세포의 산증(acidosis)에 관한 연구를 첨가하면 심근정지시의 심근보호기전을 규명하는데 도움이 될 것으로 생각된다. The changes in adenosine triphosphate (ATP), creatine phosphate (CP) and lactic acid (LA) contents of guinea pig hearts were studied during the cardioplegia and recovery phase. 1) ATP and CP contents in cardiac ventricular tissue were decreased during the cardioplegia, regardless of Ca²⁺ concentration in the cardioplegic solutions, and CP contents were recovered with the reperfusion of normal Tyrode solution faster than those of ATP. And there were no significant differences in the recovery of CP contents with different concentration of Ca²⁺ in the cardioplegic solutions tested, while the recovery of ATP contents was faster with 15 mM K⁺, 0.1 mM Ca²⁺ cardioplegic solutions. 2) LA contents were increased during the cardioplegia and decreased with the reperfusion of normal Tyrode solution. 3) The more recovery time (up to 3 hrs), the more CP contents were recovered with the reperfusion of normal Tyrode solution faster than those of ATP. And LA contents were decreased as the duration of recovery time. These results suggest that Ca²⁺ and K⁺ concentration in the cardioplegic solution is one of the major factors influencing the recovery of cardiac tissue from the cardioplegia.

지속가능한 발전을 위한 국가별 동향분석 및 통합혁신정책 제안

박혜수(Park Hye-Soo),김지응(Kim Ji-Eung),지성현(Ji Sung-Hyun) 지속가능과학회 2011 STSS지속가능과학회 학술대회 Vol.2011 No.6

저탄소 녹색성장은 국가 에너지 안보와 신성장동력에 있어서 국가 경제발전의 새로운 패러다임이다. 그러나 우리나라는 1990년과 2005년 사이 온실가스 배출이 2배 증가할 정도로 탄소 배출량이 급격히 증가해왔다. 본 연구에서는 OECD 회원국 중 우리나라와 산업구조 및 경제 성장 발전 유사 국가인 체코와 이탈리아의 온실가스 배출 감축 현황과 에너지 동향을 비교 분석하여 국가별 정책적 주요 이슈를 도출해 내었다. 그 결과 선진국으로서 입지를 확고히 다지고 녹색성장과 함께하는 경제 역량을 발달시키기 위해서 탄소 배출 감축에 동참하는 동시에 지속가능한 에너지 및 녹색기술에 대한 체계적 목표 설정 및 통합 정책적 국가 노력이 필요한 것으로 사료되었다. 따라서 본 논문에서는 각 국가별 동향 분석을 통하여 지속가능한 발전을 위한 혁신적인 통합 정책을 제안하고자 한다.

통신사업자 투자지출액 변화에 따른 투자효과 실증분석 연구

박혜수(Hye Su Park),지성현(Sung Hyun Ji),박선영(Sun-Young Park) 한국데이타베이스학회 2013 Journal of information technology applications & m Vol.20 No.4

Domestic telecommunication companies have increased in marketing expenditures and capital investments in their plants and equipments. Their expectation for their investment sometimes results in the shrinking of their ARPUs(average revenues per user) as well as decreasing of net profits. Those financial efforts have not always been positive relation with their ARPUs. Since western and european telecommunication industryrecently have similar situation with our market where their mobile and network users have been saturated so that no more increased users are estimated. Therefore, this paper aims for first to explore methods maximizing the investments efficiency for the telecommunication company so that we choose bechmarked telecommmunication companies to explore their investment managing situation with resepct to their marketing and capital expenditure. Secondly this paper tried to suggest several public policy guidelines for domestic telecommunication industry. Total seventeen foreign telecommunication companies were selected and data set through official IR as well as AR were chosen. Curvilinear logarithmic regression analysis were tested to obtain elasticities as well as marginal effects. As a result, overspending on the marketing investment showed more negative indicators to their revenues, on the other hand, more investment in the Capex such as network infrastructures and other service facilities were more likely related to positive revenues.

Stellar Detector를 적용한 저선량 흉부 CT의 최적 프로토콜에 관한 연구

박혜수(Hye Su Park),이기백(Ki Baek Lee),구현정(Hyun Jung Ko) 대한전산화단층기술학회 2015 대한CT영상기술학회지 Vol.17 No.2

목적 : 조기 발견이 중요한 폐암의 경우 일반 흉부 X선 검사의 한계로 인해 Low dose chest CT가 권장되고 있다. 고화질 영상 획득으로 신뢰성이 높으나 여전히 다른 영상 촬영법에 비해 환자 피폭에 대한 risk를 가지고 있다. 이에 적은 선량으로 고화질의 영상을 획득하기 위해 최근에는 검출기 성능을 향상시키고자 개발된 Stellar detector가 있다. 본 논문은 Stellar detector를 기존 검출기와 비교하여 성능을 평가하고 저선량 흉부 CT의 최적 프로토콜을 찾고자 한다. 대상 및 방법 : Stellar detector 기술을 반영한 128채널의 Somatom Definition Edge (Siemens, Erlangen, Germany)와 이전 모델인 128채널의 Somatom Definition AS+ (Siemens, Erlangen, Ge rmany)를 비교평가 하였다. 검사 조건으로는 관전압은 100kVp, 120kVp, 140kVp를 사용하고 관전류는 10mAs에서 50mA까지 5mAs씩 증가시켜 적용하였다. 그 외에 인자들은 Low-dose Chest CT 프로토콜과 동일하게 진행하였다. 정량적 평가를 위해 영상의 Noise와 CNR을 분석하였다. 정성적 평가는 두 가지 기준을 채택하였다. 인체 흉부 팬텀 (Lung Chest Phantom; FLUKE BIOMECAL, RS-330, CLEVELAND)을 이용한 저선량 흉부 CT 판독 소견과 AAPM performance phantom(model 76-4104130, US)의 High spatial contrast resolution 블록에 발견되는 양자잡음 (Quantom noise, 양자반점) 발생 정도를 평가하였다. 결과 : 정량적 분석에서 Edge가 AS+에 비해 모든 조건 하의 CNR 값이 높았다. 통계적으로 p〈0.05가 성립되어 데이터의 차이를 확인하였다. 정성적 평가에서는 Edge의 경우 100kVp/45mAs, 120kVp/20mAs, 140kVp/20mAs가, AS+의 경우 100kVp/50mAs, 120kVp/25mAs, 140kVp/20mAs가 선량측면까지 고려하여 높은 점수를 받았다. 두 번째 정성적 평가에서 Edge는 100kVp/20mAs, 120kVp/15mAs까지 다수의 양자잡음이 발생하였고 AS+는 100kVp/25mAs, 120kVp/20mAs, 140kVp/10mAs에서 발생하였다. 결론 : 종합적인 분석에 따르면 최적의 Low-dose Chest CT 프로토콜은 Edge장비에서는 120/20mAs, AS는 120/25mAs가 적합하다고 할 수 있다. 기존 검출기에 비해 약 12%의 CNR 증가율과 약 51%의 DLP 감소율을 보여주었다. 이를 통해 Stellar detector가 적은 선량에서도 상대적으로 고화질의 영상을 구현하고 우수한 성능을 가짐을 확인 할 수 있었다. Purpose : The state-of-the-art “Stellar detector” has been developed to improve detector performance for acquisition of high quality images with reduced radiation dose. The purpose of this study was to compare the performance between Stellar and the conventional detectors, and to find out the optimal low-dose chest CT protocol. Materials and Methods : 128-MDCT with newly built-in stellar detector, SOMATOM Definition Edge (Siemens, Erlangen, Germany) and 128-MDCT with conventional detector, SOMATOM Definition AS+ (Siemens, Erlangen, Germany) were used in this study. Scan settings were as follows: tube voltage of 100, 120, and 140 kVp, and tube current from 1 Oto 50 mAs in 5-mAs increment. Other parameters were the same as the standard low-dose chest CT protocol. Noise, CNR were analyzed for quantitative evaluation. For qualitative evaluation, two methods were used; radiologist’s interpretation of low-dose chest CT images of Lung Chest Phantom (FLUKE BIOMECAL, RS-330, CLEVELAND), and quantom noise appeared on the high spatial contrast resolution module of AAPM phantom. Result : In quantitative evaluation, CNR value of SOMATOM Definition Edge was higher than SOMATOM Definition AS+ under all scan settings. P-value was below 0.05 in Paired t-test. So It showed a stastically significant difference. First qualitative evaluation was assessed the image using the following 5-point score. The results of high quality image are as follows: 100kVp/45mAs, 120kVp/20mAs, 140kVp/20mA in SOMATOM Definition Edge and 100kVp/50mAs, 120kVp/25mAs, 140kVp/20mAs in SOMATOM Definition AS+. The results of second evaluation are as follows: we can find many quantum noise at 100kVp/20mAs, 120kVp/15mAs in SOMATOM Definition Edge and 100kVp/25mAs, 120kVp/20mAs, 140kVp/10mAs in SOMATOM Definition AS+. Conclusion : The optimal protocol for low-dose chest CT was found to be 120 kV/20 mAs and 120 kV/25 mAs for SOMATOM Definition Edge and AS+ scanners, respectively. It can provide 12% increase of CNR and 51% decrease of radiation dose. Stellar detector can provide high quality images with relatively lower radiation dose compared to the conventional detectors.

IS-95 CDMA 기지국용 스마트 안테나 시스템 성능분석

박혜수(Hyesu Park),박수미(Soomee Park),이지연(Jiyeoun Lee),최승원(Seungwon Choi) 한국통신학회 2000 한국통신학회 학술대회논문집 Vol.2000 No.11

한국인 관상동맥 질환에서 Chlamydia Pneumoniae 감염의 원인적 연관성에 관한 환자-대조군 연구

박혜수 ( Park Hye Su ),이지윤 ( Lee Ji Yun ),민원기 ( Min Won Gi ),박혜순 ( Park Hye Sun ),김영식 ( Kim Yeong Sig ) 한국지질동맥경화학회(구 한국지질학회) 2002 韓國脂質學會誌 Vol.12 No.4

Objective: Although there are some reports of other countries that chronic infection of Chlamydia pneumoniae (C. pneumoniae) induces atherosclerosis, it is still controversial. Therefore, we investigated serological study using ELISA for detection of C. p

성주기에 따른 자궁근 수축력의 변화에 관한 연구 : 성홀몬 및 약물들의 영향

김인교,박혜수,구본숙,이익호,Kim, In-Kyo,Park, Hye-Soo,Koo, Bon-Sook,Lee, Ek-Ho 대한생리학회 1987 대한생리학회지 Vol.21 No.1

It has been well known that estrogens stimulate the uterine contractility and progestins inhibit it. Then, one may expect that the uterine contractility and sensitivities to oxytocin (OT) and prostaglandin $F_{2{\alpha}}\;(PGF_{2{\alpha}})$ would be different among the estrus cycle. These hypotheses were tested using the mature female rat. Spontaneous isometric contractions of isolated uterine strips $(1{\times}0.3\;cm)$ from cyclic rats in various stages of the estrus cycle, bilateral ovarectomized rats and hypophysectomized rats were recorded in absence or presence with $estradiol-17{\beta}\;(E_2)$, progesterone $(P_4)$, OT and $PGF_{2{\alpha}}$. The results were summarized as follows: 1) The spontaneous uterine contractile force was the highest in the estrus rat and the lowest in the ovarectomized or the hypophysectomized rat. In the proestrus rat, the contractile frequency was the lowest (2.7 beats/10 min) and the contractile duration was the longest (70 sec). In the other groups, there were no any differencies in frequency (9 beats/10 min) and in duration (30 sec). 2) OT and $PGF_{2{\alpha}}$ stimulated the uterine contractility in all groups tested except in the hypophysectomized rat in which OT failed to stimulate the uterine contraction. $PGF_{2{\alpha}}$ was more effective in stimulating the uterine contraction than OT in all groups tested except in the estrus rat. OT-induced contraction was the highest in the estrus rat and $PGF_{2{\alpha}}-induced$ contraction was the lowest in the hypophysectomized rat. 3) Uterine contractilities were not changed by the in vitro treatments of $E_2$ or $P_4$ under the influence of endogenous steroids, however, $E_2$ and $P_4$ stimulated the uterine contraction in the ovarectomized rat in which endogenous steroids were almost abolished. 4) Increased uterine contraction by the treatment of OT was suppressed by in vitro $E_2$ or $P_4$ in the estrus rat, while it was potentiated by the $P_4$ in the proestrus rat. In other groups, exogenous $E_2$ or $P_4$ did not affect the OT-induced uterine contraction. 5) $PGF_{2{\alpha}}-induced$ uterine contraction was suppressed in the ovarectomized rat by $E_2$ and $P_4$, in the diestrus and proestrus rats by $P_4$ and in the hypophysectomized rat by $E_2$. In other groups, exogenous $E_2$ or $P_4$ was ineffective in altering the $PGF_{2{\alpha}}-induced$ uterine contraction. According to the above results, it may conclude that the mechanisms of the different uterine contractility and the different uterine sensitivity to OT or $PGF_{2{\alpha}}$ according to the estrus cycle are not explicable with only the serum concentrations of steroids, OT and $PGF_{2{\alpha}}$ but also other unknown factors.