Methylene Blue가 Acetylcholine및 Potassium Chloride에 의한 적출장관평활근수축에 미치는 영향

김인겸,최영환,정현주,김중영 慶北大學校 醫科大學 1996 慶北醫大誌 Vol.37 No.4

목적 : 본 실험은 guanylyl cyclase 억제제로 알려진 methylene blue(MB)가 acetylcholine(ACh) 및 potassium chloride (KCl)에 의하여 야기되는 적출장관수축에 미치는 영향을 관찰하였다. 대상 및 방법 : 생쥐의 적출장관을 Magus조내의 Tyrode 영양액중에 현수하고 MB 2×10 exp (-5)mM 존재하에 ACh(1mM) 또는 KCl(67mM)에 의하여 야기되는 장관평활근수축을 처음에 급격히야기되는 phasic수축과 이어 속발지속되는 tonic수축의 변화를 비교 하였다. 결과 : ACh및 KCl에 의한 phasic수축은 MB존재하에서 크게 영향을 받지 아니하나, tonic수축은 현저히 억제되었다. MB에 의한 tonic수축의 억제작용은 MB를 제거한 상태에서도 나타났는데, ACh에 비하여 KCl의 경우 그 억제현상이 더 지속되었다. 결론 : Guanylyl cyclase 억제제인 methylene blue 가 acetylcholine 및 potassium chloride 에 의하여 야기되는 칼슘유리와 관계되는 phasic 수축에 비하여, 칼슘유입과 관계되는 tonic수축이 현저히 억제하는 작용도 있는 것으로 생각된다. To examine effects of methylene blue(MB) on contraction of intestinal smooth muscle, acetylcholine (ACh)- and potassium chloride (KCl)-induced phasic and tonic contractions in the isolated duodenal strips from mice were observed in the presence of MB or not.Sixty minutes after Incubation with 2×10 exp (-2) mM of MB. 1 mM of ACh- and 67 mM of KCl-induced phasic contractions were not affected, but both drug-induced tonic contractions were inhibited. These results show that methylene blue inhibits ACh- or KCl-induced tonic contractions related to extracellar calcium influx rather than phasic contractions related to calcium release.

선천성 고혈압 흰쥐와 정상혈압 흰쥐의 혈관 평활근 세포의 성장 특성

정재군,정현주,김인겸,김중영 慶北大學校 醫科大學 1997 慶北醫大誌 Vol.38 No.2

목적 : 선천성 고혈압 흰쥐(SHR)와 정상 혈압 흰쥐(WKY)의 혈관 평활근 세포를 배양하여, 그 성장 특성을 조사하였다. 대상 및 방법 : SHR 및 WKY를 pentobarbital(50㎎/㎏)로 마취하여 적출한 흉부대동맥으로부터 혈관평활근세포를 얻었으며 이 세포를 이차배양하여 일정한 시간간격으로 trypsin을 처리하여 세포를 떼어낸후 혈구계(hemocytometer)로 세포수를 헤아렸다. 결과 : SHR과 WKY에서 얻은 혈관평활근세포에서 형태학적 차이는 없었고, SHR이 WKY보다 밀생상태에 더 빨리 도달하며 밀생상태에 도달했을때 SHR이 WKY보다 세포밀도가 더 높게 나타났다. 결론: SHR이 WKY보다 증식속도와 증식밀도가 더 높게 나타나는 것으로 보아 SHR에 성장 억제 조절 기전의 장애가 있음을 시사한다. To study the generation and processes of hypertension, characteristics of vascular smooth muscle cell were observed in cultured aortic smooth mescle cell from spontaneously hypertensive rats (SHR) and normotensive Wistar-Kyoto rats (WKY). The degree of cell proliferation increased with escalating concentrations of fetal bovine serum(FBS) in cells of both SHR and WKY control rats. These results have shown that 10% FBS, which was the usual concentration in culture medium, was better concentration of medium in cell proliferation than 5% FBS, 10% calf serum, 10% horse serum, or 1% bovine serum albumin. There were no detectable differences in the morphology of cells obtained from SHR and WKY. Comparative studies have shown that cultured vascular smooth muscle cells from SHR proliferated to a higher cell number, grew to a greater density, and have greater specific growth rate than those of the WKY. These results provide possibility of a disturbances on inhibitory conrol to vascular smooth muscle cell growth in SHR.

Acetylcholine에 의한 적출 십이지장 평활근 수축에 미치는 Calcium 길항제의 영향

손의동,이만기,박창호,김인겸,김중영 慶北大學校 醫科大學 1991 慶北醫大誌 Vol.32 No.2

To compare antagonistic action of caloium antagonists on intestinal smooth muscle contraction, acetylcholine-induced phasic contraction (PC) and tonic contraction (TC) initiated by different calcium utilization were observed in the presence of various calcium antagonists by the use of isolated mouse duodenum suspended in Tyrode's solution. By verapamil at 2.2×10 exp(-6), 2.2×10 exp(-5) and 2.2×10 exp(-4) mM, PC was more decreased dose-dependently than TC. By nifedipine at 7.9×10 exp(-5) mM, PC was more decreased than TC, but at 7.9×10 exp(-6) mM it did not affect PC and TC. By diltiazem at 6.1×10 exp(-4) mM, PC was more decreased than TC, but at 2.4×10 exp(-4) and 2.4×10 exp(-5) mM it did not affect both of the contractions. By cobalt chloride at 0.3, 1.3, and 2.6 mM, TC was significantly decreased without affecting PC, but PC markedly decreased at 5.2 mM. These results reconfirmed the fact that cobalt ion-induced calcium antagonism is more related to calcium influx process than calcium release process in contrast with the actions of verapamil, diltiazem, and nifedipine in duodenal smooth muscle.

선천성 고혈압 흰쥐와 정상혈압 흰쥐의 교감신경성 신경전달에 미치는 부신수질 및 Renin-Angiotensin계의 역할

김인겸(In Kyeom Kim),김중영(Choong Young Kim) 대한약리학회 1994 대한약리학잡지 Vol.30 No.1

선천성 고혈압 흰쥐(SHR)와 정상혈압 흰쥐에서 교감신경성 신경전달에 미치는 부신수질 및 renin-angiotensin계의 역할을 알아보기 위해, 부신수질을 제거하거나 angiotensin 변환 효소 억제제를 장기간 처치한 뒤 중추신경계가 파괴된 상태에서 절전신경을 자극했을 때 나타나는 승압반응과 대동맥의 catecholamine농도 및 angiotensin 변환 효소 활성도의 변화를 비교 검토하였다. 부신수질을 제거하더라도 중추신경계를 파괴하기 전후의 혈압에는 영향을 주지 못했으며, 절전 신경 자극에 의한 승압반응은, 자극 주파수에 의존적으로 증가하였으며 prazosin 전처치로서 거의 완전히 억제되었다. 정상혈압 흰쥐에서와는 달리, 선천성 고혈압 흰쥐에서는 부신수질을 제거했을 때는 절전신경 자극에 의한 승압반응이 부신수질을 제거하지 않는 군(이하 대조군)에 비하여 유의하게 약화되었다. SHR에서 부신수질 제거로 부신 catecholamine 함량은 현저히 감소되었고, 혈청의 angiotensin 변환 효소 활성도는 감소되는 경향을 나타내었다. 그러나 혈장 및 대동맥 절편의 catecholamine 함량, 대동맥 절편의 angiotensin 변환 효소의 활성도는 대조군과 유의한 차이가 없었다. 그러나 WKY에서는 부신수질이 제거된 군에서 대동맥 절편의 angiotensin 변환 효소의 활성도와 catecholamine함량이 대조군에 비해 유의하게 증가되어 있었다. Enalapril처치에 의해서 선천성 고혈압 흰쥐 평균 혈압은, 부신 catecholamine 함량 및 대동맥 절편의 angiotensin 변화 효소의 활성도와 함께 현저히 저하되어 정상혈압 흰쥐와 유사하였다. 그리고 선천성 고혈압 흰쥐에서 부신수질의 제거로 절전신경 자극에 의한 승압반응이 대조군에 비하여 약화되는 현상은 enalapril을 처치하였을 때는 관찰되지 않았다. 이상의 결과로 미루어보아 교감신경성 신경전달을 항진시키는 부신수질의 작용은 renin-angiotensin계의 활성화에 의존적이었으며, 부신수질의 제거로 정상혈압 흰쥐에서는 renin-angiotensin계가 보상적인 조절이 일어났으나, 선천성 고혈압 흰쥐에서는 보상적인 조절이 일어나지 않았다. To assess the role of adrenal medulla and renin-angiotensin system in the regulation of sympathetic neurotransmission, the pressor response to PNS was evaluated in pithed SHR and normotensive WKY or SDR with or without adrenal demedullation and/or enalapril pretreatment. Three weeks after adrenal demedullation, MAP and the heart rate of demedullated rats were similar to their corresponding sham-operated groups. The pressor response to PNS was frequency-dependent, and blocked by prazosin. In contrast to the normotensive rats, in SHR, the pressor response to PNS was attenuated in demedullated rats as compared with sham-operated rats. However, the attenuation of PNS-induced pressor responses in demedullated SHR was not observed in enalapril-treated SHR. The adrenal demedullation in SHR did not affect the plasma and aortic catecholamine contents in spite of the decreased catecholamine contents of adrenal gland, nor ACE activity in aortic strips. But, in WKY rats, the aortic catecholamines, especially epinephrine, contents as well as ACE activity were increased by adrenal demedullation. These results suggest that the facilitatory role of adrenal medulla in sympathetic neurotransmission depends upon the activation of renin-angiotensin system, and that the compensatory regulation of renin-angiotensin system takes place in normotensive rats but not in SHR.

Regulatory Role of Adrenal Medulla and Renin-Angiotensin System in Sympathetic Neurotransmission in Spontaneously Hypertensive and Normotensive Rats

김인겸,김중영,Kim, In-Kyeom,Kim, Choong-Young The Korean Society of Pharmacology 1994 대한약리학잡지 Vol.30 No.1

선천성 고혈압 흰쥐(SHR)와 정상혈압 흰쥐에서 교감신경성 신경전달에 미치는 부신수질 및 renin-angiotensin계의 역할을 알아보기 위해, 부신수질을 제거하거나 angiotensin 변환 효소 억제제를 장기간 처치한 뒤 중추신경계가 파괴된 상태에서 절전신경을 자극했을 때 나타나는 승압반응과 대동맥의 catecholamine농도 및 angiotensin 변환 효소 활성도의 변화를 비교 검토하였다. 부신수질을 제거하더라도 중추신경계를 파괴하기 전후의 혈압에는 영향을 주지 못했으며, 절전 신경 자극에 의한 승압반응은, 자극 주파수에 의존적으로 증가하였으며 prazosin 전처치로서 거의 완전히 억제되었다. 정상혈압 흰쥐에서와는 달리, 선천성 고혈압 흰쥐에서는 부신수질을 제거했을 때는 절전신경 자극에 의한 승압반응이 부신수질을 제거하지 않는 군(이하 대조군)에 비하여 유의하게 약화되었다. SHR에서 부신수질 제거로 부신 catecholamine 함량은 현저히 감소되었고, 혈청의 angiotensin 변환 효소 활성도는 감소되는 경향을 나타내었다. 그러나 혈장 및 대동맥 절편의 catecholamine 함량, 대동맥 절편의 angiotensin 변환 효소의 활성도는 대조군과 유의한 차이가 없었다. 그러나 WKY에서는 부신수질이 제거된 군에서 대동맥 절편의 angiotensin 변환 효소의 활성도와 catecholamine함량이 대조군에 비해 유의하게 증가되어 있었다. Enalapril처치에 의해서 선천성 고혈압 흰쥐 평균 혈압은, 부신 catecholamine 함량 및 대동맥 절편의 angiotensin 변화 효소의 활성도와 함께 현저히 저하되어 정상혈압 흰쥐와 유사하였다. 그리고 선천성 고혈압 흰쥐에서 부신수질의 제거로 절전신경 자극에 의한 승압반응이 대조군에 비하여 약화되는 현상은 enalapril을 처치하였을 때는 관찰되지 않았다. 이상의 결과로 미루어보아 교감신경성 신경전달을 항진시키는 부신수질의 작용은 renin-angiotensin계의 활성화에 의존적이었으며, 부신수질의 제거로 정상혈압 흰쥐에서는 renin-angiotensin계가 보상적인 조절이 일어났으나, 선천성 고혈압 흰쥐에서는 보상적인 조절이 일어나지 않았다. To assess the role of adrenal medulla and renin-angiotensin system in the regulation of sympathetic neurotransmission, the pressor response to PNS was evaluated in pithed SHR and normotensive WKY or SDR with or without adrenal demedullation and/or enalapril pretreatment. Three weeks after adrenal demedullation, MAP and the heart rate of demedullated rats were similar to their corresponding sham-operated groups. The pressor response to PNS was frequency-dependent, and blocked by prazosin. In contrast to the normotensive rats, in SHR, the pressor response to PNS was attenuated in demedullated rats as compared with sham-operated rats. However, the attenuation of PNS-induced pressor responses in demedullated SHR was not observed in enalapril-treated SHR. The adrenal demedullation in SHR did not affect the plasma and aortic catecholamine contents in spite of the decreased catecholamine contents of adrenal gland, nor ACE activity in aortic strips. But, in WKY rats, the aortic catecholamines, especially epinephrine, contents as well as ACE activity were increased by adrenal demedullation. These results suggest that the facilitatory role of adrenal medulla in sympathetic neurotransmission depends upon the activation of renin-angiotensin system, and that the compensatory regulation of renin-angiotensin system takes place in normotensive rats but not in SHR.

경북대학교 의과대학의 문제중심학습 시행과 그 평가

장봉현(Bong Hyun Chang),이유철(Yoo Chul Lee),김보완(Bo Wan Kim),강덕식(Duk Sik Kang),곽연식(Yun Sik Kwak),강이철(E-cheol Kang),서강석(Kang Suk Seo),김인겸(In Kyeom Kim),이종명(Jong Myung Lee),정성훈(Sung Hoon Jeong),김종열(Jong Yeol 한국의학교육학회 2001 Korean journal of medical education Vol.13 No.1

문제중심학습 (PBL)은 주어진 실제 환자문제를 학생 스스로 파악하여 학습과제를 설정하며, 학습한 내용을 논리적으로 적용하여 타당한 가설을 세워가는 과정을 거침으로써 학습이 이루어지는 새로운 교육 방법이다. 경북대학교 의과대학은 PBL을 도입하기 위하여 캐나다의 McMaster 의과대학을 단기 방문하여 그곳의 의학교육을 경험하고 PBL의 필요성을 절감하여, 1994년부터 2년간 시범적으로 PBL 수업을 운영한 후, 2년간 평가와 보완기간을 가졌다. 1994년부터 1996년까지 전학기에는 4학년과 3학년, 후학기에는 3학년과 2학년을 대상으로 6명을 한 조로, 45개의 소그룹을 만들고, 각 조에는 한 명의 지도교수를 배정하여 격주로 목요일 4교시에 PBL수업을 진행하였다. 설문조사 결과 4학년은 55.1%가, 3학년은 61.4%가 PBL이 필요하다고 응답하였으며 교수들은 83.9%가 필요하다고 답하였다. 이와 같은 결과에 근거하여 1999년도부터 시작하는 개편된 의학교육과정에 PBL이 정규과목으로 채택되었고, 이에 대비하여 1998년도 2학기에 의예과 2학년 학생을 대상으로 하여 PBL을 시행하여 그 결과를 평가하였다. 1999년도에는 의학과 1학년을 대상으로, 2000년도에는 의학과 2학년까지의 학생을 대상으로 PBL수업을 실시하였다. 본 연구자들의 조사에서, 학생들이 PBL에 대하여 상당히 이해하고 있으며, PBL의 학습목적을 대부분 달성한 것으로 나타나, 정규과목으로서의 PBL 시행에 전반적으로 긍정적인 평가를 한 것으로 판단되며, 조사결과에서 나타난 단점과 부족한 부분을 보완하고 개선한다면 PBL를 정착시키고 점차 확대 시행할 수 있을 것으로 생각된다. The effectiveness of Problem-based Learning (PBL) in medical education has already been acclaimed widely. Representatives of the curriculum committee at Kyungpook National University School of Medicine paid a visit to McMaster University School of Medicine in Canada in May, 1994 in order to learn mechanics and effectiveness of PBL in its medical education and they were impressed by the efficacy of PBL. Soon after that the school launched a pilot PBL tutorial for two years from 1994 through 1996 (4-semester) as a non-credit course for senior, junior and sophomore in medical school during one semester each, to introduce PBL to faculty members and students as well. After the pilot, opinion survey on PBL from both faculty and students revealed affirmative for PBL from 55.1% of seniors, 61.4% of juniors and 83.9% of faculty members. The faculty body at medical school was then encouraged by the pilot experience and decided to include the PBL as the part of medical education reform. During the fall semester in 1998, the senior at pre-medical course was given PBL experience to prepare for implementation of PBL at school of medicine. The PBL was implemented as an essential 2-credit-hour course in each semester commencing in 1999 to the freshmen class throughout the year; it was extended to the sophomore in 2000 and to the junior in 2001. Although there had been initial excitements of over expectations, confusion, and disappointments from faculty members and students, majority opinion of both parties on continuation of PBL was positive. The issues to be settled are preparation of study cases, students learning resources, and method of evaluating students performance. The PBL was started as an essential course in medical school in 1999 after 4 years of preparation and on the basis of our interim evaluations the following conclusions were made: we have reached the following consensus that students seem to follow the objectives of PBL and new PBL tutorial has well been accepted by students; and enhancing the program by correcting currently known weaknesses, the PBL tutorials could further be expanded to be a major modality of teaching in our medical school.

Gene Expression of Intrarenal Renin-angiotensin System in Streptozotocin-induced Diabetic Rats

Yang, Eun-Kyoung,Kim, In-Kyeom The Korean Society of Pharmacology 1997 The Korean Journal of Physiology & Pharmacology Vol.1 No.1

In humans and many animal models with chronic progressive renal diseases, angiotensin-converting enzyme (ACE) inhibitor markedly attenuates the progression of nephropathy. Several studies have reported augmented gene expression and redistribution of renal renin in partial nephrectomized rats. Although precise mechanism(s) is not known, the renin-angiotensin system (RAS) may play an important role in the progression of renal diseases. Thus, this study was undertaken to examine the gene expression of renal renin, angiotensinogen, and $AT_1$ subtypes ($AT_{1A}$ and $AT_{1B}$) in rats with diabetic nephropathy, and the influences of lipopolysaccharide (LPS)-induced septicemia on the gene expression. Four weeks after streptozotocin (STZ) treatment (55 mg/kg, i.p.), rats were randomly divided into LPS-treated (1.6 mg/kg, i.p.) and control rats. At 6 hours after LPS treatment, the rats were killed and the kidney was removed from each rat. Northern blot and reverse transcription-polymerase chain reaction (RT-PCR)techniques were used to detect mRNA expression. STZ treatment markedly attenuated body weight gain and significantly increased blood glucose level. Renal renin content (RRC) was significantly decreased in the STZ-treated rats compared to that in control rats. The renal ACE activity between STZ-treated and control rats was not significantly different. Renal renin mRNA level was prominently increased, while angiotensinogen and $AT_{1A}$ mRNA levels were slightly decreased in STZ-treated rats compared to those in controls. $AT_1$B mRNA level did not differ in both groups. Acute LPS treatment did not show any significant changes of mRNA levels of intrarenal RAS components in both groups. These results suggest that intrarenal RAS components were differentially regulated in STZ-treated diabetic rats. Further studies are required to evaluate the relationship between intrarenal RAS and other vasomodulatory systems.

Histone deacetylase inhibition attenuates hepatic steatosis in rats with experimental Cushing's syndrome

Kim, Mina,Lee, Hae-Ahm,Cho, Hyun-Min,Kang, Seol-Hee,Lee, Eunjo,Kim, In Kyeom The Korean Society of Pharmacology 2018 The Korean Journal of Physiology & Pharmacology Vol.22 No.1

Cushing's syndrome (CS) is a collection of symptoms caused by prolonged exposure to excess cortisol. Chronically elevated glucocorticoid (GC) levels contribute to hepatic steatosis. We hypothesized that histone deacetylase inhibitors (HDACi) could attenuate hepatic steatosis through glucocorticoid receptor (GR) acetylation in experimental CS. To induce CS, we administered adrenocorticotropic hormone (ACTH; 40 ng/kg/day) to Sprague-Dawley rats by subcutaneous infusion with osmotic mini-pumps. We administered the HDACi, sodium valproate (VPA; 0.71% w/v), in the drinking water. Treatment with the HDACi decreased steatosis and the expression of lipogenic genes in the livers of CS rats. The enrichment of GR at the promoters of the lipogenic genes, such as acetyl-CoA carboxylase (Acc), fatty acid synthase (Fasn), and sterol regulatory element binding protein 1c (Srebp1c), was markedly decreased by VPA. Pan-HDACi and an HDAC class I-specific inhibitor, but not an HDAC class II a-specific inhibitor, attenuated dexamethasone (DEX)-induced lipogenesis in HepG2 cells. The transcriptional activity of Fasn was decreased by pretreatment with VPA. In addition, pretreatment with VPA decreased DEX-induced binding of GR to the glucocorticoid response element (GRE). Treatment with VPA increased the acetylation of GR in ACTH-infused rats and DEX-induced HepG2 cells. Taken together, these results indicate that HDAC inhibition attenuates hepatic steatosis through GR acetylation in experimental CS.

Quantitative light-induced fluorescence technology for quantitative evaluation of tooth wear

Kim, Sang-Kyeom,Lee, Hyung-Suk,Park, Seok-Woo,Lee, Eun-Song,de Josselin de Jong, Elbert,Jung, Hoi-In,Kim, Baek-Il SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS 2017 JOURNAL OF BIOMEDICAL OPTICS Vol.22 No.12

<P>Various technologies used to objectively determine enamel thickness or dentin exposure have been suggested. However, most methods have clinical limitations. This study was conducted to confirm the potential of quantitative light-induced fluorescence (QLF) using autofluorescence intensity of occlusal surfaces of worn teeth according to enamel grinding depth in vitro. Sixteen permanent premolars were used. Each tooth was gradationally ground down at the occlusal surface in the apical direction. QLF-digital and swept-source optical coherence tomography images were acquired at each grinding depth (in steps of 100 mu m). All QLF images were converted to 8-bit grayscale images to calculate the fluorescence intensity. The maximum brightness (MB) values of the same sound regions in grayscale images before (MBbaseline) and phased values after (MBwom) the grinding process were calculated. Finally, 13 samples were evaluated. MBwom increased over the grinding depth range with a strong correlation (r = 0.994, P < 0.001). In conclusion, the fluorescence intensity of the teeth and grinding depth was strongly correlated in the QLF images. Therefore, QLF technology may be a useful non-invasive tool used to monitor the progression of tooth wear and to conveniently estimate enamel thickness. (C) 2017 Society of Photo-Optical Instrumentation Engineers (SPIE)</P>

Calcium chloride 첨가에 의한 적출장관수축에 미치는 Calcium 통로차단제의 영향

김형수,한형수,김인겸,이만기,김중영 慶北大學校 醫科大學 1992 慶北醫大誌 Vol.33 No.2

Calcium chloride 첨가에 의하여 야기되는 평활근 수축에 이용되는 calcium이온이 주로 어떤 경로를 통하여 유입되는지를 관찰하기 위하여, 마우스의 적출십이지장을 calcium-free 및 calcium-potassium-free Tyrode용액에 현수하여 수축이 소실된 상태에서, calcium chloride(4mM)를 첨가하여 야기되는 초기회복 및 후기회복의 수축긴장도의 변화를 calcium통로차단제인 diltiazem, nifedipine 및 verapamil 존재하에서 비교하였던바 다음과 같은 결과를 얻었다. Calcium-free용액에 calcium chloride를 첨가하는 조작을 각각 4회 반복하였던바 초기회복이 초회에 비하여 차후의 조작에서는 증가되는 경향을 나타내었고, 초회의 후기회복이 점차로 증가되는 현상은 차후의 조작에서는 나타나지 않았다. Calcium-potassium-free용액에서는 초회의 초기 및 후기회복 양상이 4회 반복조작으로 변화되지 아니하였다. Calcium-free용액에 calcium chloride첨가에 의하여 야기되는 초기회복은 diltiazem(3.3×10 exp (-4) 및 6.6×10 exp (-4)mM) 존재로서 거의 변화가 없었으나, 후기회복은 억제되는 경향을 나타내었다. Calcium-potassium-free용액에서도 diltiazem에 의한 초기회복은 영향을 받지 아니하였으나 후기회복은 현저한 억제현상이 나타났다. 상기한 두가지 용액중에서 nifedipine(4.3×1 exp (-5) 및 8.6×10 exp (-5)mM)를 사용하였을 경우에도 초기회복은 거의 영향을 받지 아니하고 후기회복은 억제되었다. Calcium-free용액에서 verapamil(1.2×10 exp (-4) 및 2.9×10 exp (-4)mM)를 사용하였을 경우에도 후기회복이 억제되었고, calcium-potassium-free용액에서는 calcium chloride첨가로서 야기되는 초기회복이 verapamil 2.9×10 exp (-4)mM에서는 거의 영향을 받지 아니하였으나, 1.2×10 exp (-4)mM에서는 억제되는 경향을 나타내었다. 이상의 결과로 미루어 calcium-free용액에서 calcium chloride첨가로서 야기되는 초기회복기의 수축에 비하여, 후기회복기의 수축에 관여하는 calcium은 voltage-dependent calcium통로로 유입되는 calcium이온을 많이 이용하는 것으로 생각된다. To evaluate utilization of added calcium chloride, calcium chloride-induced initial recovery and late recovery responses in isolated mouse duodenum were observed in the presence of calcium channel antagonists. Depressed tension of isolated duodenum incubated with calcium-free Tyrode solution was regained by the additon of calcium chloride (4mM). The recovery showed two phase, initial sudden recovery followed by late sustained recovery. Initial recovery by calcium chloride addition to calcium-free solution was not affected by the presence of diltiazem (3.3 × 10 exp (-4) and 6.6 × 10 exp (-4) mM), and the late recovery was tend to be depressed. In calcium-potassium-free solution, the initial recovery was not affected, however, late recovery was markedly depressed. The initial recovery in calcium-free, and calcium-potassium-free solution was little affected by the presence of nifedipine(4.3 × 10 exp (-5) and 8.6 × 10 exp (-5) mM), while the late recovery was more depressed in calcium-free solution than in calcium-potassium-free solution. The initial recovery in calcium-free solution was little affected by the presence of verapamil(12. × 10 exp (-4) and 2.9 × 10 exp (-4) mM), but the late recovery was depressed, however, the initial recovery in calcium-potassium free solution was depressed by verapamil at 1.2 × 10 exp (-4) mM, but not at 2.9 × 10 exp (-4) mM. These results indicate that calcium-channel antagonists inhibit .late recovery phase rather than initial recovery phase induced by addition of calcium chloride regardless to the presence of physiologic concentration of potassium ions in calcium free solution.