• 제목/요약/키워드: Dose Response Curve

검색결과 149건 처리시간 0.021초

동맥근 수축에 대학 Oxybutynin의 이완효과에 관한 연구 (Study on Relaxing Effect of Oxybutynin on the Contractile Response of Arterial Smooth Muscle)

  • 고재기;백영홍
    • 대한약리학회지
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    • 제24권1호
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    • pp.93-101
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    • 1988
  • 돼지 우관상동백을 적출하여 항경련제인 oxybutynin의 약리작용을 조사하였다. 1. Acetylcholine (ACh)과 KCl은 관상동맥을 수축시켰고 이 수축효과는 용량의존적이었다. ACh의 수축효과는 내피손상표본 $(EC_{50}=0.52\;{\mu}M)$에서 내피표본 $(EC_{50}=0.52\;{\mu}M)$보다 약 2배 강화되있으나 KCl의 수축효과는 양군간에 차이가 없었다. 2. $ACh(1.0\;{\mu}M)$의 수축효과는 oxybutynin과 atropine에 의 하여 용량의존적으로 억제되었고 두 약물의 $(IC_{50}$는 각각 11.0 nM과 0.47 nM로 atropine이 약 23배나 더 예민하였다. 그러나 KCl (35 mM)의 수축효과는 atropine으로는 전혀 영향받지 않았고 oxybutynin으로는 용량의존적으로 억제 되었으며 $(IC_{50}=49.7\;{\mu}M)$이였다. 3. ACh의 용량반응곡선은 oxybutynin $(IC_{50}=11\;nM)$ 및 atropine $(IC_{50}=0.47\;nM)$ 전처 리 하에서 우측으로 평 행 이 동되 있고, KCI의 용량반응곡선은 oxybutynin $(IC_{50}=49.7\;nM)$ 전처리하에서 우측으로 비상경적 이동을 일으켰다. 4. Oxybutynin은 Bay K 8644 $(0.1\;{\mu}M)$의 수축효과를 용량의존적 으로 억제하였고 $(IC_{50}=63.0\;{\mu}M)$이었으며 , histamine $(35\;{\mu}M)$의 수축효과는 oxybutynin의 최대량 $(500\;{\mu}M)$으로 부분억제 (최대 50%)만을 일으켰다. 이상의 성적으로 적출돼지 관상동백에서 내피세포는 ACh에 의한 수축반응에 억제적 영향을 미치며, oxybutynin은 강력한 muscarine receptor 차단작용과 calcium influx 억제작용에 의하여 혈관근 이완을 일으킨다고 추론하였다.

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좌골신경 만성협착손상 흰쥐에서 척수강 내로 투여된 Zaprinast의 항이질통 효과 (The Antiallodynic Effects of Intrathecal Zaprinast in Rats with Chronic Constriction Injury of the Sciatic Nerve)

  • 이재도;전인구;최윤식;임소현;박종연
    • The Korean Journal of Pain
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    • 제22권1호
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    • pp.16-20
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    • 2009
  • Background: Zaprinast is an inhibitor of phosphodiesterase 5, 6 and 9. Phosphodiesterase inhibitors could produce anti-nociceptive effects by promoting the accumulation of cGMP. We hypothesized that intrathecal zaprinast could attenuate the allodynia induced by chronic constriction injury of the sciatic nerve in rat. Methods: Sprague-Dawley rats were prepared with four loose ligations of the left sciatic nerve just proximal to the trifurcation into the sural, peroneal and tibial nerve branches. Tactile allodynia was measured by applying von Frey filaments to the lesioned hindpaw. The thresholds for the withdrawal responses were assessed. Zaprinast ($3-100{\mu}g$) was administered intrathecally by the direct lumbar puncture method to obtain the dose-response curve and the 50% effective dose ($ED_{50}$). Measurements were taken before and 15, 30, 45, 60, 90, 120, and 180 min after the intrathecal doses of zaprinast. The side effects were also observed. Results: Intrathecal zaprinast resulted in a dose-dependent antiallodynic effect. The maximal effects occurred within 15-30 min and then they gradually decreased down to the baseline level over time in all the groups. There was a dose dependent increase in the magnitude and duration of the effect. The $ED_{50}$ value was $17.4{\mu}g$ (95% confidence intervals; $14.7-20.5{\mu}g$). No severe motor weakness or sedation was observed in any of the rats. Conclusions: Intrathecally administered zaprinast produced a dose-dependent antiallodynic effect in the chronic constriction injury neuropathic pain model. These findings suggest that spinal phosphodiesterase 5, 6 and 9 may play an important role in the modulation of neuropathic pain.

마우스 소뇌과립층의 apoptosis를 지표로 한 진단용 초음파의 안전성 검증 (The evaluation on the biological safety of diagnostic ultrasound using radiation-induced apoptosis in the external granular layer of mouse cerebellum)

  • 오헌;이송은;양정아;조성기;정치영;손창호;김성호
    • 대한수의학회지
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    • 제39권3호
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    • pp.628-634
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    • 1999
  • We have studied, by a nonisotopic in situ end-labeling(ISEL) technique, frequency of apoptosis in the external granular layer(EGL) of the cerebellum of immature mice by ${\gamma}$-rays irradiation from $^{60}Co$ or diagnostic ultrasound exposure. The total number of normal cells and cells showing morphological features of apoptosis were counted. The frequency of apoptotic cells was expressed as a percentage of the total number of cells in EGL. The extent of changes following 200 cGy(1090 cGy/min) was studied at 2, 4, 6, 8, 12, or 24 hours after exposure. The maximal frequency was found 6~8 hours after exposure. The immature mice that received 18, 36, 54, 108, 198, 396 cGy of ${\gamma}$-rays or diagnostic ultrasound(7.5MHz, 4.2mW, $I_{SPTA}=7.9mW/cm^2$, $I_{SPTA}=114.3W/cm^2$) for 10 or 30 minutes were examined 6 hours after irradiation. Measurements performed after ${\gamma}$-ray irradiation showed a dose-related increase in apoptotic cells in each of the mice studied. The dose-response curves were analyzed by a linear-quadratic model ; frequency of apoptotic cell in the EGL was y = $(0.1349{\pm}0.01175)D$+$(-0.0001522{\pm}0.0000334)D^2$+0.048($r^2$ = 0.981, D = dose in cGy). In the experiment of ultrasound exposure, the frequency of apoptotic cell was $0.106{\pm}0.130$(10 minutes exposure) and $0.167{\pm}0.220$(30 minutes exposure). We estimated the relative dose of the yield from the experiment with ultrasound by substituting the yield from ultrasound exposure into the curve from the ${\gamma}$-irradiation. The relative dose of ultrasound exposure compared with ${\gamma}$-irradiation were 0.432 cGy(10 minutes exposure) and 0.885 cGy(30 minutes exposure). We have found that there is no evidence to indicate that diagnostic ultrasound involves a significant risk.

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Inhibitory activity of Euonymus alatus against alpha-glucosidase in vitro and in vivo

  • Lee, Soo-Kyung;Hwang, Ji-Yeon;Song, Ji-Hyun;Jo, Ja-Rim;Kim, Myung-Jin;Kim, Mi-Eun;Kim, Jung-In
    • Nutrition Research and Practice
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    • 제1권3호
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    • pp.184-188
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    • 2007
  • The major goal in the treatment of diabetes mellitus is to achieve near-normal glycemic control. To optimize both fasting blood glucose and postprandial glucose levels is important in keeping blood glucose levels as close to normal as possible. ${\alpha}-Glucosidase$ is the enzyme that digests dietary carbohydrate, and inhibition of this enzyme could suppress postprandial hyperglycemia. The purpose of this study was to test the inhibitory activity of methanol extract of Euonymus alatus on ${\alpha}-glucosidase$ in vitro and in vivo to evaluate its possible use as an anti-diabetic agent. Yeast ${\alpha}-glucosidase$ inhibitory activities of methanol extract of E. alatus were measured at concentrations of 0.50, 0.25, 0.10, and 0.05 mg/ml. The ability of E. alatus to lower postprandial glucose was studied in streptozotocin-induced diabetic rats. A starch solution (1 g/kg) with and without E. alatus extract (500 mg/kg) was administered to diabetic rats by gastric intubation after an overnight fast. Plasma glucose levels were measured at 30, 60, 90, 120, 180, and 240 min. Plasma glucose levels were expressed in increments from baseline, and incremental areas under the response curve were calculated. Extract of E. alatus, which had an $IC_{50}$ value of 0.272 mg/ml, inhibited yeast ${\alpha}-glucosidase$ activity in a concentration-dependent manner. A single oral dose of E. alatus extract significantly inhibited increases in blood glucose levels at 60 and 90 min (p<0.05) and significantly decreased incremental response areas under the glycemic response curve (p<0.05). These results suggest that E. alatus has an antihyperglycemic effect by inhibiting ${\alpha}-glucosidase$ activity in this animal model of diabetes mellitus.

고관전압 흉부촬영의 가상결절을 이용한 ROC평가 (Evaluation of ROC Curve in High Kilovoltage Technique Using Simulated Nodules on Chest)

  • 안진신;장명미;정경모;정환;임정기;김종효
    • 대한방사선기술학회지:방사선기술과학
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    • 제15권2호
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    • pp.25-30
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    • 1992
  • With transmitted dose through chest which has the problem of wide variations in absorption, simple film/screen combination method makes it diffucult to image lung field, mediastinum and retrocardiac areas. In order to overcome this, it is very common to use the high kilovoltage technique in diminishing the differences between high and low contrast. We have been adopting this method at department of diagnostic radiology, Seoul National University Hospital. To compare the image of it with that of low kilovoltage technique, we did radiographic tests using beans on the skin. We marked off into three anatomical categories such as lungs, mediastinum and near diaphragm, then attached a bean on a marked area at random. In order to compare with high and low, we took a radiography of high($120{\sim}140\;kVp$) and low($70{\sim}90\;kVp$) kilovoltage tehchniques, respectively at the same time. We have done experiments 320 cases. We evaluated the results of test in response to sensitivity(true positive) and specificity(true negative). In evaluating, we gave them points from 1 to 5 according to true or false. With given points by a radiologist having much experiences, we could acquire the percentage of sensitivity and specificity. The percentage made us to get the schematic table of ROC curve of those two methods. Consequently, high kilovoltage technique appeared 18% better than low kilovoltage technique for detecting beans with our apparatus.

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Competitive Enzyme-Linked Immunosorbent Assay for Glucose-6-Phosphate Dehydrogenase

  • Kim, Moon-Hee
    • BMB Reports
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    • 제30권5호
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    • pp.326-331
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    • 1997
  • To construct a competitive ELISA standard curve for the detection of glucose-6-phosphate debydrogenase (G6PD), we used highly purified native G6PD (nG6PD) as both immobilized and soluble antigens and anti-G6PD serum raised against nG6PD as antibody. The polystyrene cuvettes coated with nG6PD were challenged with a mixture of a limiting amount of anti-G6PD serum and various doses of nG6PD as competitors followed by incubation with alkaline phosphatase-anti-IgG conjugate. The competitive ELISA did not exhibit the typical sigmoidal dose-response curve characteristic of competition immunoassays under the optimal concentrations of antigen and antibody. The soluble nG6PD used as competitor failed to effectively inhibit the binding of antibodies to the immobilized nG6PD. The addition of NADP, a cofactor of G6PD enzyme, to coating buffer used for immobilizing nG6PD to the cuvettes and PBS-Tween-BSA buffer for diluting competitors did not improve the inhibition of antibody binding to immobilized nG6PD by soluble n/G6PD. The addition of BSA to coating buffer did not increase inhibition, either. Surprisingly, when partially active G6PD (paG6PD), obtained by repeated freeze-thawing, was used as competitor, the antibody binding to either immobilized nG6PD or immobilized paG6PD was inhibited 49-58%. We conclude that an effective competitive ELISA system with nG6PD enzyme and anti-G6PD serum for the detection of G6PD may not be established due to the poor inhibition of antibody binding to immobilized nG6PD by soluble nG6PD under the present assay conditions and that the inhibition may be improved by using an inactivated enzyme as competitor regardless of the type of immobilized antigen used. These results imply that the immobilized nG6PD may undergo denaturation upon binding to the polystyrene cuvettes and that our anti-G6PD serum may recognize denatured enzyme better than active enzyme.

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Evaluation of DNA Fragments on Boar Sperm by Ligation-mediated Quantitative Real Time PCR

  • Lee, Eun-Soo;Choi, Sun-Gyu;Yang, Jae-Hun;Bae, Mun-Sook;Park, Jin-Young;Park, Hong-Min;Han, Tae-Kyu;Hwang, You-Jin;Kim, Dae-Young
    • 한국수정란이식학회지
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    • 제25권2호
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    • pp.111-116
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    • 2010
  • Sperm chromatin integrity is essential for successful fertilization and development of an embryo. Reported here is a quantification of DNA fragments which is intimately associated with reproductive potential to provide one of criteria for sperm chromatin integrity. Three sperm populations were considered: CONTROL (no treatment), UV irradiation (48mW/$cm^2$, 1h) and $H_2O_2$ (oxidative stress induced by hydrogen peroxide, 10 mM, 50 mM and 100 mM). DNA fragments in boar sperm were evaluated by using ligation-mediated quantitative real-time polymerase chain reaction (LM-qPCR) assay, which relies on real-time qPCR to provide a measure of blunt 5' phosphorylated double strand breaks in genomic DNA. The results in agarose gel electrophoresis showed no significant DNA fragmentation and no dose-dependent response to $H_2O_2$. However, the remarkable difference in shape and position was observed in melting curve of LM-qPCR. This result supported that the melting curve analysis of LM-qPCR presented here, could be more sensitive and accurate than previous DNA fragmentation assay method.

선천성 부분 신성 요붕증 1례 (A Case of Congenital Partial Nephrogenic Diabetes Insipidus)

  • 모은하;남인혜;정민자;유재홍
    • Clinical and Experimental Pediatrics
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    • 제45권7호
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    • pp.902-905
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    • 2002
  • 선천성 신성 요붕증은 일반적으로 성염색체 열성 유전 양식을 취하여 보인자인 어머니로부터 아들에게 유전되고, 발생 빈도는 드문 것으로 알려져 있으며, 항이뇨호르몬의 혈장 농도가 정상이거나 상승되어 있으면서도 신세뇨관이 항이뇨호르몬에 대한 저항성 때문에 요농축능 장애가 발생하여 다음과 다뇨를 특징으로 하는 질환으로 이뇨제와 프로스타글란딘 합성억제제의 사용이 치료의 근간을 이루어 왔다. 본 증례에서 발견된 AVPR2 수용체 유전자의 돌연변이 부위는 선천성 신성 요붕증의 표현형을 보이는 것으로 외국에서는 보고된 바 있으나 국내에서는 최초로 확인된 것이며, 고용량의 항이뇨 호르몬과 이뇨제 치료에 반응을 보였다.

Participation of $K_{ATP}$ Channels in the Antinociceptive Effect of Pregabalin in Rat Formalin Test

  • Kweon, Tae-Dong;Kim, Ji-Young;Kwon, Il-Won;Choi, Jong-Bum;Lee, Youn-Woo
    • The Korean Journal of Pain
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    • 제24권3호
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    • pp.131-136
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    • 2011
  • Background: Pregabalin is an anticonvulsant and analgesic agent that interacts selectively with the voltage-sensitive-$Ca^{2+}$-channel alpha-2-delta subunit. The aim of this study was to evaluate whether the analgesic action of intrathecal (IT) pregabalin is associated with KATP channels in the rat formalin test. Methods: IT PE-10 catheters were implanted in male Sprague-Dawley rats (250.300 g) under inhalation anesthesia using enflurane. Nociceptive behavior was defined as the number of hind paw flinches during 60 min after formalin injection. Ten min before formalin injection, IT drug treatments were divided into 3 groups: normal saline (NS) $20\;{\mu}l$ (CON group); pregabalin 0.3, 1, 3 and $10\;{\mu}g$ in NS $10\;{\mu}l$ (PGB group); glibenclamide $100\;{\mu}g$ in DMSO $5\;{\mu}l$ with pregabalin 0.3, 1, 3 and $10\;{\mu}g$ in NS $5\;{\mu}l$ (GBC group). All the drugs were flushed with NS $10\;{\mu}l$. Immunohistochemistry for the $K_{ATP}$ channel was done with a different set of rats divided into naive, NS and PGB groups. Results: IT pregabalin dose-dependently decreased the flinching number only in phase 2 of formalin test. The log dose response curve of the GBC group shifted to the right with respect to that of the PGB group. Immunohistochemistry for the $K_{ATP}$ channel expression on the spinal cord dorsal horn showed no difference among the groups 1 hr after the formalin test. Conclusions: The antinociceptive effect of pregabalin in the rat formalin test was associated with the activation of the $K_{ATP}$ channel. However, pregabalin did not induce $K_{ATP}$ channel expression in the spinal cord dorsal horn.

신열판실험방법(新熱板實驗方法)에 의(依)한 Naloxone과 Diazepam이 Morphine 진통효과(鎭痛效果)에 미치는 영향(影響)에 관(關)한 검색(檢索) (A New Hot-Plate Method using Threshold Temperature; its Application on the Study of the Interaction between Naloxone or Diazepam and Morphine)

  • 문영환;전보권
    • 대한약리학회지
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    • 제18권2호
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    • pp.45-50
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    • 1982
  • Yeum et al. formulated a new hot-plate method using the threshold temperature, and there are some controversies on the effects of naloxone and diazepam on the antinociceptive action. In this paper, the comparison of three methods registering analgesic activity and the application of the new hot-plate method formulated by Yeum et al. on the study of the influences of naloxone and diazepam on the analgesic effect of morphine were tried in male mice. The results obtained were summarized as follows; 1) The least-square regression lines of the morphine analgesia plotted against log-dose showed the correlation coefficient of above 0.90, but the competitive antagonism produced by naloxone (0.1 mg/kg) against the analgesia was more prominently demonstated by the new hot-plate method than the other methods: original hot-plate method and electrical stimulation method. 2) In the experiment using the new hot-plate method, the log dose-response curve of morphine (y=7.30 x+49.80, r=0.998) was shifted to the right by the pretreatment of naloxone (0.1 mg/kg), but was slightly shifted to the left by the pretreatment of diazepam (2.5 mg/kg). This study suggests that for the analgesia experiment, the new hot-plate method is superior to the original hot-plate method or the electrical stimulation method, and that the potentiative effect of diazepam on the morphine anagesia is not significant.

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