• 제목/요약/키워드: uptake rate

검색결과 1,068건 처리시간 0.032초

In Vivo 레벨에서 1-아닐리노-8-나프탈렌 설포네이트(ANS)의 간내 이행 및 담즙배설 과정의 속도론적 해석 (Kinetic Analysis of the Hepatic Uptake and Biliary Excretion of 1-Anilino-8-Naphthalene Sulfonate (ANS) in Vivo)

  • 배웅탁;정연복;한건
    • Journal of Pharmaceutical Investigation
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    • 제31권4호
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    • pp.209-216
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    • 2001
  • The purpose of the present study was to investigate the hepatic uptake and biliary excretion of l-anilino-8-naphthalene sulfonate (ANS) in vivo. The plasma concentration and liver concentration of ANS were determined after its i.v. bolus administration at a dose of $30\;{\mu}mol/kg$ in rats. The hepatic uptake clearance $(CL_{uptake})$ of ANS was 0.1 ml/min/g liver. On the basis of the unbound concentration of ANS, the permeability-surface area product $(PS_{influx})$ was calculated to be l0.4 ml/min/g liver, being comparable of in vitro data. On the other hand, we determined the plasma concentration, liver concentration and biliary excretion rate of ANS at steady-state after its i. v. infusion $(0.2-1.6\;{\mu}mol/min/kg)$ in rats. The excretion clearance $(CL_{excretion})$ of ANS showed Michaelis-Menten kinetics with increasing the infusion rate. The permeability-surface area product $(PS_{excretion})$ based on the unbound concentration in the liver was calculated to be 0.0165 ml/min/g liver, which is negligible compared with the intrinsic clearance $(CL_{int}=3.3\;ml/min/g\;liver)$ by rat liver microsomes. The sequestration process of ANS, therefore, was considered to be mainly due to the metabolic process in the liver $(PS_{seq}{\risingdotseq}CL_{int})$. Furthermore, $PS_{efflux}$ value calculated from $PS_{influx}$ and $PS_{seq}$ was 4.4 ml/min/g liver, which was comparable of in vitro data. In conclusion, in vivo parameters such as $PS_{influx}$, $PS_{efflux}$ and $PS_{seq}$ in the present study showed good in vivo-in vitro relationship. Thus, the kinetic analysis method proposed in the present study would be useful to analyze the hepatic transport of drugs in vivo.

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갑상선 섭취율 측정에서 선원의 길이와 부피 증가에 따른 영향 (The Effect of Increase in Length and Volume of Source in Radioactive Iodine Thyroid Uptake Rate)

  • 황동훈;오신현;김정열;강천구;김재삼
    • 핵의학기술
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    • 제21권1호
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    • pp.70-75
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    • 2017
  • 방사성 요오드 갑상선 섭취율 검사는 방사성 요오드를 투여하고 일정 시간 후 갑상선의 요오드 방사능치를 측정하여 전반적인 기능 상태를 알아보는 검사법이다. 검사에 영향을 미치는 인자는 매우 다양하다. 본 연구에서는 갑상선의 길이나 두께, 부피에 따른 기하학적 요인이 계수율에 주는 영향을 관찰하고자 한다. 액체상태의 $^{131}I\;185kBq$ ($5{\mu}Ci$)을 지름이 0.5, 1, 1.5, 3 cm 인 주사기에 넣고 길이를 1 cm 간격으로 생리식염수를 추가하여 증가시켰다. 선원을 장비로부터 25 cm 거리에서 횡축방향과 종축방향으로 위치하였을 때 각각의 계수율을 측정하였다. 횡축 방향으로 위치하였을 때, 선원의 길이가 변화하여도 대부분 유의한 차이를 보이지 않았다. 종축 방향으로 위치하였을 때, 곡선추정 회귀분석 결과 복합모형곡선과 높은 상관관계를 보였고($$R^2{\geq_-}0.941$$), 선원의 길이가 증가할수록 계수율은 감소하였다. 따라서 갑상선 섭취율 검사 시, 갑상선의 가로나 세로 방향의 차이에 따른 섭취율의 오차는 적을 것으로 예상되어 지며, 단순한 부피의 차이보다 갑상선의 두께 및 투여 전 선량측정 시의 비커에 따라서 오차가 생길 수 있다고 예상된다. 따라서 오차를 줄이기 위해서는 초음파 등의 영상을 참고하여 두께를 구해 섭취율 수치에 적용하거나, 결과에서 구한 복합방정식을 통해 오차를 예측, 갑상선과 섭취율 장비의 거리를 변화시킨다면 비교적 정확한 계수율을 구할 수 있을 거라 사료 된다.

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환경 변화에 따른 오이의 호흡속도에 관한 수리적 모형 (Mathematical Models of Respiration Rate of Cucumber Plants under Varying Environmental Conditions)

  • 임준택;정현희;백선영;현규환;권병선;김학진;정순주;이범선
    • 생물환경조절학회지
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    • 제9권4호
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    • pp.185-192
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    • 2000
  • 본연구는 시설내 다양한 환경조건하에서 오이의 호흡속도에 관한 수리적 모형을 개발하고자 실시하였다. 개개 오이 식물에 대한 총광합성속도의 8.55%가 호흡에 사용되었다. 생장호흡계수는 0.0935로 추정되었고 유지호흡속도는 24$^{\circ}C$ 온도에서 0.00158g C$H_2O$.g$^{-1}$.h$^{-1}$로 추정되었다. 그리고 그것은 온도상승에 따라 지수적으로 증가하였다. 호흡속도는 저장 탄수화물량이 낮아짐에 따라 비례적으로 감소했고 뿌리의 이온흡수호흡속도는 0.6648g C$H_2O$.(gN)$^{-1}$로 추정되었다.

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파보일미(Parboiled rice)의 이화학적 특성 -III. 파보일미(추청벼)의 취반 및 노화특성- (Cooking Characteristics and Firming Rate of Cooked Parboiled Rice)

  • 이명선;조은자
    • 한국식품조리과학회지
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    • 제12권1호
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    • pp.46-53
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    • 1996
  • To investigate physicochemical and cooking properties of parboiled rice, choochung paddy processed to parboiled rice by three methods (PL, PT, PA) milled and examined hydration, cooking qualities and firming rate of cooked parboiled rice. The results were obtained as follows. The longer the steaming time during parboiling the larger EMC of soaked parboiled rice. Water uptake rate constants (k) of all the parboiled rice during soaking except for PT rice were generally increased than those of raw rice. The longer the steaming time during parboiling the greater volume increase rate constants ( $k_{v}$) of parboiled rice samples. The glelatinization temperature of parboiled rice flour by DSC was more increased than that of raw rice flour. Gelatinized entalpy was decreased and gelatinization content (%SG: degree of starch gelatinization) was increased by parboiling process. In cooking tests, parboiled rices were harder than raw rice and softness (reciprocal of hardness) was greater PT30, PA, PL30 in turns the cooking time of the parboiled rice took longer 3-10 min than that of raw rice, PL30 took longer time than anyother rices. Cooking water of parboiled rices could be observed lighter turbidities than that of raw rice. Firming rate constants of cooked rice during storage 24 hours were generally decreased by parboiling-processing. The time constants, reciprocal of firming constants of cooked PL30 rice were 2 times slower than those of cooked raw rice.e.

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Effects of High Glucose Levels on the Protein Kinase C Signal Transduction Pathway in Primary Cultured Renal Proximal Tubule Cells

  • Han, Ho-Jae;Kang, Ju-Won;Park, Kwon-Moo
    • The Korean Journal of Physiology
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    • 제30권2호
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    • pp.257-267
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    • 1996
  • Diabetes mellitus is associated with a wide range of pathophysiologic changes in the kidney. This study was designed to examine the mechanisms by which glucose modulates the expression of polarized membrane transport functions in primary cultured rabbit renal proximal tubule cells. Results are as follows: The rate of 30 minute $Rb^{+}$ uptake was significantly higher($137.76{\pm}5.40%$) in primary renal tubular cell cultures treated with 20 mM glucose than that of 5 mM glucose. Not the level of mRNA for the ${\alpha}$ subunit of Na, K-ATPase but that of ${\beta}$ subunit was elevated in primary cultures treated with high glucose. The initial rate of methyl-${\alpha}$-D-glucopyranoside(${\alpha}$-MG) uptake was significantly lower($71.91{\pm}3.02%$) in monolayers treated with 20 mM glucose than that of 5 mM glucose. There was a tendency of an increase in phlorizin binding site in cells treated with 5 mM glucose. However, 3-O-methyl-D-glucose(3-O-MG) uptake was not affected by glucose concentration in culture media. TPA inhibited $Rb^{+}$ uptake by $63.61{\pm}1.94\;and\;45.80{\pm}1.36%$ and ${\alpha}$-MG uptake by $48.54{\pm}3.69\;and\;41.87{\pm}6.70%$ in the cells treated with 5 and 20 mM glucose, respectively. Also TPA inhibited mRNA expression of Na/glucose cotransporter in cells grown in 5mM glucose medium. cAMP significantly stimulated ${\alpha}$-MG uptake by $114.65{\pm}5.70%$ in cells treated with 5mM glucose, while it did not affect ${\alpha}$-MG uptake in cell treated with 20 mM glucose. However, cAMP inhibited $Rb^{+}$ uptake by $76.69{\pm}4.16\;and\;66.87{\pm}2.41%$ in cells treated with 5 and 20 mM glucose, respectively. In conclusion, the activity of the renal proximal tubular Na,K-ATPase is elevated in high glucose concentration. In contrast, the activity of the Na/glucose cotransport system is inhibited. High glucose may in part affect the activity of the Na,K-ATPase and the Na/glucose cotransport system by controlling the protein kinase C and/or A signal transduction pathway in primary cultured renal proximal tubule cells.

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포장재배수도(圃場栽培水稻)의 무기영양(無機營養) -III 수량등급별(收量等級別) 양분(養分)(N. P. K Si) 흡수량(吸收量), 양분효율(養分効率) 및 전이율(轉移率) (Mineral nutrition of field-grown rice plant. -III. Uptake, efficiency and percent translocation of N.P.K. and Si at various yield classes)

  • 박훈
    • 한국토양비료학회지
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    • 제7권2호
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    • pp.119-125
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    • 1974
  • 삼요소시험(三要素試驗)(1967~69)을 중심(中心)으로 정조수량등급별(正租收量等級別)로 N, P, K, Si의 흡수량(吸收量)과 이들의 정조생산효율(正租生産効率) 및 전이율(轉移率)을 본결과 다음과 같다. 1) 수량증가(收量增加)에 따른 각양분(各養分)의 요구도(要求度)는 유사(類似)한 비율(比率)로 증가(增加)하였으나 규산(珪酸)이 가장 변화(變化)가 컸다. 2) 질소효율(窒素効率)이 낮은(46kg/Nkg) 삼요소(三要素)시험에서는 수량(收量)이 증가(增加)할수록 효율(効率)과 전이율(轉移率)이 증가(增加)하는 경향(傾向)이다. 3) 질소흡수량(窒素吸收量)이 증가(增加)할수록 질소(窒素)의 정조생산효율(正租生産効率)이 감소(減少)하였으며 이감소정도는 비종(肥種) 및 품종(品種)에 따라 크게 다르다. 질소효율(窒素効率)은 식질(埴質)에서보다 수량(收量)이 높은 사양토(砂壤土)에서 높았다. 4) 질소(窒素)의 정조생산효율(正租生産効率)은 질소(窒素)의 인으로의 전이율(轉移率)과 정상관관계(正相關關系)였다. 5) 다수확(多收穫)은 질소효율(窒素効率)이 50정도에서 머문채 질소흡수량(窒素吸收量)만을 증가(增加)시켜 이루어지고 있다. 6) 질소효율(窒素効率)의 저하(低下)가 저수(低收)의 큰요인(要因)으로 보였다. 7) 삼요소시험(三要素試驗)에서 인산(燐酸)의 정조생산(正租生産) 효율(効率)이 상당히 낮은 편인데 인산(燐酸)의 토양환원(土壤還元)에 의(依)한 과다흡수(過多吸收)에 기인(基因)하는 것 같다.

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저온플라즈마 및 효소처리한 면의 물성 및 염색성 (Physical Properties and Dyeing Behaviors of Cotton Fabric Treated with Low Temperature Plasma and/or Cellulase)

  • Yoon, Nam Sik;Lim, Yong Jin
    • 한국염색가공학회지
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    • 제8권3호
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    • pp.59-65
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    • 1996
  • Cotton fabrics were treated by low temperature plasma and/or cellulase, and its physical and dyeing properties were investigated. All the pretreatments of the cotton with low temperature plasma of oxygen, nitrogen and argon slowed down the rate of weight loss of cotton in cellulase solution. Plasma pretreatment did not show any strength retention effect on cotton fiber in the subsequent cellulase treatment. Pretreatment of cotton with low temperature oxygen plasma decreased the rate of dyeing in direct dye bath, while cellulase or plasma/cellulase pretreatment increased the rate. Equilibrium dye uptake of cotton was not changed greatly by the pretreatments except the normal untreated cotton showed more or less high uptake. The pretreatment of cellulase with a water-soluble carbodiimide reduced the enzymatic activity, and did not show any strength retention of cotton in enzymatic weight loss.

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Effects of D-Fructose on the Uptake of Iron by the Intestinal Brush-Border Membrane Vesicles from Rats.

  • Kim, Ok-Seon;Lee, Yong-Bok;Oh, In-Joon;Koh, Ik-Bae;Lee, Yeong-Woo
    • Journal of Pharmaceutical Investigation
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    • 제24권3호spc1호
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    • pp.11-18
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    • 1994
  • We have studied the iron uptake by the purified brush-border membrane vesicles (BBMVs) to determine the effect of fructose on the absorption of iron. BBMVs were prepared by the modified calcium precipitation method, The degree of purification was routinely assessed by the marker enzyme, alkaline phosphatase, and the functional integrity was tested by $D-[1-^3H]glucose$ uptake. The appearance of membrane vesicles was shown by transmission electron microscopy (TEM). The uptakes of complexes of labeled iron $[^{59}Fe]$ with fructose and ascorbate were measured with a rapid filtration technique, The uptake rate and pattern of the two iron-complexes, Fe(III)-fructose and Fe(III)-ascorbate, were also observed. A typical overshooting uptake of D-glucose was observed with peak value of $2{\sim}3$ times higher concentration than that at equilibrium. This result was similar to other studies with BBMVs. TEM showed that the size of BBMVs was uniform and we can hardly find any contaminants, Fe(III)-fructose has the higher value of $V_{max}$ and the lower value of Km than those of Fe(III)-ascorbate, respectively. It may be concluded that D-fructose is more effective in promoting the iron absorption than ascorbate.

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Uptake efficiencies of PCB 153 in fathead minnows through food chain of sediment-midge-fish

  • Park, Kyungho;Peter G. Meier
    • 한국환경보건학회:학술대회논문집
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    • 한국환경보건학회 2003년도 Challenges and Achievements in Environmental Health
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    • pp.162-165
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    • 2003
  • Uptake efficiencies of PCB 153 in fathead minnow through food chain of sediment-midge-fish were evaluated. Contaminated fish food, the midge Chironomus plumosus was prepared by exposing to sediments with PCB 153. We could harvest the midges with body PCB 153 levels of ∼ 1.0 mg/g and ∼ 10.0 mg/g, respectively, in 2 wk of exposure. PCB 153 level in fish fed with midge of 10.0 mg/g PCB 153 (high-dose group) reached its highest at 11.2 mg/g after 30 d of exposure. However, PCB level in fish fed with midge of 1.0 mg/g PCB 153 (low-dose group) kept increasing following first order rate kinetics until the end of exposure (38 d). When the fish food was changed to the uncontaminated ones, the fish body PCB levels were stabilized in ∼ 3 wk. The uptake efficiency in high-dose fish group was 37%, whereas low-dose group was 55%. Uptake efficiencies in fathead minnows were notably lower than that of pike (∼ 70%). This finding suggests that the uptake efficiency of this PCB congener may depend on the amount of the PCB in diet.

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Uptake and Excretion of Dissolved Organic Phosphorus by Two Toxic Dinoflagellates, Alexandrium tamarense Lebour (Balech) and Gymnodinium catenatum Graham

  • Oh Seok-Jin;Yamamoto Tamiji;Yoon Yang-Ho
    • Fisheries and Aquatic Sciences
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    • 제9권1호
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    • pp.30-37
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    • 2006
  • We performed experiments on the uptake and excretion of dissolved organic phosphorus (DOP) using two toxic dinoflagellates, Alexandrium tamarense Lebour (Balech) and Gymnodinium catenatum Graham, isolated from Hiroshima Bay, Japan. ATP (adenosine triphosphate), UMP (uridine-5-monophosphate), G-6-P (glucose-6-phosphate) and Glycero-P (glycerophosphate) were used as DOP sources in preliminary uptake experiments. ATP was selected as the DOP species for the short-tenn uptake experiment because preliminary experiments showed it to be the DOP source used by both species. Although the $K_s$ values of A. tamarense and G. catenatum (5.63 and $7.61{\mu}M$, respectively) obtained from the short-term experiments for ATP were only slightly higher than those reported for dissolved inorganic phosphorus (DIP), the ${\rho}_{max}$ values (5.04 pmol/cell/h and 13.4 pmol/cell/h, respectively) were much higher. The DOP excretion rate in batch-culture experiments was estimated at 0.084 pmol/cell/h for A. tamarense and 0.012 pmol/cell/h for G. catenatum, accounting for about 30% and 25%, respectively, of the assimilated phosphorus. Our results suggest that the DIP-depleted conditions of Hiroshima Bay favor these two species by supporting their ability to use DOP.