• 제목/요약/키워드: Reabsorption

검색결과 185건 처리시간 0.02초

Cadmium Inhibition of Renal Endosomal Acidification

  • Kim, Moo-Seong;Kim, Kyoung-Ryong;Ahn, Do-Whan;Park, Yang-Saeng
    • The Korean Journal of Physiology and Pharmacology
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    • 제4권1호
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    • pp.63-72
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    • 2000
  • Chronic exposure to cadmium (Cd) results in an inhibition of protein endocytosis in the renal proximal tubule, leading to proteinuria. In order to gain insight into the mechanism by which Cd impairs the protein endocytosis, we investigated the effect of Cd on the acidification of renal cortical endocytotic vesicles (endosomes). The endosomal acidification was assessed by measuring the pH gradient-dependent fluorescence change, using acridine orange or FITC-dextran as a probe. In renal endosomes isolated from Cd-intoxicated rats, the $V_{max}$ of ATP-driven fluorescence quenching ($H^+-ATPase$ dependent intravesicular acidification) was significantly attenuated with no substantial changes in the apparent $K_m,$ indicating that the capacity of acidification was reduced. When endosomes from normal animals were directly exposed to free Cd in vitro, the $V_{max}$ was slightly reduced, whereas the $K_m$ was markedly increased, implying that the biochemical property of the $H^+-ATPase$ was altered by Cd. In endosomes exposed to free Cd in vitro, the rate of dissipation of the transmembrane pH gradient after $H^+-ATPase$ inhibition appeared to be significantly faster compared to that in normal endosomes, indicating that the $H^+-conductance$ of the membrane was increased by Cd. These results suggest that in long-term Cd-exposed animals, free Cd ions liberated in the proximal tubular cytoplasm by lysosomal degradation of cadmium-metallothionein complex (CdMT) may impair endosomal acidification 1) by reducing the $H^+-ATPase$ density in the endosomal membrane, 2) by suppressing the intrinsic $H^+-ATPase$ activity, and 3) possibly by increasing the membrane conductance to $H^+$ ion. Such effects of Cd could be responsible for the alterations of proximal tubular endocytotic activities, protein reabsorption and various transporter distributions observed in Cd-exposed cells and animals.

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Polymorphisms of SLC22A9 (hOAT7) in Korean Females with Osteoporosis

  • Ahn, Seong Kyu;Suh, Chang Kook;Cha, Seok Ho
    • The Korean Journal of Physiology and Pharmacology
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    • 제19권4호
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    • pp.319-325
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    • 2015
  • Among solute carrier proteins, the organic anion transporters (OATs) play an important role for the elimination or reabsorption of endogenous and exogenous negatively charged anionic compounds. Among OATs, SLC22A9 (hOAT7) transports estrone sulfate with high affinity. The net decrease of estrogen, especially in post-menopausal women induces rapid bone loss. The present study was performed to search the SNP within exon regions of SLC22A9 in Korean females with osteoporosis. Fifty healthy controls and 50 osteoporosis patients were screened for the genetic polymorphism in the coding region of SLC22A9 using GC-clamped PCR and denaturing gradient gel electrophoresis (DGGE). Six SNPs were found on the SLC22A9 gene from Korean women with/without osteoporosis. The SNPs were located as follows: two SNPs in the osteoporosis group (A645G and T1277C), three SNPs in the control group (G1449T, C1467T and C1487T) and one SNP in both the osteoporosis and control groups (G767A). The G767A, T1277C and C1487T SNPs result in an amino acid substitution, from synonymous vs nonsynonymous substitution arginine to glutamine (R256Q), phenylalanine to serine (F426S) and proline to leucine (P496L), respectively. The Km values and Vmax of the wild type, R256Q, P496L and F426S were 8.84, 8.87, 9.83 and $12.74{\mu}M$, and 1.97, 1.96, 2.06 and 1.55 pmol/oocyte/h, respectively. The present study demonstrates that the SLC22A9 variant F426S is causing inter-individual variation that is leading to the differences in transport of the steroid sulfate conjugate (estrone sulfate) and, therefore this could be used as a marker for certain disease including osteoporosis.

관찰연구에서 확인된 SGLT2 억제제의 심혈관질환 예방효과: 한국인의 결과를 중심으로 (Preventive Effect of an SGLT2 Inhibitor on Cardiovascular Disease in an Observational Study: Results from a Korean Population)

  • 하경화;김대중
    • 당뇨병
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    • 제19권3호
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    • pp.135-139
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    • 2018
  • The sodium-glucose cotransporter-2 inhibitor (SGLT2i) is a new anti-hyperglycemic agent that have function to concomitantly inhibit the reabsorption of glucose and sodium in the renal proximal convoluting tubule. Recent two cardiovascular outcome trials showed that a lower risk of cardiovascular events with SGLT2i in people with type 2 diabetes. In addition, prior real-world data demonstrated similar SGLT2i effects, but these studies were limited to the United States and Europe. Thus, the CVD-REAL (Comparative Effectiveness of Cardiovascular Outcomes in New Users of Sodium-Glucose Cotransporter-2 Inhibitors) 2 Study was investigated cardiovascular outcomes in those initiated on SGLT2i versus other glucose-lowering drugs (oGLDs) across 6 countries in the Asia Pacific, the Middle East, and North American regions. In Korea, 336,644 episodes of initiation in SGLT2i or oGLD group between September 2014 and December 2016 were identified in Korea National Health Insurance database after propensity score matching. SGLT2i users was associated with a lower risk of all-cause death (hazard ratio [HR], 0.72; 95% confidence interval [CI], 0.67~0.77), hospitalization for heart failure (HHF) (HR, 0.87; 95% CI, 0.82~0.92), all-cause death or HHF (HR, 0.81; 95% CI, 0.78~0.85), myocardial infarction (HR, 0.81; 95% CI, 0.74~0.89), and stroke (HR, 0.82; 95% CI, 0.78~0.86) compared with oGLD users. In conclusion, initiation of SGLT2i had a lower risk of cardiovascular events in people with type 2 diabetes compared with oGLDs.

導赤散이 白鼠 腎臟機能에 미치는 影響 (Effects of Dojuksan on the Renal Function in Rats)

  • 윤현자;윤용갑;강순수
    • 한방안이비인후피부과학회지
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    • 제12권2호
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    • pp.53-66
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    • 1999
  • This study has been carried out to investigate the effects of Dojuksan on the renal functions and internal secretion system, as water balance, urine volume, urinary excretion of sodium and potassium, free water clearance, urinary excretion of creatinine, plasma levels of artrial natriuretic peptide (ANP), plasma levels of aldosterone and plasma renin activity, comparing experimental group which Dojuksan water extract were administrated with control group. Sprague-Dawley rats, about 200-250 g, were used for this experiment. The results of this study were as follows: 1. Water balance decreased significantly after the administration of Dojuksan water extract. 2. Urine volume increased significantly after the administration of $100{\mu}l$ Dojuksan water extract per 100g rat. 3. Urinary excretion of sodium increased significantly but urinary excretion of potassium did not change after the administration of Dojuksan water extract. 4. Free water clearance decreased significantly after the administration of Dojuksan water extract 5. Urinary excretion of creatinine increased significantly after the administration of Dojuksan water extract 6. Plasma renin activity did not change after the administration of Dojuksan water extract 7. Plasma levels of artrial natriuretic peptide (ANP) did not change after the administration of Dojuksan water extract 8. Plasma levels of aldosterone decreased significantly after the administration of 200 ${\mu}Dojuksan water extract per l00g rat The results suggest that Dojuksan increase the urinary excretion of sodium. and thus reduce the water balance, which resulted from suppression of sodium reabsorption into renal tubule by increasing glomerular filtration rate and decreasing aldosterone.

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Isoflavones Extracted from Sophorae fructus Upregulate IGF-1 and TGF-$\beta$ and Inhibit Osteoclastogenesis in Rat Born Marrow Cells

  • Joo, Seong-Soo;Won, Tae-Joon;Kang, Hee-Cheol;Lee, Do-Ik
    • Archives of Pharmacal Research
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    • 제27권1호
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    • pp.99-105
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    • 2004
  • Isoflavones have been a central subject in research on the natural phytoestrogens found in Leguminosae. Their effects on bone formation and remodeling are important in that they can act like estrogen by binding on estrogen receptors on the target cell surface. We, therefore, believed that isoflavones may help in the treatment of patients with estrogen deficiency disease such as estrogen replacement therapy (ERT) for osteoporosis. As commonly known, osteoporosis is one of the hormonal deficiency diseases, especially in menopausal women. When estrogen is no longer produced in the body a remarkable bone remodeling process occurs, and the associated events are regulated by growth factors in the osteoblast lineage. In the present study, we investigated whether isoflavones (Isocal) extracted from Sophorae fructus affect the growth factors IGF-I and TGF-$\beta$ that have been known to be related with bone formation. In the study, we found that the active control (PIII) effectively enhanced the level of nitric oxide (NO) and growth factors, and thereby inhibited osteoclastogenesis. The most efficient concentration was $10^{-8}$% within five days, whereas the comparative control (soybean isoflavone) was not as effective even at a lower concentration. In conclusion, the products which contain enriched glucosidic isoflavone and nutrient supplements such as shark cartilage and calcium can be used for osteoporosis therapy by enhancing the production of IGF-I and TGF-$\beta$. Furthermore, the NO produced through endothelial constitutive NO synthase (ecNOS) may playa role in inhibiting bone reabsorption.

鷄胎賢의 Alkaline Phosphatase, PAS-陽性物質 및 燐脂質의 分布에 관하여 (Distribution of Alkaline Phosphatase, PAS-Positive Materials and Phospholipid in the Kidney of the Developing Chick)

  • 하재청
    • 한국동물학회지
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    • 제12권3호
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    • pp.77-84
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    • 1969
  • 著者는 白色레그혼의 種卵을 孵化시켜 얻은 鷄胎中 賢과 後賢에 있어서의 alk. p., PAS-陽性物質 및 燐脂質의 消長과 局在位置의 變異를 組織化學的 方法으로 追究하여 다음과 같은 結果를 얻었다. 1. 分泌尿細管의 器官形成에 앞서 未分化 間葉組織內에 强한 alk. p. 活性이 出現하였으며 同活性은 分泌尿細管의 分化와 함께 消失하였다. 2. 中賢 및 後賢 分泌尿細管의 分化와 함께 alk. p. 및 PAS-陽性物質은 分泌尿細管의 刷子綠에 强陽性反應을 보였다. 3. 中賢 및 後賢 分泌尿細管의 細胞質과 刷子綠은 强한 燐脂質 陽性反應을 띠었다. 4. 造賢組織의 分化中 未分化 間葉組織에 alk. p. 活性이 出現하였다가 組織의 分化와 함께 消失된 事實에서 보아 alk. p. 는 組織分化에 關與하는 것으로 생각된다. 5. 中賢 및 後賢 分泌尿細管의 刷子  에 있어서 alk. p. 와 PAS-陽性物質 및 燐脂質의 變異와 分布狀態가 一致한 것으로 보아 alk. p. 는 炭水化物의 再吸收 및 燐脂質代謝에 關與하는 것으로 思料된다.

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염전의 함수로 제조한 천일식제조소금의 물리화학적 특성 (The Physical and Chemical Properties of Salt Manufactured by New Process with Brine Produced in Korean Salt-farms)

  • 김경미;김인철
    • 한국식품영양과학회지
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    • 제42권10호
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    • pp.1664-1672
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    • 2013
  • 천일염은 자연 환경에서 제조되기 때문에 불용분 사분과 같은 이물이 함유될 가능성이 있다. 본 연구는 여과와 증발을 통하여 소금의 불순물 등 이물질을 효율적으로 제거하면서도 미네랄이 풍부한 소금을 생산하기 위해 수행되었다. 함수를 여과한 후 $90^{\circ}C$에서 회전식진공농축기를 이용하여 소금결정을 제조한 후에 탈수하였다. 이렇게 제조된 소금을 천일식제조소금이라 명명하였다. 소금의 수율은 물의 증발량에 의해 결정되는데, 증발량이 40%, 50%, 60%일 때 각각 40S, 50S, 60S로 표기하였다. 천일식제조소금의 수율은 40S, 50S, 60S가 각각 7.22%, 10.79%, 15.06%로 일반 천일염의 제조 수율인 4~8%보다 유사하거나 높았다. 천일식제조소금의 염도는 40S, 50S, 60S가 각각 90.38%, 91.16%, 68.16%를 나타냈다. 관능검사 결과 전체기호도가 가장 높은 소금은 40S이며, 쓴맛이 강함 소금은 60S를 나타냈다. Na, Mg, K, Ca의 미네랄 함량은 40S와 50S가 Mg 함량이 낮다는 것을 제외하면 천일염과 유사하였다. 불용분 함량은 천일염이 0.023%로 천일식제조소금보다 높고, 사분분석 함량은 천일염과 40S, 50S는 유의차가 없었다. 용해속도(g of salt/100 mL $H_2O$/sec)는 40S, 50S, 60S가 각각 0.69, 0.70, 0.69로 천일염의 용해속도(0.47)보다 높았고, 상대습도 70%, 저장온도 $20^{\circ}C$에서의 수분 재흡수 속도는 천일식제조소금 40S, 50S가 정제염보다는 빠르지만 천일염보다는 약 3~5배 낮은 결과를 보여주었다. 본 연구에서 개발한 천일식제조소금은 미네랄, 불순물 함량, 용해속도 및 수분 재흡수 등의 물리화학적 특성이 천일염에 비해 우수한 것으로 판단된다.

Effects of Supplemental Recombinant Bovine Somatotropin (rbST) and Cooling with Misters and Fans on Renal Function in Relation to Regulation of Body Fluids in Different Stages of Lactation in Crossbred Holstein Cattle

  • Boonsanit, D.;Chanpongsang, S.;Chaiyabutr, N.
    • Asian-Australasian Journal of Animal Sciences
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    • 제23권3호
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    • pp.355-365
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    • 2010
  • The aim of this study was to investigate the effect of supplemental recombinant bovine somatotropin (rbST) and cooling with misters and fans on renal function in relation to regulation of body fluids in different stages of lactation in crossbred Holstein cattle. Ten, 87.5% crossbred Holstein cattle were divided into two groups of 5 animals each, housing in a normal shaded barn (NS) and in a shaded barn with a mister-fans cooling system (MF). The experiment in each group was divided into 3 phases, early- (Day 75 postpartum), mid- (Day 135 postpartum), and late stage of lactation (Day 195 postpartum). The pre-treatment study was conducted on the starting day of each stage of lactation and the treatment study was performed after the end of the pre-treatment, during which the animal was injected with 500 mg of rbST (POSILAC) every 14 days for three times. During the study, ambient temperature at the hottest period daily in the MF barn was significantly lower, while relative humidity was higher than that of the NS barn. The temperature humidity index (THI) in both barns ranged from 79-85 throughout the periods of study. Cows in the MF barn showed a lower rectal temperature and respiration rate as compared with cows in the NS barn. The effect of rbST administration increased both rectal temperature and respiration rates of cows housed in either the NS or MF barn. Milk yield significantly increased in cows treated with rbST in all stages of lactation. Increases in mammary blood flow, accompanied by increases of total body water (TBW), extracellular fluid (ECF), blood volume (BV) and plasma volume (PV), were observed in both groups of cows receiving rbST in all stages of lactation. No alterations of renal blood flow and glomerular filtration rate were observed in cows receiving rbST, but decreases in urinary excretion and fractional excretion of sodium, potassium and chloride ions appeared to correlate with reduction in the rate of urine flow and osmolar clearance during rbST administration. These results suggest that the effect of rbST supplementation to cows housed either in NS or MF barns on body fluid volume expansion is attributable to changes in the rate of electrolyte excretion by the kidney. The increased availability of renal tubular reabsorption of sodium, potassium and chloride ions during rbST treatment was a major factor in retaining body water through its colligative properties in exerting formation of an osmotic force mechanism.

Mn4+ 도핑된 형광체, Sr1-xBaxGe4O9:MnMn4+0.005 (0.00 ≤ x ≤ 1.00)의 Color Tuning (Color Tuning of a Mn4+ Doped Phosphor : Sr1-xBaxGe4O9:MnMn4+0.005 (0.00 ≤ x ≤ 1.00))

  • 박운배
    • 대한화학회지
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    • 제61권4호
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    • pp.163-167
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    • 2017
  • 백색 LED 기술이 발달함에 따라 적색 형광체는 산업 및 학계에서 점차 중요성이 커지고 있으며, 시장에서 수요는 꾸준히 증가했다. 적색 형광체는 고효율 및 고연색의 LED 조명에 사용된다. 그러나 $Eu^{2+}$ 활성제를 사용한 적색 형광체는 4f-5d 전이로 발생하는 녹색 또는 황색 스펙트럼 영역에서의 강한 재흡수로 인해 백색 LED 칩에서 색상 변경 및 발광 강도의 저하를 유발했다. 이러한 단점이 없고 연색성 지수(CRI)를 더 향상할 수 있는 $Mn^{4+}$ 도핑된 형광체가 현재 매우 중요하다. 그러나 $Mn^{4+}$ 도핑된 형광체는 $^2E_g{\rightarrow}^4A_2$ 전이로 인하여 발광 파장이 모체에 따라 결정된다는 단점이 있다. 본 연구는 동일구조의 $SrGe_4O_9$$BaGe_4O_9$ 모체를 합성하여 $Sr_{1-x}B_axGe_4O_9:Mn^{4+}{_{0.005}}$ (x = 0, 0.25, 0.5, 0.75 and 1)를 얻었다. 이로 인해 LED 기술의 다양한 색상 조정이 가능해졌다.

가토신장기능에 미치는 뇌실내 Ketanserin의 영향 (Influence of Intracerebroventricular Ketanserin on Rabbit Renal Function)

  • 국영종;김경근;임영채;김유남;국훈
    • 대한약리학회지
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    • 제26권2호
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    • pp.153-160
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    • 1990
  • 5-Hydroxytryptamine(5-HT)를 가토뇌실내로 투여 (icv)하면 이뇨와 Na배설증가가 초래되며, 이러한 작용은 $5-HT_1$ 수용체길항제인 methysergide에 의하여 차단되므로 중추성 신장기능조절에 있어 중추 tryptamine계의 관련이 시사된 바 있다. 본 연구에서는 $5-HT_2$ 길항제로 알려진 ketanserin (KET)를 이용하여 $5-HT_2$ 수용체의 역할을 구명하고자 하였다. KET $120\;{\mu}g(=0.3{\mu}moles)/kg$ icv는 신혈류역학에는 아무런 변동을 일으키지않으나 유의한 Na배설증가를 초래하여, 세뇨관에서의 Na 재흡수 감소가 시사되었다. 전신혈압은 약간 감소하였다. 정맥내 투여시에는 유의한 기능변동을 볼 수 없었다. 5-HT $200{\mu}g/kg$ icv는 경미하나 유의한 Na배설증가 및 이뇨작용을 나타냈다. 그러나 신장기능에 그다지 큰 영향을 미치지 않는 양인 $40{\mu}g/kg$의 KET icv후에는 5-HT의 작용이 크게 강화되어, Na배설분획이 9.3%에 달하였다. Norepinephrine, dopamine, histamine과 같은 다른 생체아민의 신장작용은 KET전처치에 의하여 영향받지 아니하였다. 본 연구는 중추 $5-HT_1$ 수용체와는 반대로 중추 $5-HT_2$ 수용체는 항이뇨 및 Na배설감소를 매개하고 있으며, 중추 tryptamine계는 신장기능을 이중적으로 조절하고 있음을 시사하였다.

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