• Title/Summary/Keyword: tubular reabsorption

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Effect of Salviae Radix on Cell Death and DNA Damage in Renal Proximal Tubular Cells Exposed to $H_2O_2$ ($H_2O_2$에 노출된 신장 근위 세뇨관 세포에서의 세포 사망 및 DNA 손상에 대한 단삼의 효과)

  • Sung-Dae, Kim;Ji-Cheon, Jeong
    • The Journal of Korean Medicine
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    • v.22 no.3
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    • pp.21-30
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    • 2001
  • 목적 : 이전 연구에서 단삼 추출액이 강력한 항산화 작용이 있음을 확인한 바 있어 단삼 추출액이 신장세뇨관 세포에서 oxidant에 의한 세포사망 및 DNA 손상을 방지하는 지를 조사하고 이러한 효과가 지질의 과산화를 억제하는 효과에 기인하는 지를 시험하였다. 방법 : 신장 근위세뇨관 세포 유래 세포주인 opossum kidney (OK)세포를 이용하여 세포 사망은 frypan blue exclusion방법을 이용하여 평가하였고, DNA손상 정도는 double stranded DNA의 파괴를 측정하여 평가하였다. Oxidant 약물 모델로는 $H_2O_2$를 사용하였다. 결과 : $H_2O_2$는 적용시 간과 농도에 비례하여 세포 사망을 유도하였다. 단삼 추출액은 0.05% 농도에서 $H_2O_2$에 의한 세포사망 및 DNA 손상을 방지하였다. 이러한 방지효과는 $H_2O_2$ 제거 효소인 catalase와 철 착염제인 deferoxamine에 의해서도 나타났다. 그러나 강력한 항산화제인 DPPD는 $H_2O_2$에 의한 세포 사망이나 DNA손상을 방지하지 못하였다. $H_2O_2$는 세포내 ATP 농도를 감소시켰으며. 이러한 감소는 poly (ADP-ribose) polymerase억제제인 3-aminobenzamide에 의해 방지되었으나 단삼 추출액에 의해서는 영향을 받지 않았다. 3-aminobenzamide는 $H_2O_2$에 의한 세포 사망을 방지하였다. $H_2O_2$는 지질의 과산화를 증가시켰으며, 이러한 변화는 단삼 추출액과 DPPD에 의해 방지되었다 결론 : OK 세포에서 $H_2O_2$에 의한 세포사망과 DNA 손상에는 지질의 과산화가 중요한 역할을 하지 않으며, 단삼 추출액의 $H_2O_2$에 의한 세포 사망과 DNA 손상 방지 효과는 항산화 작용이 아닌 다른 기전에 기인하는 것으로 사료된다.

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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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    • v.4 no.1
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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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Effects of the Saponin of Polygalae Radix on the Renal Function and CNS-Depression (원지(遠志) Saponin의 이뇨효과(利尿效果) 및 중추억제작용(中樞抑制作用)에 관한 연구(硏究))

  • Park, Dai-Kyu;Lee, Wan-Ha
    • Korean Journal of Pharmacognosy
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    • v.14 no.4
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    • pp.178-192
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    • 1983
  • Polygalae Radix was used as diuretics, analgesics and expertorants in oriental medicine. The root of Polygala tenuifolia Willd. (Polygalaceae) is comprised saponin (Onjisaponin A,B,C,D,E,F and G) polygalitol, onsitin and sugars. The pharmacological action of crude Polygala-saponin (PS) obtained from the roots are studied. The following results were obtained; 1) The median lethal dose $(LD_{50})$ of PS in mice is presented 71.1mg/kg s.c. and 694. 5mg/kg p.o.. 2) PS demonstrated diuretic action of relatively long acting duration in mice. 3) The diuretic mechanism of PS was found due to inhibitory effect of renal tubular reabsorption of electrolytes and glomerular vascular dilatation. 4) The group, administered simultaneously PS and cefadroxil monobydrate was significantly increased with PS alone group on diuretic action. Synergistic effect cefadroxil monohydrate on the diuretic action of PS seems due to competitive inhibition of plasma protein binding with PS. 5) PS demonstrated analgesic action by the acetic acid stimulating method and Randall-Selitto test in mice. 6) PS presented antipyretic action against febrile treated with the typhoid vaccine. 7) PS was significantly prolonged against the hypnotic duration of pentobarbital in mice. 8) Onset time convulsion and death induced by picrotoxin and strychnine in mice were not delayed. According to the above results, the PS was identified as a pharmacological active component obtained from roots of Polygala tenuifolia Willd.

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Renal Handling of Sodium and Potassium in Cadmium Exposed Rats

  • Kim, Yung-Kyu;Park, Yang-Saeng
    • The Korean Journal of Physiology and Pharmacology
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    • v.2 no.4
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    • pp.503-510
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    • 1998
  • Effects of cadmium exposure on renal $Na^+$ and $K^+$ transports were studied in rats. During the course of cadmium treatment (2 mg Cd/kg/day, s.c. injections for 3 weeks) renal tubular transports of $Na^+$ and $K^+$ were evaluated by lithium clearance technique. During the early phase (first week) of cadmium treatment, urinary $Na^+$ excretion decreased drastically and this was due to an increased $Na^+$ reabsorption both in the proximal and distal nephrons. During the late phase (third week) of cadmium treatment, filtered $Na^+$ load was decreased by reduction in GFR, but the renal $Na^+$ excretion returned to the control level due to impaired $Na^+$ transport in the proximal tubule. Urinary excretion of $K^+$ did not change during the early phase, but it rose markedly during the late phase of cadmium treatment. These results indicate that a light cadmium intoxication induces a $Na^+$ retention, and a heavy intoxication results in a $K^+$ loss. Possible mechanisms for these changes are discussed.

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Development of Specular Reflector Design Algorithm Considering Reflected Light Distribution and Light Absorption by Lamp (반사 배광과 램프에 의한 반사광 흡수를 고려한 경면반사판 설계 알고리즘 개발)

  • Hwang, Jae-San;Lee, Jung-Wook;Kim, Gi-Hoon;Kim, Hoon
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.15 no.1
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    • pp.7-12
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    • 2001
  • Tbis topic is about the development of a 2-dimensional specular reflector design aid software. For a long and cylindrical shaped lamp with perfect diffusing smface, direction and quantity of reflected light flux from a specular reflector strip can be calculated consideJing reabsorption by the lamp itself. Assuming a reflector as a combination of several strip segments, the reflected flux is calculated as position, length and declination of each segment are detennined. At each step, calculated reflected flux distribution and desired flux distribution is compared graphically and numerically, so that roost optimized and efficient reflector shape can be decided by the designer. We think that this software would be useful for designing reflectors for relatively long light sources, such as fluorescent lamp, tubular high pressure sodium lamp, low pressure sodium lamp, and so on. so on.

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Influence of Intracerebroventricular Haloperidol on the Renal Function of the Rabbit (가토신장기능에 미치는 측뇌실내 Haloperidol의 영향)

  • Kim, Joong-Ky;Choi, Bong-Kyu;Kook, Young-Johng
    • The Korean Journal of Pharmacology
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    • v.18 no.2
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    • pp.103-117
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    • 1982
  • In an effort to provide evidence as to the regulatory role of the central dopaminergic system on the renal function, the effects of centrally administered dopamine and its specific antagonist haloperidol were investigated. Haloperidol (HA) given intracerebroventricularly (i.c.v.) induced antidiuresis in doses of 15 and $50{\mu}g/kg$. With $15{\mu}g/kg$ sodium reabsorption in the tubules was increased, while with $50{\mu}g/kg$ free-water reabsorption was increased. However, a marked diuresis with increased sodium and potassium was observed with $150{\mu}g/kg$. Hemodynamic changes were not evident, indicating that the diuresis is of tubular origin. Dopamine (DA), on the other hand, produced antidiuresis when given i.c.v. in a dose-related fashion. With smaller doses of 5 and $15{\mu}g/kg$ the antidiuresis was related to increased reabsorption of sodium in the tubules, but higher doses of 50 and $150{\mu}g/kg$ the decreases in renal blood flow and glomerular filtration rate were evident in addition to the tubular action. After pretreatment with $150{\mu}g/kg$ HA, the effects of $15{\mu}g/kg$ DA was abolished, but the antidiuretic actions of 50 and $150{\mu}g/kg$ were not blocked, and the natriuretic diuretic action of HA was overcome and became inconspicuous. These observations indicate that the central dopaminergic system influences the renal function by producing antidiuresis, and HA elicits diuresis and natriuresis by competitively antagonizing DA specifically on the central dopaminegic receptors. The antidiuresis observed with smaller doses of HA can be best explained by the facts that there are more than two types of DA-receptors in the brain and that the presynaptic autoreceptors on the dopaminergic neurones which affect the dopamine release at the synapse are more sensitive than the postsynaptic receptors. Overall, these data provide an evidence indicating that the central dopaminergic system plays a role in the regulation of renal function in the rabbit.

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A Case of Proximal Renal Tubular Acidosis Accompanied by Vitamin D Deficient Rickets (비타민 D 결핍성 구루병에 동반된 근위 신 세뇨관성 산증 1례)

  • Kwon Seung-Yeon;Choi Youn-Jung;Kim Kee-Hyuck
    • Childhood Kidney Diseases
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    • v.10 no.1
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    • pp.58-64
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    • 2006
  • In the clinical state of vitamin D deficiency, it is possible that associated phosphate depletion, parathyroid hormone excess, and hypocalcemia may all depress the proximal tubular reabsorption of bicarbonate, in addition to abnormal skeletal modeling or remodeling, Although nutritional rickets is considered a rare disease in developed countries nowadays, cases of vitamin D deficient rickets caused by various unhealthy lifestyles such as insufficient exposure to sunlight, breast feeding infants without giving vitamin D supplements, unbalanced vegetarian diets of breast feeding mothers, low-birth weight, and maternal deficiency of vitamin D or calcium are increasing. Here, we present the case of an 8 month old girl, who was completely breastfed without any weaning diet or infant vitamin supplements. She visited our emergency room with hypocalcemic seizure and subsequently was diagnosed with vitamin D deficient rickets accompanied by overt bone changes and proximal renal lobular acidosis. After intravenous(IV) and oral calcium replacement therapy(IV calcium gluconate injection 1 mEq/kg/day for 6 days, 2 mEq/kg/day for 4 days followed by oral calcium gluconate administration 4 g/day for 3 days) with vitamin D supplement(Alfacalcidol 0.5 mcg/day) during admission, serum calcium level was normalized with clinical improvement. Oral sodium bicarbonate(0.6 g/day) was administered from the $2^{nd}$ hospital day for 2 weeks, which normalized the serum bicarbonate(measured by $tCO_2$) level. Calcium and vitamin D replacement were continued for 2 weeks and 3 months each. After discontinuing medications, follow up laboratory findings showed good maintenance of serum calcium, alkaline phosphate and bicarbonate levels with complete improvement of bone X-ray findings.

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Effect of thyroparathyroidectomy on urinary excretion of sodium, potassium, calcium and phosphate in the rabbits (갑상선 부갑상선 적출이 뇨중 Na, K, Ca 및 $PO_4$ 배설에 미치는 영향)

  • Choi, Duck-Kyung
    • The Korean Journal of Physiology
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    • v.16 no.1
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    • pp.69-76
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    • 1982
  • The effect of parathyroid hormone on calcium and phosphate metabolism have been widely investigated, however less attention has been paid to the effect on urinary excretion. This study was performed for the purpose determining urinary excretion of Na, K, Ca, and $Po_4$, of 18 thyroparathyroidectomized (TPTX) rabbits, which were TPTX previously 7 to 10 days compared with the same normal ones. After TPTX 0.2 mg/day of synthyroid was donated to the rabbits. The concentration of electrolytes in the serum and urine was determined by the following method; Na and K were determined by means of flame photometry, Ca was by EDTA titration $method^{19)}$, and $Po_4$ by Fiske and Subba-Raw $method^{20)}$. The results as follows. The concentrations of electrolytes in the serum were 1) In the normal control rabbits (N = 25) (data, $Mean{\pm}S.E.$) $Na\;131.72{\pm}1.33\;mEq/L$, $K\;3.59{\pm}0.28\;mEq/L$, $Ca\;12.58{\pm}0.29\;mg%$, $Po_4\;4.50{\pm}\;0.45mg%$. 2) In the TPTX rabbits(N= 18) $Na\;140.6l{\pm}2.56\;mEq/L$, $K\;3.38{\pm}0.36\;mEq/L$, $Ca\;l2.18{\pm}0.45\;mg%$, $Po_4\;3.92{\pm}\;0.35\;mg%$. There was no significant change between the normal and TPTX rabbits. The concentration of elelctrolytes in the urine were variously changed. 3) In the normal rabbits. $Na\;8.40{\pm}1.09\;mEq/L$, $K\;81.59{\pm}10.19\;mEq/L$, $Ca\;16.02{\pm}3.12\;mg%$, $Po_4\;13.16{\pm}2.89mg%$. 4) In the TPTX rabbits, $Na\;14.57{\pm}3.39\;mEq/L$ slight ncreased, $K\;116.06{\pm}12.77\;mEq/L$ significant increased (P<0.05), $Ca\;18.90{\pm}5.44\;mg%$ no significant increased, $Po_4\;43.38{\pm}8.67\;mg%$ significant increased (p<0.01). The effect of TPTX was assumed that it affected upon increasing tubular secretion of $K^+$ and inhibition of the tubular reabsorption of $Po_4$.

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Effects of Euphorbia Pekinensis RUPR. on Rats with Acute Renal Failure induced by Gentamicin Sulfate (대극전탕액(大戟煎湯液)이 Gentamicin sulfate로 유발(誘發)된 백서(白鼠)의 급성(急性) 신부전(腎不全)에 미치는 영향(影響))

  • Lee, Sung-Hyun;An, Se-Yung;Cho, Dong-Hyun;Doo, Ho-Kyung
    • The Journal of Korean Medicine
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    • v.16 no.1 s.29
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    • pp.319-338
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    • 1995
  • This article is to investigate the effects of Euphorbia Pekinensis RUPR. on rats with acute renal failure induced by gentamicin sulfate. So this experimental research was focused on measuring (1)the levels of creatinine, blood urea nitrogen, glutamic oxaloacetic transaminase, glutamic pyruvic transaminase, total protein, sodium, potassium, chloride in the serum and (2)the levels of protein, blood, sodium, potassium, chloride, pH, specific gravity and volume in the urine and (3)intake water. The results were summarized as follows. 1. While the levels of creatinine and glutamic oxaloacetic transaminase, glutamic pyruvic transaminase in the serum were significantly increased, the level of BUN in the serum were partially increased and the levels of sodium and potassium in the serum were partially decreased on the Euphorbia Pekinensis $R_{UPR}$. group. 2. While the urine volume was significantly increased, the levels of protein, blood, sodium and chloride in the urine were partially increased and the specific gravity, pH in the urine were partially decreased. According to the above results, it is shown that Euphorbia Pekinensis $R_{UPR}$. without refinning had a diuretic effect on rats with acute renal failure induced by gentamicin sulfate, but aggravated the glomerular filtration rate and tubular reabsorption. So, it is supposed that Euphorbia Pekinensis $R_{UPR}$. without refinning needs to be used carefully on renal disease and futhermore research about the kinds of extracts form is necessary.

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Studies on the Diuretic Action of Oryeongsan and Kami-Oryeongsan (오령산(五笭散) 및 가미오령산(加味五笭散)이 가토이뇨작용(家兎利尿作用)에 미치는 영향(影響))

  • Lee, Sang-In
    • Korean Journal of Pharmacognosy
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    • v.12 no.1
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    • pp.31-43
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    • 1981
  • In order to determine the effect of Oryeongsan reputed to have diuretic action since Han Dynasty and possible synergetic action of Dianthi Semen, Polygonum avicularis Herba, Kochiae Fructus and Akebiae Lignum, herbs with similar reputation, when added to the above prescription, their decoction powders were solved into distilled water and injected into rabbits through the ear vein. Upon the treatment, the excretion of sodium, potassium and chloride ion together with urine volume was kinetically determined. At the same time the clearance of plasma creatinine and sodium ion was determined and the following results were obtained. Every experimental group demonstrated diuretic action, though feable, of relatively long duration. The diuretic mechanism in the case of Oryeongsan made up by mixing the seperate extracts of individual components and Oryeongsan(A) plus Dianthi Semen was found to be inhibitory effect of renal tubular reabsorption in contrast to the case of Oryeongsan(A) plus Polygonum avicularis Herba, Kochiae Fructus or Akebiae Lignum in which case the diuretic mechanism was found to be glomerular vascular dilatation. The urinary excretion of potassium ion was increased in the case of Oryeongsan(A) plus Dianthi Semen, Kochiae Fructus of Akebiae Lignum whereas in the other cases no similar change was registered. The diuretic action was most remarkable in the case of Oryeongsan(A) plus Polygonum avicularis Herba followed by Oryeongsan(A) plus Kochiae Fructus, Oryeongsan(A) plus Dianthi Semen, extract mixture of individual component of Oryeongsan, Oryeongsan(A) and Oryeongsan(A) plus Akebiae Lignum decreasing order. The duration of diuretic action was found to be 90 minutes in the case of Oryeongsan and mixture of individual component of Oryeongsan, and 60 minutes in the case of Oryeongsan(A) plus Dianthi Semen, Kochiae Fructus or Akebiae Lignum in contrast to the case of Oryeongsan(A) plus Polygonum avicularis Herba which lasted up to 120 minutes.

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