• Title/Summary/Keyword: Reabsorption

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Regulation of AQP-4 Water Channel Expression in the Brain during Development and by Ischemia

  • Jung, Jin-Sup;Kim, Hae-Gyu;Bae, Hae-Rahn;Suh, Duk-Joon;Park, Hwan-Tae;Lee, Sang-Ho
    • The Korean Journal of Physiology and Pharmacology
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    • v.1 no.5
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    • pp.495-504
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    • 1997
  • Water transport is mediated by two distinct pathways, diffusional and channel-mediated water transport. The first molecular water channel was identified from human erythrocytes in 1992. Genetically-related proteins from other mammalian tissues have subsequently been identified to transport water, and the group is referred to as th "Aquaporins". Aquaporin-4 (AQP4) is most abundant in the brain, which may be involved in CSF reabsorption and osmoregulation. However, ontogeny and regulatory mechanisms of AQP4 channels have not been reported. Northern blot analysis showed that AQP4 mRNA began to be expressed in the brain just before birth and that its expression gradually increased by PN7 and then decreased at adult level. AQP4 was expressed predominantly in the ependymal cells of ventricles in newborn rats. And then its expression decreased in ependymal cells and increased gradually in other regions including supraoptic and paraventricular nuclei. AQP4 is also expressed in the subfornical organ, in which the expression level is not changed after birth. Cryogenic brain injury did not affect expression of AQP4 mRNA, while ischemic brain injury decreased it. Osmotic water permeability of AQP4 channel expressed in Xenopus oocytes was inhibited by the pretreatment of BAPTA/AM and calmidazolium, a $Ca^{2+}/Calmodulin$ kinase inhibitor, in a dose-dependent manner. These results indicate that the expression and the function of AQP4 channel are regulated by developmental processes and various pathophysiological conditions. These results will contribute to the understanding of fluid balance in the central nervous system and the osmoregulatory mechanisms of the body.

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Diuretic Action of Vasopressin (바소프레신의 이뇨작용)

  • Go, Seok-Tae;Yun, Jae-Gyeong;Yu, Gang-Jun
    • YAKHAK HOEJI
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    • v.40 no.4
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    • pp.468-477
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    • 1996
  • Vasopressin which is an antidiuretic hormone in human body produced the diuretic action in dog. This study was investigated in order to certify the diuretic action and to search out the mechanism of the action on the vasopressin. Vasopressin, when given in a dose of 10.0mU/kg, bolus+1.0mU/kg/min intravenously, exhibited the increase of urine flow(Vol), renal plasma flow(RPF), osmolar clearance (Cosm) and amounts of sodium and potassium excreted in urine ($E_{Na},\;E_K$), the decrease of reabsorption rate of sodium and potassium in renal tubules ($R_{Na},\;R_K$), and then elevated the mean arterial pressure(MAP). Vasopressin given in a increased dose to 30.0mU/kg, bolus+1.0mU/kg/min intravenously elicited the same aspect with that exhibited by a small dose in changes of Vol. and all renal function and potentiated the change rates, whereas this time MAP did not change at all when compared with control value. Vasopressin, when administered into a renal artery, did not induce the changes of Vol and all renal function in experimental (administered) kidney, but increased slightly the Vol, glomerular filtration rate(GFR), $E_{Na},\;and\;E_K$ expected the no change of $R_{Na}\;and\;R_K$ in the control (not administered) kidney. Vasopressin, when infused into carotid artery, showed the increase of Vol. GFR, $E_{Na},\;and\;E_K$ and no change of $R_{Na}\;and\;R_K$ in a dose of 1/5 of intravenous dose. Diuretic action of vasopressin administered into carotid artery was not influenced by renal denervation. Above results suggest that vasopressin produced diuretic action by hemodynamic changes in dogs. These hemodynamic changes may be mediated by central endogenous substances not associated with renal nerve.

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The Possible Modification of the Half Life of the $^{133}Cs$ nucleus in the Finite Space (유한한 공간에서 $^{133}Cs$ 원자핵 반감기의 변화에 대한 연구)

  • Jeong, Moon-Taeg;Dong, Kyung-Rae
    • Journal of radiological science and technology
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    • v.32 no.2
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    • pp.213-218
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    • 2009
  • A theoretical investigation has been carried out on how the energy width of the excited state of the nuclei is modulated when the $\gamma$-ray source is placed between two gold plates, at the center of the gold cylinder or the sphere. The width of the 81-keV level of $^{133}Cs$ is shown to become narrower by 3.7% at 4.2 K by reabsorption of $\gamma$ rays scattered backward from the parallel plates which are made of a 0.05-cm-thick, 3-cm-radius gold plates and separated from each other by 1.0 mm. With a 0.05-cm-thick, 5-cm-long, 1.0-mm-radius gold cylinder, we found that a width became narrower by 6.5%. In addition, when the nuclei is located in a spherical reflector of 1.0 mm in radius made of gold with a thickness of 0.5 mm. the level width is reduced by about 18.2% at a temperature 4.2 K. The results of this study indicates that the life-time of energy level was prolonged.

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HYPOPHOSPHATEMIA RICKETS : A CASE REPORT (Hypophosphatemia rickets 환아의 증례보고)

  • Yang, Kyu-Ho;Choi, Nam-Ki;Kim, Seon-Mi;Jung, Hee-Kyoung
    • Journal of the korean academy of Pediatric Dentistry
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    • v.32 no.1
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    • pp.152-157
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    • 2005
  • Hypophosphatemia rickets, also known as Vitamin D-resistant rickets(VDRR) and refractory rickets, is a form of rickets which is resistant to the usual doses of vitamin D. VDRR is characterized by decreased renal tubular reabsorption of inorganic phosphate and is easily diagnosed by a normal blood calcium, hypophosphatemia, and slightly elevated alkaline phosphatase. Clinical features of Hypophosphatemia rickets included lateral bowing deformities of the legs, short stature, scoliosis, and enlargement of wrist and ankles. Dental finding in patient with VDRR were spontaneous dental abscesses in caries free teeth and other dental findings included delayed eruption, delayed apical closure, thin and hypoplastic enamel, absent or poorly defined lamina dura, enlarged pulp chambers, and numerous accessory canals and pulp horns that extend up and into the dentinoenamel junction. we reported the clinical feature and treatment of VDRR child who was referred from the department of pediatrics for early loss of primary teeth and its treatment.

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Cell-Assisted Lipotransfer for the Treatment of Parry-Romberg Syndrome

  • Castro-Govea, Yanko;De La Garza-Pineda, Oscar;Lara-Arias, Jorge;Chacon-Martinez, Hernan;Mecott-Rivera, Gabriel;Salazar-Lozano, Abel;Valdes-Flores, Everardo
    • Archives of Plastic Surgery
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    • v.39 no.6
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    • pp.659-662
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    • 2012
  • Progressive facial hemiatrophy, also known as Parry-Romberg syndrome, is a progressive and self-limited deformation of the subcutaneous tissue volume on one side of the face that creates craniofacial asymmetry. We present the case of a patient with a five-year history of progressive right facial hemiatrophy, who underwent facial volumetric restoration using cell-assisted lipotransfer (CAL), which consists of an autologous fat graft enriched with adipose-derived stem cells (ASCs) extracted from the same patient. ASCs have the capacity to differentiate into adipocytes. They also promote angiogenesis, release angiogenic growth factors, and some can survive as stem cells. The use of autologous fat as a filler in soft tissue atrophy has been satisfactory in patients with mild and moderate Parry-Romberg syndrome. Currently, CAL has showed promising results in the long term by decreasing the rate of fat reabsorption. The permanence and stability of the graft in all the injected areas has showed that autologous fat grafts enriched with stem cells could be a promising technique for the correction of defects caused by this syndrome.

Upconversion Mechanisms in $Tm^{3+}$-doped Glasses under 800 nm Excitation (800nm 파장 여기관에 의한 $Tm^{3+}$첨가 유리내 상향 전이 현상 기구)

  • Jeong, Hoon;Chung, Woon-Jin;Heo, Jong
    • Journal of the Korean Ceramic Society
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    • v.37 no.2
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    • pp.111-116
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    • 2000
  • 700nm red emission(3F3longrightarrow3H6) in Tm3+ ion with 800 nm(3H6longrightarrow3H4) excitation via upconversion process has been reported only in host materials which have low phonon energies such as halide crystals. However, we observed 700nm and 480nm(1G4longrightarrow3H6) upconverted emission with 800nm excitation in several oxide glasses which has never reported. With spectroscopic analyses and lifetime measurements of each nergy level of Tm3+ ion doped in various oxide glasses, following mechanisms are suggested. For red upconversion, upconversion mechanism changed with Tm3+ concentration. While direct excitation up to 3F3 level via anti-Stokes excitation was dominated at low concentration, two-step excitation via 3H6longrightarrow3H4 and 3F4longrightarrow3F3 transitions was dominated at high concentration. For blue upconversion, two step excitation mechanism up to 1G4 level was suggested as follows : electrons are exciated up to 3H5 with direct excitation with pumping light up to 3H4 followed by multiphonon relaxation, and then additional reabsorption of pumping light excites electrons up to 1G4.

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Effects of Dietary Rna and Adenine on Feed Intake and Kidney Weight and Function in Adult Cockerels

  • Kubota, T.;Karasawa, Yutaka
    • Asian-Australasian Journal of Animal Sciences
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    • v.10 no.3
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    • pp.260-264
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    • 1997
  • This study was conducted with adult cockerels to determine whether dietary RNA affects feed intake and renal weight and function, and if the responses are similar to dietary adenine. Chickens were ad libitum fed a RNA diet (100 g/kg) or an adenine diet (9.1 g/kg) for 14 d and catheterized in right jugular vein, hepatic portal vein and both urethers, and saline together with para-amino hippuric acid and sodium thiosulfate was continuously infused into them to evaluate renal functions. Dietary RNA reduced feed intake and body weight, and dietary adenine increased kidney weight expressed as a proportion of body weight (P < 0.05). Feed intake and body weight on the adenine diet and kidney weight on the RNA diet showed similar though non significant tendencies. No calculi were detected in the kidney in chickens fed either the RNA or adenine diets. Plasma inorganic phosphate (IP), Ca and 1,25 $(OH)_2$ vitamin $D_3$ concentrations were increased by dietary RNA and adenine, although the increases of IP and Ca in adenine-fed chickens were not significant. Uric acid and urea concentrations in the blood plasma were unaffected by dietary RNA or adenine. Both dietary RNA and adenine increased renal blood flow rates 3.5-3.7 fold, renal plasma flow rates 3.4-3.7 fold and glomerular filtration rates (GFR) 2.9-3.0 fold (p < 0.01). Clearance of urea, IP and Ca were also enhanced by dietary RNA, but not by dietary adenine. However, neither RNA nor adenine affected uric acid clearance. Only IP clearance was significantly augmented at the glomerular level by dietary RNA (p < 0.05). Glomerular filtration of uric acid, urea, IP and Ca and reabsorption of urea, IP and Ca at the renal tubule were increased by dietary RNA and adenine (p < 0.05), whereas tubular secretion of uric acid was decreased by both dietary treatments. It is concluded that dietary adenine is effective in changing renal function and P and Ca metabolism in chickens.

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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Study on Kidney Toxicities of WK-38 for Treatment Vascular Diseases in Rats (혈관질환 억제 효능이 있는 WK-38의 백서 신장 독성연구)

  • Kim, Eun-Ju;Lee, An-Sook;Shin, Sun;Kim, Sung-Yeon;Chang, Bo-Yoon;Lee, Ho-Sub;Kang, Dae-Gill
    • Herbal Formula Science
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    • v.17 no.2
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    • pp.187-194
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    • 2009
  • The kidney toxicities of WK-38 used for improvement of the vascular diseases, was examined using male and female Sprague-Dawley rats. The male and female rats were divided into 4 groups for intragastrical treatment with doses of 0, 5, 50, and 500 mg/kg/day for 13 weeks, respectively. In all male and female rats treated with WK-38, no mortality and gross pathological findings were shown for 13 weeks. There was substantially no change in body weight in all rats with treatment of WK-38. Urine osmolality as renal functional parameters were not exchanged in all rats treated with WK-38. The renal functional parameters including electrolytes excretory rate, creatinine clearance, and solute-free water reabsorption were significantly augmented on account of increase in urinary volume in female rats treated with WK-38, but not male. In summary, this study demonstrates that WK-38 exhibits no toxicity on kidney in all male and female rats.

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Effect of Probenecid on Urate Excretion in the Cat Kidney

  • Jung, Dong-Keun;Kim, Yong-Keun;Jung, Jin-Sup;Lee, Sang-Ho
    • The Korean Journal of Physiology
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    • v.25 no.1
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    • pp.37-48
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    • 1991
  • The characteristics of probenecid effect on renal urate excretion in the cat were studied by clearance method and compared with those in the rabbit. In the cat GFR was $3.03{\pm}0.09\;ml/min{\cdot}kg$, and endogenous plasma urate concentration was $1.12{\pm}0.57\;{\mu}g/ml$, which is less than that in the rabbit $(3.33{\pm}0.46\;{\mu}g/ml)$. In the rabbit, $FE_{ur}$ was $1.76{\pm}0.08$ and net urate secretion was observed, while, in the cat $FE_{ur}$ was $0.70{\pm}0.02$ and net reabsorption was observed. In the cat $FE_{ur}$ was dependent on urine flow and independent of plasma urate concentration. In the rabbit $FE_{ur}$ was suppressed by infusion of probenecid $(30\;mg/kg\;-0.6\;mg/kg{\cdot}min)$ into femoral vein. In the cat the same dose of probenecid increased $FE_{ur}$ and concomitantly increased urine flow. Thus, an increase in $FE_{ur}$ by probenecid could be considered to be resulted from a change in urine flow. In the cat infusion of probenecid $(2.5\;mg/kg{\cdot}min)$ into renal artery markedly suppressed $FE_{P\;A\;H}$, but the effects on $FE_{ur}$ and urine flow were similar to those when probenecid was infused into femoral vein. These results indicate that in the cat kidney urate filtered through glomerulus is reabsorbed by a probenecid-insensitive mechanism with no evidence for net secretion.

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