• Title/Summary/Keyword: Reabsorption

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Influence of Bethanidine on the Renal Function of the Dog (개의 신장 기능에 미치는 Bethanidine의 영향)

  • 고석태
    • YAKHAK HOEJI
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    • v.22 no.3
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    • pp.138-147
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    • 1978
  • Bethanidine, which is known as a sympathetic blocking agent, was injected into the vein of a dog in an attempt to investigate the influence on renal funciton. Bethanidine resulted in an increased urine flow and glomerular filtration rate, and it produced an increase of urinary sodium and potassium excretion and a decrease of reabsorption rate of sodium and potassium in renal tubules, whereas renal plasma flow showed no significant changes. After pretreatment of phentolamine, a specific alpha adrenergic blocking agent, bethanidine did not significantly increase glomerular filtration rate and diuresis, significantly increased urinary sodium and potassium excretion although the magnitudes were reduced when compared with that of bethanidine alone. In conclusion, bethanidine-induced diuresis appears to be the result of an inhibited tubuler reabsorpting of electrolytes within the kidney through its sympathetic blockade of renal nerves and of an increased glomerular filtration rate, which was caused by the constriction of vas efferense in the glomeruli.

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Effect of Ketanserin on Renal Function in Dogs (개의 신장기능에 미치는 Ketanserin의 영향)

  • 고석태;심기정;정경희
    • YAKHAK HOEJI
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    • v.43 no.5
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    • pp.665-673
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    • 1999
  • This study was performed in order to investigate the effect of ketanserin, a specific antagonist of 5-HT2 receptor, on renal function in dogs. Ketanserin (50.0 and $150.0{\;}\mu\textrm{g}/kg$), when given intravenously, produced antidiuretic action accompanied with the decreased amounts of sodium and potassium excreted in urine (ENa, EK) and the increased reabsorption rates of sodium and potassium in renal tubules (RNa, RK). Ketanserin (50.0 and $50.0{\;}\mu\textrm{g}/kg$), when administered into a renal artery, elicited antidiuretic action in both experimental and control kidney, this time changes of renal function showed the same aspect as when given intravenously. Ketanserin (15.0 and $50.0{\;}\mu\textrm{g}/kg$) injected into the carotid artery exhibited also antidiuretic action and this antidiuretic action was not affected by renal denervation. Above results suggest that ketanserin elicits antidiuretic through central function, this central antidiuretic action is not mediated by renal nerves.

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Urine Concentrating Mechanism and Urea Transporters (소변 농축 기전과 요소운반체)

  • Kim Dong-Un
    • Childhood Kidney Diseases
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    • v.9 no.1
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    • pp.1-7
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    • 2005
  • The production of concentrated urine is achieved by countercurrent multiplication in the renal medulla. The single effect of the outer medulla is the active NaCl reabsorption in the thick ascending limb, while the single effect of the inner medulla is the passive efflux of NaCl through the thin ascending limb. The passive mechanism in the inner medulla requires a high interstitial urea concentration which is maintained by intrarenal recycling of urea. During the past decade, many transport proteins involved in the urine concentrating mechanism have been cloned, which has enabled us to understand the countercurrent multiplication mechanism on a molecular basis. This review will summarize the locations and functions of the renal medullary transport proteins, and the recent insights that have been acquired into the long term regulation of urea transporters.

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Effect of the Vasectomy on the Fine Structure of the Sperm-Acrosome in Rats (정관절제가 흰쥐의 정자두부의 미세구조에 미치는 영향)

  • Ryoo, Hee-Soo;Kim, Kee-Soo
    • Clinical and Experimental Reproductive Medicine
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    • v.8 no.2
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    • pp.29-33
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    • 1981
  • Vesectomy has been increased as a popular method of birth control because it is simpler than other methods for men. But the vasectomy results in several problems such as relation to effect changes on the structure and function of the reproductive organ. The fate of non-ejaculated spermatozoa is postulated by some authors that those are disappeared by a progress of dissolution and reabsorption in the epididymis, and we have attempted to prove the true state of sperm-acrosome on the fine structure in vasectomized rats. The results were as follows: 1. Apical segments of the acrosome were swollen similar to the shape of club in many spermatozoa. 2. Discontinuities of the outer and inner acrosomal membranes were occasionally noted and there were complete losses of acrosomes in the certain place. 3. There was no evidence of significant changes in the nuclear structure, nor dilatation of the subacrosomal space. 4. Vasectomy might effect destructive changes in the acrosomes of the non-ejaculated spermatozoa in situ.

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Case of hyperosmolar hyperglycemic state by a sodium-glucose cotransporter 2 inhibitor

  • Nho, In-Young;Kim, Hae-Sung;Kang, Nam-Kyu;Lee, Myung-Won;Kim, Soo-Kyung;Park, Seok-O
    • Kosin Medical Journal
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    • v.33 no.3
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    • pp.402-408
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    • 2018
  • Inhibitors of sodium-glucose cotransporters type 2 (SGLT2) are proposed as a novel approach for the management of type 2 diabetes mellitus. SGLT2 cotransporters are responsible for reabsorption of 90 % of the glucose filtered by the kidney. The glucuretic effect resulting from SGLT2 inhibition contributes to reduce hyperglycaemia and also assists weight loss and blood pressure reduction. In this study, we presented the case of a 59-year-old male who developed hyperosmolar hyperglycemic state (HHS), possibly caused by a sodium-glucose cotransporter 2 (SGLT2) inhibitor, a novel class of antihyperglycemic agents. This case highlights that HHS can develop in patients with diabetes treated with SGLT2 inhibitors.

Biodistribition of [$^{125}I$]-labeled biotinylated dendrimer derivatives for antibody pretargeting

  • Kim, Hyung-Sik;Han, Eui-Sik;Wong, Karen J.;Paik, Chang H.
    • Proceedings of the PSK Conference
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    • 2003.10b
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    • pp.99.3-100
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    • 2003
  • It is desirable to improve the tumor targeting and blood clearance pharmacokinetics of radiolabeled monoclonal antibodies. To achieve this goal, several avidin-biotin (Bt) binding systems have been developed to decouple large molecular weight antibodies from small radiolabels, thereby achieving high tumor-to-background radioactivity ratios. We inserted a readily catabolizable linker, triglycine (TG), between 3-[/sup125/I]iodobenzoate and dendrimer (G3). We also neutralized the positive charges of G3 by acylation with tetrafluorophenyl glycolate, thereby blocking proximal tubular reabsorption of G3 mediated by charge attraction. (omitted)

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Simulation and Quasi-linear Theory of Magnetospheric Bernstein Mode Instability

  • Lee, Junggi;Yoon, Peter H.;Hwang, Junga;Choe, Gwang Son
    • The Bulletin of The Korean Astronomical Society
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    • v.44 no.2
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    • pp.70.1-70.1
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    • 2019
  • Multiple-harmonic electron cyclotron emissions, often known in the literature as the (n + 1∕2)fce emissions, are a common occurrence in the magnetosphere. These emissions are often interpreted in terms of the Bernstein mode instability driven by the electron loss cone velocity distribution function. Alternatively, they can be interpreted as quasi-thermal emission of electrostatic fluctuations in magnetized plasmas. The present paper carries out a one-dimensional relativistic electromagnetic particle-in-cell simulation and also employs a reduced quasi-linear kinetic theoretical analysis in order to compare against the simulation. It is found that the Bernstein mode instability is indeed excited by the loss cone distribution of electrons, but the saturation level of the electrostatic mode is quite low, and that the effects of instability on the electrons is rather minimal. This supports the interpretation of multiple-harmonic emission in the context of the spontaneous emission and reabsorption in quasi-thermal magnetized plasma in the magnetosphere.

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CUBN mutation: a benign genetic cause of proteinuria?

  • Hyun Kyung Lee
    • Childhood Kidney Diseases
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    • v.27 no.1
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    • pp.19-25
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    • 2023
  • Proteinuria is an important risk factor for renal and cardiovascular disease. It is associated with a risk for glomerulonephritis, chronic kidney disease, and end-stage renal disease. Therefore, if persistent proteinuria is detected, kidney biopsy is considered to diagnose and treat the underlying disease. Recently, variants in the cubilin (CUBN) gene, which is associated with albuminuria, have been reported. This gene encodes cubilin, a membrane glycoprotein receptor expressed in the renal proximal tubules. Cubilin is a component of the megalin and cubilin-amnionless complex that mediates albumin reabsorption into the proximal tubules through endocytosis. A defect in cubilin leads to a reduction in albumin reuptake, resulting in albumin-dominant proteinuria. Although numerous controversies exist, several reports suggest that cubilin defects lead to proteinuria with a high portion of albuminuria but may not impair renal filtration function. If albuminuria due to reduced cubilin function is confirmed as a benign condition, we can consider using genetic studies to detect CUBN mutations in patients with proteinuria and they may not require any treatment or kidney biopsy. Here, we review recent papers on CUBN mutations and discuss the prognosis and management of individuals with this mutation.

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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Two Cases of Gitelman's Syndrome Diagnosed by Renal Clearance Study (신장청소검사를 이용하여 진단한 Gitelman 증후군 2례)

  • Kim, Tae Hwa;Kim, Seung Jun;Seo, Yu Kyung;Shim, Jung-Yeon;Jung, Hye Lim;Park, Moon Soo;Kum, Dong Hyuk
    • Clinical and Experimental Pediatrics
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    • v.45 no.3
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    • pp.413-417
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    • 2002
  • Gitelman's syndrome is an autosomal recessive disorder characterized by hypokalemic metabolic alkalosis, hypomagnesemia, and hypocalciuria that has recently been reported to be linked to thiazide- sensitive Na-Cl cotransporter gene mutation. In this study, we performed renal clearance studies to differentiate Gitelman's from Bartter's syndrome and to confirm the diagnosis in two patients clinically diagnosed with Gitelman's syndrome. Each patient was hydrated by 20 mL/kg body weight of oral water within 30 minutes, which was followed by intravenous half saline. When urinary flow reached 10 mL/min, samples of urine and serum were obtained to calculate the osmolar clearance, free water clearance, chloride clearance, and distal fractional chloride reabsorption. Subsequently, furosemide or hydrochlorothiazide was administered. Samples were collected and the same parameters were calculated. In our patients, chloride clearance was increased more than 10 times after furosemide administration(2.1 : 25.7 and 2.2 : 27.4 mL/min/100 mL GFR), but not increased after hydrochlorothiazide treatment(2.1 : 1.6 and 2.2 : 2.6 mL/min/100 mL GFR). And the distal fractional chloride reabsorption was significantly decreased by furosemide injection (73% : 15% and 75% : 4.6%), whereas hydrochlorothiazide had no effect on it(73% : 63% and 75% : 78%). These findings indicate that our patients have a defect in thiazide-sensitive Na-Cl cotransporter in the distal tubule, which is compatible with the pathophysiology of Gitelman's syndrome.