• Title/Summary/Keyword: Reabsorption mechanism

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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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Stop-flow Analysis of Urinary Excretion of Sulfadiazine in the Dog (Stop-flow방법(方法)으로 분석(分析)한 sulfadiazine의 요중(尿中) 배설(排泄) 기전(機轉))

  • Ko, Suk-Tai;Lee, Donn-Yil;Kim, Sung-Oh;Kim, Jae-Wan
    • Journal of Pharmaceutical Investigation
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    • v.3 no.4
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    • pp.28-38
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    • 1973
  • The mechanism of urinary excretion of sulfadiazine was investigated in the dogs by means of stop-flow technique Results of experiments were summarized as follows; 1. The ratios of U/P sulfadiazine to U/P creatinine $(U/P_{SD}:U/P_{cr})$ were always lower than 1 in all nephrons, showed a minimum in the proximal area. 2. $U/P_{SD}:U/P_{cr}$ were not affected by Probenecid or 2.4-DNP, whereas increased significantly by administration of sodium bicarbonate. 3. Probenecid did not alter the stop-flow patterns in alkalotic dog too. 4. $C_{SD}$ (clearance of sulfadiazine ) was appreciably influenced by change in urinary PH, or flow rate. All evidences lead to the conclusion that sulfadiazine reabsorption is passively transported by proximal tubules. No clue for active process, either secretory or reabsorptive, was obtained.

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Oocyte Degeneration Associated with Follicle Cells in Female Mactra chinensis (Bivalvia: Mactridae)

  • Kim, Sung Han;Chung, Ee-Yung;Lee, Ki-Young
    • Development and Reproduction
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    • v.18 no.4
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    • pp.321-327
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    • 2014
  • Ultrastructural studies of oocyte degeneration in the oocyte, and the functions of follicle cells during oocyte degeneration are described to clarify the reproductive mechanism on oocyte degeneration of Mactra chinensis using cytological methods. Commonly, the follicle cells are attached to the oocyte. Follicle cells play an important role in oocyte degeneration. In particular, the functions of follicle cells during oocyte degeneration are associated with phagocytosis and the intracellular digestion of products. In this study, morphologically similar degenerated phagosomes (various lysosomes), which were observed in the degenerated oocytes, appeared in the follicle cells. After the spawning of the oocytes, the follicle cells were involved in oocyte degeneration through phagocytosis by phagolysosomes. Therefore, it can be assumed that follicle cells reabsorb phagosomes from degenerated oocytes. In this study, the presence of lipid granules, which occurred from degenerating yolk granules, gradually increased in degenerating oocytes. The function of follicle cells can accumulate reserves of lipid granules and glycogen in the cytoplasm, which can be employed by the vitellogenic oocyte. Based on observations of follicle cells attached to degenerating oocytes after spawning, the follicle cells of this species are involved in the lysosomal induction of oocyte degeneration for the reabsorption of phagosomes (phagolysosomes) in the cytoplasm for nutrient storage, as seen in other bivalves.

Influence of Clonidine on Renal Function of Dogs (Clonidine이 개의 신장기능에 미치는 영향)

  • 고석태;김기환
    • YAKHAK HOEJI
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    • v.27 no.4
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    • pp.271-282
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    • 1983
  • This study is an attempt to study the influence of clonidine, which has a central sympatholytic action, on the renal function in dogs and to elucidate its mechanism of action. Clonidine ($15\mu$g/kg) injected into a cephalic vein of the dog produced a marked increase in urine flow and in amounts of $Na^{+}$ and $K^{+}$ excreted in urine, and clearances of free water and osmolar substance, the reabsorption rates of $Na^{+}$ and $K^{+}$ in renal tubules were significantly decreased. Clonidine ($50.0]mu$g/kg) administered intravenouly elicited a transient reduction in urine flow, along with inhibition of all renal functions. Intravenous clonidine-induced diuretic effect was completely blocked by pretreatment with reserpine, and was lessened by water diuresis. Clonidine ($3.0\mu$g/kg) injected tnto a carotid artery revealed a transient diuresis with a increase in clearance of free water. Clonidine injected into a renal artery showed a significant antidiuretic effect and all functions of an experimental kidney were reduced. Antidiuretic action induced by clonidine given into a renal artery markedly suppressed by pretreatment with reserpine. The above results suggest that clonidine has dual mechanisms: 1) diuretic effect due to the central sympatholytic action and inhibition of release of antidiuretic hormone, and 2) antidiutetic effect indued by indirect symptheic stimulation in the periphery.

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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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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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Effect of Atrial Natriuretic Factor on the Renal Function and Renin Release in Unanesthetized Rabbit (무마취 가토 신장기능에 미치는 Atrial Natriuretic Factor의 영향)

  • Lee, June-K.;Cho, Kyung-W.
    • The Korean Journal of Physiology
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    • v.20 no.1
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    • pp.103-124
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    • 1986
  • Since it has been suggested that atrial receptor may be involved in the mechanism of extracellular volume regulation, it was shown that the granularity of atrial cardiocytes can be changed by water and salt depletion, and that an extract of cardiac atrial tissue, when injected intravenously into anesthetized rats, was shown to cause a large and rapid increase in renal excretion of sodium. Various natriuretic peptides were isolated and synthetized, and the effects were investigated by many workers. Most studies, however, have been carried out under anesthesia and there have teen some controversies over direct effect of the factor on the renal function. Therefore, it was attempted in this study to access the effects of an atrial extract and a synthetic natriuretic factor in unanesthetized rabbits. Intrarenal arterial infusion of atrial extract caused a rapid increase of urinary volume and excretion of sodium. Glomerular filtration rate and renal plasma flow were both increased with no change in filtration fraction. The ventricular extract produced no change in urinary excretion of electrolytes, nor in renal hemodynamics. Intrarenal infusion of synthetic atrial natriuretic factor caused increases of renal excretory rate of sodium, chloride and potassium, and $FE_{Na}$. Glomerular filtration rate, renal plasma flow increased. And free water clearance also increased. Accentuated excretory function correlated well with increased glomerular filtration rate and renal plasma flow during infusion and for 10 minutes following the cessation of the infusion. Renin secretion rate decreased during constant infusion of atrial natriuretic factor. However, no correlation was found with the changes in glomerular filtration rate, renal plasma flow, or urinary excretion of sodium. These results suggest that atrial extract or atrial natriuretic factor induces changes in renal hemodynamics, as in excretion of electrolytes either indirectly through hemodynamic changes or directly by inhibiting tubular reabsorption. At the same time, renin secretory function is affected by the factor possibly through an unknown mechanism.

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Renal Effects of Chronic Treatment Of Adenosine Analogues (Adenosine 수용체 작동제 장기 투여의 신장효과)

  • Kim Tack-Hee;Kim Suhn-Hee;Huh Jong;Cho Kyung-Woo
    • The Korean Journal of Physiology and Pharmacology
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    • v.1 no.3
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    • pp.325-335
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    • 1997
  • Evidence for the existance of at least two subclasses of renal adenosine receptors has been presented. N-6-cyclohexyladenosine (CHA) is a relatively selective $A_1$ adenosine agonists, whereas 5'-N-ethylcarboxamidoadenosine (NECA) acts as a preferential agonist of $A_2$ adenoisne receptor. N6-(L-2-phenylisoproryl)-adenosine (PIA) almost unselectively activates both $A_1\;and\;A_2$ adenosine receptors at micromolar concentrations. During the characterization of adenosine receptor in the kidney, we have discovered a novel phenomenon, that is, an intramuscular administration of CHA for 3 days caused a diuresis and a suppression of urinary concentrating ability. To further characterize this novel phenomenon, an intramuscular administration of adenosine and other adenosine angonists, PIA and NECA, and prior treatment of adenosine antagonists, caffeine, theophylline and 1,3-diethyl-8-phenyl-xanthine (DPX) were performed. Systemic administration of CHA, PIA, and NECA for 3 days caused a suppression in heart rate, blood pressure and general motor activity without change in rectal temperature. Systemic administration of CHA, 0.5, 1 and 2 mg/kg/day, for 3 days caused a dose-dependent increase in urine volume and decrease in urinary osmolarity and free water reabsorption. This phenomenon was reversible and repeatable. Administration of adenosine (40 mg/kg/day) produced no apparent effect on the renal function, whereas PIA (2 mg/kg/day) produced an similar effect to CHA on the renal function. Systemic adminstration of NECA, 0.025, 0.05 and 0.25 mg/kg/day, for 3 days caused a dose-dependent increase in urine volume and dose-dependent increases in excreted amount of creatinine, urinary osmolarity and free water reabsorption. These renal effects of adenosine agonist were maximum at second day during the drug administration. In terms of increase in urine volume and the suppression of urinary concentrating ability, NECA was potent than CHA. Prior treatment of caffeine (50 mg/kg/day) or theophylline (50 mg/kg/day) abolished the diuretic effect of CHA, whereas DPX (50 mg/kg/day) did not affect the CHA effect. CHA, 0.5 mg/kg/day, produced no change in plasma renin activity and plasma levels of aldosterone, epinephrine, and norepinephrine. These results suggest that this novel phenomenon produced by an activation of renal adenosine receptors plays an important role in urinary concentrating mechanism.

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Phosphorylation of AQP4 Water Channel Regulates Water Permeability (Aquaporin 4 water channel 인산화에 의한 수분 투과도의 조절)

  • 박권희;정동근;정진섭;이재숙;예운해;서덕준;배혜란
    • Journal of Life Science
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    • v.10 no.5
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    • pp.456-466
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    • 2000
  • Aquaperin 4 (AQP4) is the mercurial water channel expressed abundantly in brain, especially the region related with cerebrospinal fluid reabsorption and osmoregulation. The primary structure of AQP4 water channel was elucidated but the molecular mechanism of AQP4 channel regulation is still unknown. To investigate the possible regulation of AQP4 water channel by phosphorylation via various protein kinases, osmotic water permeability of AQP4 expressed in Xenopus oocytes was measured by videomicroscopy technique. Forskolin (10 $\mu$M) did not affect osmotic water permeability of oocytes injected with AQP4 cRNA, excluding the regulation of AQP4 water cnannel by protein kinase A. Osmotic water permeability (P아래첨자) of AQP4-expressed oocytes was ingibited by the pretreatmeat of BAPTA/AM (up to 500$\mu$M), an intracellular Ca윗첨자 chelator, and calmidazolium (100$\mu$M), a specific Ca윗첨자/calmodulin antagonist, in a dose-dependent manner. The inhibition of osmotic water permeability (P아래첨자) by the calmidazolium treatment was completely reversed by the addition of calyculin A (0.1$\mu$M), a nonspecific phosphatase inhibitor. Phorbol 12-myristate 13-acetate (PMA), a protein kinase C activator, had biphasic effects on osmotic water permeability in AQP4 cRNA injected oocytes depending on its concentration; 21% increase by 100 nM PMA, 35% decrease by 1$\mu$M PMA. These effects were reversed with 2$\mu$M staurosporine, a nonspecific PKC inhibitor. These results suggest that phosphorylation of AQP4 water channel by Ca윗첨자/calmodulin kinase and protein kinase C might regulate the osmotic water permeability.

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Transcriptomic Features of Echinococcus granulosus Protoscolex during the Encystation Process

  • Fan, Junjie;Wu, Hongye;Li, Kai;Liu, Xunuo;Tan, Qingqing;Cao, Wenqiao;Liang, Bo;Ye, Bin
    • Parasites, Hosts and Diseases
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    • v.58 no.3
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    • pp.287-299
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    • 2020
  • Cystic echinococcosis (CE) is a zoonotic infection caused by Echinococcus granulosus larvae. It seriously affects the development of animal husbandry and endangers human health. Due to a poor understanding of the cystic fluid formation pathway, there is currently a lack of innovative methods for the prevention and treatment of CE. In this study, the protoscoleces (PSCs) in the encystation process were analyzed by high-throughput RNA sequencing. A total of 32,401 transcripts and 14,903 cDNAs revealed numbers of new genes and transcripts, stage-specific genes, and differently expressed genes. Genes encoding proteins involved in signaling pathways, such as putative G-protein coupled receptor, tyrosine kinases, and serine/threonine protein kinase, were predominantly up-regulated during the encystation process. Antioxidant enzymes included cytochrome c oxidase, thioredoxin glutathione, and glutathione peroxidase were a high expression level. Intriguingly, KEGG enrichment suggested that differentially up-regulated genes involved in the vasopressin-regulated water reabsorption metabolic pathway may play important roles in the transport of proteins, carbohydrates, and other substances. These results provide valuable information on the mechanism of cystic fluid production during the encystation process, and provide a basis for further studies on the molecular mechanisms of growth and development of PSCs.