• Title/Summary/Keyword: neutral endopeptidase

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Prevention of Collagen-induced Arthritis in Mice by Deer Antler Extract(DAE)

  • Lee, A-Ram;Lee, Seung-Deok;Kim, Kap-Sung;Kim, Woo-Young;Kim, Kyung-Ho
    • Journal of Acupuncture Research
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    • v.23 no.2
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    • pp.125-137
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    • 2006
  • Objectives : The effect of water extract of the pilose antler of Cervus korean TEMMINCK var. mantchuricus Swinhoe (Nokyong), a traditional immuno-suppressive and immuno-activating Korean oriental medicine, on collagen-induced arthritis (CIA) mice model was studied. Identification of common Nokyong capable of affording protection or modulating the onset and severity of arthritis may have important human health implications. Methods : Nokyong has shown to possess anti-inflammatory and anticarcinogenic properties in experimental animals. In this study we determined the effect of DAE on collagen-induced arthritis in mice. Results : In three independent experiments mice given DAE in water exhibited significantly reduced incidence of arthritis (33% to 50%) as compared with mice given no DAE in water (84% to 100%). The arthritis index also was significantly lower in DAE-fed animals. Western blot analysis showed a marked reduction in the expression of inflammatory mediators such as cyclooxygenase 2 (Cox-2), $Interferon-{\gamma}\;(INF-{\gamma})$, and tumor necrosis factor ${\alpha}\;(TNF-{\alpha})$ in arthritic joints of DAE-fed mice. The neutral endopeptidase (NEP) activity was approximately 6-fold higher in arthritic joints of non-DAE-fed mice in comparison to nonarthritic joints of nonimmunized mice whereas it was only 2-fold higher in the arthritic joints of DAE-fed mice. Additionally, total IgG and type II collagen-specific IgG levels were lower in the arthritic joints of DAE-fed mice. Conclusion : Taken together our studies suggest that DAE may be useful in the prevention of onset and severity of arthritis.

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Degradation of Bradykinin, a Cardioprotective Substance, during a Single Passage through Isolated Rat-Heart

  • Ahmad M.;Zeitlin I.J.;Parratt J.R.;Pitt A.R.
    • Archives of Pharmacal Research
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    • v.29 no.3
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    • pp.241-248
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    • 2006
  • Angiotensin converting enzyme (ACE) inhibitors have cardioprotective effects in different species including human. This cardioprotective effect is mainly due to the inhibition of bradykinin (BK) degradation rather than inhibition of the conversion of angiotensin I to angiotensir. II. Bradykinin, a nonapeptide, has been considered to be the potential target for various enzymes including ACE, neutral endopeptidase 24.11, carboxypeptidase M, carboxypeptidase N, proline aminopeptidase, endopeptidase 24.15, and meprin. In the present study, the coronary vascular beds of Sprague Dawley rat isolated hearts were perfused (single passage) with Krebs solution alone or with different concentrations of BK i.e. $2.75{\times}10^{-10},\;10^{-7},\;10^{-6}\;and\;10^{-5}M$ solution. Percent degradation of BK was determined by radioimmunoassay. The degradation products of BK after passing through the isolated rat-hearts were determined using RP-HPLC and mass spectroscopy. All the four doses of BK significantly decreased the perfusion pressure during their passage through the hearts. The percentage degradation of all four doses was decreased as the concentration of drug was increased, implying saturation of a fixed number of active sites involved in BK degradation. Bradykinin during a single passage through the hearts degraded to give [1-7]-BK as the major metabolite, and [1-8]-BK as a minor metabolite, detected on HPLC. Mass spectroscopy not only confirmed the presence of these two metabolites but also detected traces of [1-5]-BK and arginine. These findings showed that primarily ACE is the major cardiac enzyme involved in the degradation of bradykinin during a single passage through the coronary vascular of bed the healthy rat heart, while carboxypeptidase M may have a minor role.

Changes of Atrial Natriuretic Peptide System in Rats with Puromycin Aminonucleoside-Induced Nephrotic Syndrome

  • Bae, Eun-Hui;Lee, Jong-Un;Ma, Seong-Kwon;Kim, Soo-Wan
    • The Korean Journal of Physiology and Pharmacology
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    • v.13 no.1
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    • pp.1-7
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    • 2009
  • Sodium retention is a hallmark of nephrotic syndrome. We investigated whether sodium retention is associated with changes of natriuretic peptide system at different stages (i.e., a sodium retaining stage and a compensatory stage) of nephrotic syndrome. At day 7 after PAN(puromycin aminonucleoside) injection, the urinary excretion of sodium was decreased, along with the development of ascites and positive sodium balance. The plasma and urinary ANP(atrial natriuretic peptide) immunoreactivities were increased. ANP mRNA expression was increased in the heart and kidney, whereas that of NPR(natriuretic peptide receptor)-A and NPR-C mRNA was decreased in the kidney. The expression of NEP was decreased in the kidney. At day 14, urinary excretion of sodium did not differ from the control. The plasma ANP level and heart ANP mRNA expression returned to their control values. The expression of ANP mRNA in the kidney was increased in association with increased urinary ANP immunoreactivities. The expression of NPR-A in the kidney became normal, whereas that of NPR-C kept decreased. The expression of NEP(neutral endopeptidase) remained decreased. These findings suggest that the increased renal ANP synthesis in association with decreased metabolism via NEP and NPR-C may play a compensatory role against the development of sodium retention in nephrotic syndrome. The decreased of NPR-A expression in the kidney may contribute to the ANP resistance at day 7. The subsequent recovery of NPR-A expression may play a role in promoting sodium excretion in later stage(at day 14).

Is the term of Chinese Herb Nephropathy proper? ('Chinese Herb Nephropathy'란 용어는 올바른 것인가?)

  • Choi, Ki-Lim;Lee, Jin-Sin;Jang, Won-Man;Ahn, Young-Min;Ahn, Se-Young;Doo, Ho-Kyung;Lee, Byung-Cheol
    • The Journal of Internal Korean Medicine
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    • v.21 no.4
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    • pp.543-548
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    • 2000
  • After Vanherweghem J-L reported the rapidly progressive interstitial renal fibrosis that developed in patients taking the slimming preparation compounded with chinese Herb in Belgium 1993. Chinese Herb Nephropathy(CHN) has become known as a new renal disease, CHN is described as the decrease of urinary renal enzyme, neutral endopeptidase(NEP). N-acetyl-${\beta}$-Dglucosaminidase(NAG). increase of urinary low molecular protein, ${\alpha}$1-microglobulin, ${\beta}$2-microglobulin. clara cell protein(CC16), retinol-binding protein(RBP) in clinical findings, and the proximal tubular atrophy, interstitial fibrosis. urothelial atrophy. glomerular sclerosis in histology, Because CHN was caused by Chinese herb contained in slimming preparation, western medical doctors have thought that all Herb medicine might have caused renal disease and prohibit the taking of any Herb medicine, However. CHN was actually caused by the aristolochic acid contained in some Herb medicines. Aristolochia manshuriensis, Aristolochia fang chi, which is the substitutions of Akebia quinata, Stephania tetrandra has being used in clinical. Aristolochia manshuriensis. Aristolochia fang chi were different with Akebia quinata. Stephania tetrandra in botany, and it have not been classified with medicines in Oriental medicine, That is, the aristolochic acid, not Herb medicines. causes CHN, So, Chinese Herb Nephropathy should be changed to Aristolochic acid Nephropathy.

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Altered Regulation of Renal Nitric Oxide and Atrial Natriuretic Peptide Systems in Lipopolysaccharide-induced Kidney Injury

  • Bae, Eun-Hui;Kim, In-Jin;Ma, Seong-Kwon;Lee, Jong-Un;Kim, Soo-Wan
    • The Korean Journal of Physiology and Pharmacology
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    • v.15 no.5
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    • pp.273-277
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    • 2011
  • Nitric oxide (NO) and atrial natriuretic peptide (ANP) may induce vascular relaxation by increasing the production of cyclic guanosine monophosphate (cGMP), an important mediator of vascular tone during sepsis. This study aimed to determine whether regulation of NO and the ANP system is altered in lipopolysaccharide (LPS)-induced kidney injury. LPS (10 $mg{\cdot}kg^{-1}$) was injected in the tail veins of male Sprague-Dawley rats; 12 hours later, the kidneys were removed. Protein expression of NO synthase (NOS) and neutral endopeptidase (NEP) was determined by semiquantitative immuno-blotting. As an index of synthesis of NO, its stable metabolites (nitrite/nitrate, NOx) were measured using colorimetric assays. mRNA expression of the ANP system was determined by real-time polymerase chain reaction. To determine the activity of guanylyl cyclase (GC), the amount of cGMP generated in response to sodium nitroprusside (SNP) and ANP was calculated. Creatinine clearance decreased and fractional excretion of sodium increased in LPS-treated rats compared with the controls. Inducible NOS protein expression increased in LPS-treated rats, while that of endothelial NOS, neuronal NOS, and NEP remained unchanged. Additionally, urinary and plasma NOx levels increased in LPS-treated rats. SNP-stimulated GC activity remained unchanged in the glomerulus and papilla in the LPS-treated rats. mRNA expression of natriuretic peptide receptor (NPR)-C decreased in LPS-treated rats, while that of ANP and NPR-A did not change. ANP-stimulated GC activity reduced in the glomerulus and papilla. In conclusion, enhancement of the NO/cGMP pathway and decrease in ANP clearance were found play a role in the pathogenesis of LPS-induced kidney injury.