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- 1. 成人における高カリウム血症の原因および評価 causes and evaluation of hyperkalemia in adults
- 2. 心筋における興奮収縮連関 excitation contraction coupling in myocardium
- 3. 利尿剤の作用機序 mechanism of action of diuretics
- 4. 栄養の吸収および吸収不良の機序 mechanisms of nutrient absorption and malabsorption
- 5. 赤血球水分量の制御 control of red blood cell hydration
- Nitric Oxide Regulation of Na, K-ATPase Activity in Ocular Ciliary Epithelium Involves Src Family Kinase.
- Shahidullah M, Mandal A, Wei G, Delamere NA.Author information Department of Physiology, University of Arizona, Tucson, Arizona.AbstractThe nitric oxide (NO) donor sodium nitroprusside (SNP) is known to reduce aqueous humor (AH) secretion in the isolated porcine eye. Previously, SNP was found to inhibit Na,K-ATPase activity in nonpigmented ciliary epithelium (NPE), AH-secreting cells, through a cGMP/protein kinase G (PKG)-mediated pathway. Here we show Src family kinase (SFK) activation in the Na,K-ATPase activity response to SNP. Ouabain-sensitive (86) Rb uptake was reduced by >35% in cultured NPE cells exposed to SNP (100 µM) or exogenously added cGMP (8-Br-cGMP) (100 µM) and the SFK inhibitor PP2 (10 µM) prevented the response. Ouabain-sensitive ATP hydrolysis was reduced by ∼40% in samples detected in material obtained from SNP- and 8-Br-cGMP-treated cells following homogenization, pointing to an intrinsic change of Na,K-ATPase activity. Tyrosine-10 phosphorylation of Na,K-ATPase α1 subunit was detected in SNP and L-arginine-treated cells and the response prevented by PP2. SNP elicited an increase in cell cGMP. Cells exposed to 8-Br-cGMP displayed SFK activation (phosphorylation) and inhibition of both ouabain-sensitive (86) Rb uptake and Na,K-ATPase activity that was prevented by PP2. SFK activation, which also occurred in SNP-treated cells, was suppressed by inhibitors of soluble guanylate cyclase (ODQ; 10 µM) and PKG (KT5823; 1 µM). SNP and 8-Br-cGMP also increased phosphorylation of ERK1/2 and p38 MAPK and the response prevented by PP2. However, U0126 did not prevent SNP or 8-Br-cGMP-induced inhibition of Na,K-ATPase activity. Taken together, the results suggest that NO activates guanylate cyclase to cause a rise in cGMP and subsequent PKG-dependent SFK activation. Inhibition of Na,K-ATPase activity depends on SFK activation. J. Cell. Physiol. 229: 343-352, 2014. © 2013 Wiley Periodicals, Inc.
- Journal of cellular physiology.J Cell Physiol.2014 Mar;229(3):343-52. doi: 10.1002/jcp.24454.
- The nitric oxide (NO) donor sodium nitroprusside (SNP) is known to reduce aqueous humor (AH) secretion in the isolated porcine eye. Previously, SNP was found to inhibit Na,K-ATPase activity in nonpigmented ciliary epithelium (NPE), AH-secreting cells, through a cGMP/protein kinase G (PKG)-mediated p
- PMID 24037816
- Ammonia excretion and expression of transport proteins in the gills and skin of the intertidal fish Lipophrys pholis.
- Souza-Bastos LR, Páscoa MI, Freire CA, Wilson JM.Author information Departamento de Fisiologia, Setor de Ciências Biológicas, Universidade Federal do Paraná, Curitiba, Paraná, Brazil.AbstractIntertidal pools are intensely challenging environments, due to rapid and extreme fluctuations in water conditions during the tidal cycle. Emersion is another challenge intertidal fishes may face. Mechanisms of ammonia excretion and ion regulation were studied in the resident amphibious blennid Lipophrys pholis. The ammonia transporters Rhcg1 and Rhcg2 were cloned and characterized. Fish were challenged for 24h to 1) emersion, 2) fresh water (FW), and 3) high environmental ammonia (HEA; 1mM NH4Cl), or 4) ammonia loading (1.5μmol/g NH4HCO3). When air exposed, L. pholis maintained aquatic ammonia excretion rates (JAmm) while branchial Na(+)/K(+)-ATPase (NKA) activity increased, but no changes at the protein or mRNA levels of transporters were noted. In FW, JAmm decreased and osmotic problems were encountered. Skin NKA activity decreased, branchial Rhcg2, and skin Rhcg1 and Rhcg2 increased. Exposure to HEA only increased branchial Rhcg2 levels. Although internal ammonia loading only led to a modest non-significant increase in JAmm, skin NKA (activity and α-subunit), carbonic anhydrase protein levels, and branchial Rhcg1 levels increased. In summary, variable responses were observed involving both gill and skin but given the instability of its habitat, the constitutive expression of transporters is likely also of importance.
- Comparative biochemistry and physiology. Part A, Molecular & integrative physiology.Comp Biochem Physiol A Mol Integr Physiol.2014 Jan;167:15-24. doi: 10.1016/j.cbpa.2013.09.009. Epub 2013 Sep 18.
- Intertidal pools are intensely challenging environments, due to rapid and extreme fluctuations in water conditions during the tidal cycle. Emersion is another challenge intertidal fishes may face. Mechanisms of ammonia excretion and ion regulation were studied in the resident amphibious blennid Lipo
- PMID 24055759
- Ouabain induces endocytosis and degradation of tight junction proteins through ERK1/2-dependent pathways.
- Rincon-Heredia R, Flores-Benitez D, Flores-Maldonado C, Bonilla-Delgado J, García-Hernández V, Verdejo-Torres O, Castillo AM, Larré I, Poot-Hernández AC, Franco M, Gariglio P, Reyes JL, Contreras RG.Author information Department of Physiology, Biophysics and Neurosciences, Center for Research and Advanced Studies (Cinvestav), Mexico City 07360, Mexico; Department of Pharmacology, Center for Research and Advanced Studies (Cinvestav), Mexico City 07360, Mexico.AbstractIn addition to being a very well-known ion pump, Na(+), K(+)-ATPase is a cell-cell adhesion molecule and the receptor of digitalis, which transduces regulatory signals for cell adhesion, growth, apoptosis, motility and differentiation. Prolonged ouabain (OUA) blockage of activity of Na(+), K(+)-ATPase leads to cell detachment from one another and from substrates. Here, we investigated the cellular mechanisms involved in tight junction (TJ) disassembly upon exposure to toxic levels of OUA (≥300nM) in epithelial renal canine cells (MDCK). OUA induces a progressive decrease in the transepithelial electrical resistance (TER); inhibitors of the epidermal growth factor receptor (EGFR, PD153035), cSrc (SU6656 and PP2) and ERK1/2 kinases (PD98059) delay this decrease. We have determined that the TER decrease depends upon internalization and degradation of the TJs proteins claudin (CLDN) 2, CLDN-4, occludin (OCLN) and zonula occludens-1 (ZO-1). OUA-induced degradation of proteins is either sensitive (CLDN-4, OCLN and ZO-1) or insensitive (CLDN-2) to ERK1/2 inhibition. In agreement with the protein degradation findings, OUA decreases the cellular content of ZO-1 and CLDN-2 mRNAs but surprisingly, increases the mRNA of CLDN-4 and OCLN. Changes in the mRNA levels are sensitive (CLDN-4, OCLN and ZO-1) or insensitive (CLDN-2) to ERK1/2 inhibition as well. Thus, toxic levels of OUA activate the EGFR-cSrc-ERK1/2 pathway to induce endocytosis, internalization and degradation of TJ proteins. We also observed decreases in the levels of CLDN-2 protein and mRNA, which were independent of the EGFR-cSrc-ERK1/2 pathway.
- Experimental cell research.Exp Cell Res.2014 Jan 1;320(1):108-18. doi: 10.1016/j.yexcr.2013.10.008. Epub 2013 Oct 17.
- In addition to being a very well-known ion pump, Na(+), K(+)-ATPase is a cell-cell adhesion molecule and the receptor of digitalis, which transduces regulatory signals for cell adhesion, growth, apoptosis, motility and differentiation. Prolonged ouabain (OUA) blockage of activity of Na(+), K(+)-ATPa
- PMID 24140471
- sodium pump、Na+ pump、Na+-K+-ATPase、sodium-potassium-ATPase
- B. B. King, Riley B King
- Billie Jean King, Billie Jean Moffitt King
- Martin Luther King, Martin Luther King Jr.