pCMBS-induced swelling of dogfish (Squalus acanthias) rectal gland cells: role of the Na+,K+-ATPase and the cytoskeleton
| Autor: | Arnost Kleinzeller, John W. Mills, George W. Booz, Fuad N. Ziyadeh |
|---|---|
| Rok vydání: | 1990 |
| Předmět: |
ATPase
Biophysics Biological Transport Active In Vitro Techniques Biochemistry Sodium Channels Dithiothreitol Ouabain Salt Gland Cell membrane chemistry.chemical_compound medicine Animals Sulfhydryl Compounds Na+/K+-ATPase Cytoskeleton Ion transporter biology Erythrocyte Membrane Sodium Cell Biology Phenylmercury Compounds Actins medicine.anatomical_structure chemistry Dogfish Ethylmaleimide DIDS Potassium biology.protein Sodium-Potassium-Exchanging ATPase 4-Chloromercuribenzenesulfonate Intracellular medicine.drug |
| Zdroj: | Biochimica et Biophysica Acta (BBA) - Biomembranes. 1025:21-31 |
| ISSN: | 0005-2736 |
| DOI: | 10.1016/0005-2736(90)90186-r |
| Popis: | (1) 0.1–1.0 mM p -chloromercuribenzene sulfonate (pCMBS) and some other organic mercurials produce a swelling of slices of dogfish shark ( Squalus acanthias ) rectal glands, with an uptake of cell Na + and a loss of K + . In contrast, 1 mM N -ethylmaleimide (NEM) does not swell rectal gland cells (RGC), while affecting cell cations. (2) The slow entry of [ 203 Hg]pCMBS is linearly related to its external concentration (10 μ-1 mM) and a small accumulation of pCMBS (apparent gradient about 3) in the cells occurs in 2 h. Cell 203 Hg rapidly washes out of the cells (fast rate constant 0.153 · min −1 ; slow rate constant 0.0067 · min −1 ), and this efflux is accelerated by 1 mM dithiothreitol. Thus, a major portion of pCMBS inter-acts rather loosely with cell components. (3) pCMBS and NEM share: (a) a negligible effect on the efflux of 86 Rb + and of [ 14 C]urea; (b) a gradual inhibition of the cell Na + ,K + -ATPase activity. (4) NEM as well as agents lowering cell glutathione accelerate and increase the pCMBS-induced cell swelling. Conditions inhibiting the Na + ,K + -ATPase (ouabain, absence of Na + ) have the same effect. (5) pCMBS, but not NEM produce a disappearance of the F-actin-phalloidin fluorescence independent of cell volume changes, particularly at the basolateral RGC membrane. (6) The data are consistent with the following set of events: (a) pCMBS (but not NEM) affects the cell membrane by increasing the efflux of the cell osmolyte taurine (Ziyadeh et al. (1988) Biochim. Biophys. Acta 943, 43–52 and unpublished data); (b) on entry into the cells, pCMBS and NEM interact with cell -SH, including those of the Na + ,K + -ATPase; this action produces the observed changes in cell cations. Also, pCMBS, but not NEM, decrease F-actin at the membrane; (c) the inhibition of the Na + ,K + -ATPase activity together with the decreased resistance of the cell membrane to stretch (absence of F-actin) produces the observed pCMBS-induced cell swelling by osmotic forces (intracellular non-diffusible anions). |
| Databáze: | OpenAIRE |
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