Barriers And Potentials
Mostrando 13-16 de 16 artigos, teses e dissertações.
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13. Cell and luminal activities of chloride, potassium, sodium and protons in the late distal tubule of Necturus kidney.
1. Double-barrelled (selective vs. conventional) microelectrodes were used to assess the steady-state activities (a) of the ions Cl-, K+, Na+ and H+ in peritubular blood capillaries (abld) and in cell (acell) and lumen (alum) of the late distal tubule (l.d.t.) of Necturus. 2. a(cell)cl, a(lum)cl and a(bld)cl were 5.5 +/- 0.3, 11.8 +/- 1.0 and 70.5 +/- 0.1 mM
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14. Reactivation by a trans-acting factor of human major histocompatibility complex Ia gene expression in interspecies hybrids between an Ia-negative human B-cell variant and an Ia-positive mouse B-cell lymphoma.
Raji, a human B-lymphoma cell line, expresses high levels of class II (Ia) antigens. The expression of Ia antigens is totally abolished at the level of specific mRNA accumulation in RJ 2.2.5, a variant cell line derived from Raji after mutagenesis and immunoselection. We report here that the human Ia antigen expression can be restored in interspecies somatic
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15. Cation permeability of a cloned rat epithelial amiloride-sensitive Na+ channel.
1. Conductance of heterotrimeric rat epithelial Na+ channels (alpha, beta, gamma-rENaCs) for Li+ and Na+ in planar lipid bilayers was a non-linear function of ion concentration, with a maximum of 30.4 +/- 2.9 pS and 18.5 +/- 1.9 pS at 1 M Li+ and Na+, respectively. 2. The alpha, beta, gamma-rENaC conductance measured in symmetrical mixtures of Na(+)-Li+ (1 M
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16. Protonation dynamics of the alpha-toxin ion channel from spectral analysis of pH-dependent current fluctuations.
To probe protonation dynamics inside the fully open alpha-toxin ion channel, we measured the pH-dependent fluctuations in its current. In the presence of 1 M NaCl dissolved in H2O and positive applied potentials (from the side of protein addition), the low frequency noise exhibited a single well defined peak between pH 4.5 and 7.5. A simple model in which th