Effects of internal Sr2+ on the activity of large-conductance Ca2+-activated K+ channels were studied in inside-out membrane patches from goldfish saccular hair cells. Sr2+ was approximately one-fourth as potent as Ca2+ in activating these channels. Although the Hill coefficient for Sr2+ was smaller than that for Ca2+, maximum open-state probability, voltage dependence, steady state gating kine...

The inositol 1,4,5-trisphosphate (InsP(3)) receptor (InsP3R) is an endoplasmic reticulum-localized Ca2+ -release channel that controls complex cytoplasmic Ca(2+) signaling in many cell types. At least three InsP3Rs encoded by different genes have been identified in mammalian cells, with different primary sequences, subcellular locations, variable ratios of expression, and heteromultimer formati...

It has long been established that the inner membrane of plant mitochondria is permeable to Cl-. Evidence has also accumulated which suggests that a number of other anions such as Pi and dicarboxylates can also be transported electrophoretically. In this paper, we present evidence that anion uniport in plant mitochondria is mediated via a pH-regulated channel related to the so-called inner membr...

The K’ activation profile of the (Cap+ + My’+)-dependent ATPase of sarcoplasmic reticulum vesicles is markedly changed by the free magnesium concentration. At 0.2 mM Mg’+, a complex dependence on the K+ concentration is observed which changes to a simple hyperbolic dependence when Mg’+ is raised to 3 mM. The degree of activation by K+ is always higher at 0.2 rnH than at 3 mM MgY+. At 0.2 mM Mg”...

Environmental antibiotic risk management requires an understanding of how subinhibitory antibiotic concentrations contribute to the spread of resistance. We develop a simple model of competition between sensitive and resistant bacterial strains to predict the minimum selection concentration (MSC), the lowest level of antibiotic at which resistant bacteria are selected. We present an analytical ...

The Ca2+ and voltage dependence of Ca(2+)-activated Cl- currents in rat parotid acinar cells was examined with the whole-cell patch clamp technique. Acinar cells were dialyzed with buffered free Ca2+ concentrations ([Ca2+]i) from < 1 nM to 5 microM. Increasing [Ca2+]i induced an increase in Cl- current at all membrane potentials. In cells dialyzed with [Ca2+]i > 25 nM, depolarizing test pulses ...

the effect of four inhibitors on calmalulin (cum) were studied by a ftuorescence and ultraviolet techniques. four compounds in - ( 6 - aminohexyt) 5-chloro - i - napthalenesulphonamide] (w-7), 1 - [ bis - (4 - chtorophenyt) methyl] - 3 - [2, 4-dichloro - β - ( 2 , 4 - dichlorobenzyloxyl) phenethyt] imidazolium chloride (r24571), trifluoperazine (tfp) , thiodiphenylamide chloride (tdpac) showed ...

We consider a system of nonlinear differential equations describing the antiferromagnetism victor in ferrite film. The contains two parameters and admits family exact solutions with plane phase trajectories. Perturbation such leads to Hill equation periodic coefficient. study stability equilibrium state equation.