Dennis G Haylett

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The rat SK1 gene (rSK1) does not form functional Ca2+-activated potassium channels when expressed alone in mammalian cell lines. Using a selective antibody to the rSK1 subunit and a yellow fluorescent protein (YFP) tag we have discovered that rSK1 expression produces protein that remains largely at intracellular locations. We tested the idea that rSK1 may(More)
Activation of certain membrane receptors increases the concentration of Ca2+ in the cytosol of hepatocytes. Since in most species these cells possess a PK(Ca) mechanism, the outcome is a rise in PK. This can be blocked by quinine, apamin and certain neuromuscular blocking agents. The binding of labelled apamin to hepatocytes has been studied under(More)
The pharmacology of hSK1, a small conductance calcium-activated potassium channel, was studied in mammalian cell lines (HEK293 and COS-7). In these cell types, hSK1 forms an apamin-sensitive channel with an IC(50) for apamin of 8 nM in HEK293 cells and 12 nM in COS-7 cells. The currents in HEK293 cells were also sensitive to tubocurarine (IC(50)=23 microM),(More)
The aim of this study was to determine whether functional heteromeric channels can be formed by co-assembly of rat SK3 (rSK3) potassium channel subunits with either SK1 or SK2 subunits. First, to determine whether rSK3 could co-assemble with rSK2 we created rSK3VK (an SK3 mutant insensitive to block by UCL 1848). When rSK3VK was co-expressed with rSK2 the(More)
The advantages of using isolated cells have led us to develop short-term cultures of hippocampal pyramidal cells, which retain many of the properties of cells in acute preparations and in particular the ability to generate afterhyperpolarizations after a train of action potentials. Using perforated-patch recordings, both medium and slow(More)
1. The pharmacology of the slow afterhyperpolarization (sAHP) was studied in cultured rat hippocampal pyramidal neurones. 2. Clotrimazole, its in vivo metabolite, 2-chlorophenyl-bisphenyl-methanol (CBM) and the novel analogues, UCL 1880 and UCL 2027, inhibited the sI(AHP) with similar IC50s (1-2 microM). 3. Clotrimazole and CBM also inhibited the high(More)
The slow afterhyperpolarization (sAHP) in hippocampal neurons has been implicated in learning and memory. However, its precise role in cell excitability and central nervous system function has not been explicitly tested for 2 reasons: 1) there are, at present, no selective inhibitors that effectively reduce the underlying current in vivo or in intact in(More)
Shah, M. and D. G. Haylett. Ca channels involved in the generation of the slow afterhyperpolarization in cultured rat hippocampal pyramidal neurons. J. Neurophysiol. 83: 2554–2561, 2000. The advantages of using isolated cells have led us to develop short-term cultures of hippocampal pyramidal cells, which retain many of the properties of cells in acute(More)
The bee venom peptide, apamin, has been radiolabelled with 125I, the monoiodinated derivative purified, and its binding to intact guinea-pig liver cells studied. At 37 degrees C 125I-monoiodoapamin associated with, and dissociated from, guinea-pig hepatocytes remarkably rapidly. The association and dissociation rate constants were 1.4 X 10(8) M-1 s-1 and(More)