Anne Marie F Salapatek

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Insulin secretion is initiated by ionic events involving membrane depolarization and Ca(2+) entry, whereas exocytic SNARE (soluble N-ethylmaleimide-sensitive factor attachment protein receptor) proteins mediate exocytosis itself. In the present study, we characterize the interaction of the SNARE protein SNAP-25 (synaptosome-associated protein of 25 kDa)(More)
In pancreatic beta-cells, voltage-dependent K(+) (Kv) channels are potential mediators of repolarization, closure of Ca(2+) channels, and limitation of insulin secretion. The specific Kv channels expressed in beta-cells and their contribution to the delayed rectifier current and regulation of insulin secretion in these cells are unclear. High-level protein(More)
Voltage-dependent (Kv) outward K(+) currents repolarize beta-cell action potentials during a glucose stimulus to limit Ca(2+) entry and insulin secretion. Dominant-negative "knockout" of Kv2 family channels enhances glucose-stimulated insulin secretion. Here we show that a putative Kv2.1 antagonist (C-1) stimulates insulin secretion from MIN6 insulinoma(More)
Knowledge of how the brain achieves its diverse central control of basic physiology is severely limited by the virtual absence of appropriate cell models. Isolation of clonal populations of unique peptidergic neurons from the hypothalamus will facilitate these studies. Herein we describe the mass immortalization of mouse primary hypothalamic cells in(More)
Nitric oxide synthase (NOS) requires the substrate L-arginine for NO production to support multiple gastrointestinal functions. We asked, 'Where do enzymes to regenerate L-arginine from L-citrulline exist?'. We examined loci of immunoreactivities in the canine gastrointestinal tract for arginosuccinate synthetase and arginosuccinate lyase, enzymes that(More)
This study in three dogs explores the effect of magnetically induced electrical stimulation of the brain to induce swallowing and produce contraction of the upper esophageal sphincter (UES). Single stimuli were delivered at intervals from 15 s to 3 min. Studies were performed with and without perfusion of fluid into the pharynx and upper esophagus. Results(More)
The whole cell patch-clamp technique was used to investigate whether there were inwardly rectifying K(+) (K(ir)) channels in the longitudinal muscle of cat esophagus. Inward currents were observable on membrane hyperpolarization negative to the K(+) equilibrium potential (E(k)) in freshly isolated esophageal longitudinal muscle cells. The current-voltage(More)
Depolarization elicited outward K+ currents from canine lower esophageal sphincter (LES) muscle cells, primarily through iberiotoxin (IbTX)- and tetraethylammonium-sensitive Ca(2+)-dependent K+ channels. Current magnitudes varied with pipette Ca2+ concentration (EC50 = 108.5 nM). NG-nitro-L-arginine (L-NNA, 10(-4)M), IbTX (10(-8)M), or buffering(More)
Delayed-rectifier K(+) channels (K(DR)) are important regulators of membrane excitability in neurons and neuroendocrine cells. Opening of these voltage-dependent K(+) channels results in membrane repolarization, leading to the closure of the Ca(2+) channels and cessation of insulin secretion in neuroendocrine islet beta cells. Using patch clamp techniques,(More)
In pancreatic beta-cells, voltage-dependent K(+) (Kv) channels repolarise glucose-stimulated action potentials. Kv channels are therefore negative regulators of Ca(2+) entry and insulin secretion. We have recently demonstrated that Kv2.1 mediates the majority of beta-cell voltage-dependent outward K(+) current and now investigate the function of native(More)