Calcium Alleviates Symptoms in Hyperkalemic Periodic Paralysis by Reducing the Abnormal Sodium Influx

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Title: Calcium Alleviates Symptoms in Hyperkalemic Periodic Paralysis by Reducing the Abnormal Sodium Influx
Authors: DeJong, Danica
Date: 2012
Abstract: Hyperkalemic periodic paralysis, HyperKPP, is an inherited progressive disorder of the muscles caused by mutations in the voltage gated sodium channel (NaV1.4). The objectives of this thesis were to develop a technique for measurement symptoms in vivo using electromyography (EMG) and to determine the mechanism by which Ca2+ alleviates HyperKPP symptoms, since this is unknown. Increasing extracellular [Ca2+] ([Ca2+]e) from 1.3 to 4 mM did not result in any increases in45Ca2+ influx suggesting no increase in intracellular [Ca2+] ([Ca2+]i) acting on an intracellular signaling pathway or on an ion channel such as the Ca2+sensitive K+ channels. HyperKPP muscles have larger TTX-sensitive22Na+ influx than wild type muscles because of the defective NaV1.4 channels. When [Ca2+] was increased from 1.3 to 4 mM, the abnormal 22Na+ influx was completely abolished. Thus, one mechanism by which Ca2+alleviates HyperKPP symptoms is by reducing the abnormal Na+ influx caused by the mutation in the NaV1.4 channel.
URL: http://hdl.handle.net/10393/23487
http://dx.doi.org/10.20381/ruor-6182
CollectionThèses, 2011 - // Theses, 2011 -
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