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Hypokalemic Periodic Paralysis (hypokalemic + periodic_paralysis)
Selected AbstractsA Patient Suffering from Hypokalemic Periodic Paralysis Is Deficient in Skeletal Muscle ATP-sensitive K+ channelsCLINICAL AND TRANSLATIONAL SCIENCE, Issue 1 2008Sofija Jovanovi Abstract Hypokalemic periodic paralysis (HOPP) is a rare disease associated with attacks of muscle weakness and hypokalemia. In the present study, immunoprecipitation/Western blotting has shown that a HOPP patient was deficient in sarcolemmal KATP channels. Real-time RT-PCR has revealed that HOPP has decreased mRNA levels of Kir6.2, a pore-forming KATP channel subunit, without affecting the expression of other KATP channel-forming proteins. Based on these findings, we conclude that HOPP could be associated with impaired expression of Kir6.2 which leads to deficiency in skeletal muscle KATP channels, which may explain the symptoms and clinical signs of this disease. [source] Sodium channel inactivation defects are associated with acetazolamide-exacerbated hypokalemic periodic paralysisANNALS OF NEUROLOGY, Issue 3 2001Saïd Bendahhou PhD A novel mutation in a family with hypokalemic periodic paralysis is described. The mutation R672S is located in the voltage sensor segment S4 of domain II in the SCN4A gene encoding the human skeletal muscle voltage-gated sodium channel. Functional expression of the R672S channels in human embryonic kidney 293 cells revealed a small but significant hyperpolarizing shift in the steady-state fast inactivation, and a dramatic enhancement in channel slow inactivation. These two defects are mainly due to a slow recovery of the mutant channels from fast and/or slow inactivation. Our data may help explain the mechanism underlying hypokalemic periodic paralysis and the patient's worsening from acetazolamide. [source] Acetazolamide prevents vacuolar myopathy in skeletal muscle of K+ -depleted ratsBRITISH JOURNAL OF PHARMACOLOGY, Issue 1 2008D Tricarico Background and purpose: Acetazolamide and dichlorphenamide are carbonic anhydrase (CA) inhibitors effective in the clinical condition of hypokalemic periodic paralysis (hypoPP). Whether these drugs prevent vacuolar myopathy, which is a pathogenic factor in hypoPP, is unknown. The effects of these drugs on the efflux of lactate from skeletal muscle were also investigated. Experimental approach: For 10 days, K+ -depleted rats, a model of hypoPP, were administered 5.6 mg kg,1 day,1 of acetazolamide, dichlorphenamide or bendroflumethiazide (the last is not an inhibitor of CA). Histological analysis of vacuolar myopathy and in vitro lactate efflux measurements were performed in skeletal muscles from treated and untreated K+ -depleted rats, and also from normokalemic rats. Key results: About three times as many vacuoles were found in the type II fibres of tibialis anterioris muscle sections from K+ -depleted rats as were found in the same muscle from normokalemic rats. In ex vivo experiments, a higher efflux of lactate on in vitro incubation was found in muscles of K+ -depleted rats compared with that found in muscles from normokalemic rats. After treatment of K+ -depleted rats with acetazolamide, the numbers of vacuoles in tibialis anterioris muscle decreased to near normal values. Incubation with acetazolamide in vitro inhibited efflux of lactate from muscles of K+ -depleted rats. In contrast, bendroflumethiazide and dichlorphenamide failed to prevent vacuolar myopathy after treatment in vivo and failed to inhibit lactate efflux in vitro. Conclusions and implications: Acetazolamide prevents vacuolar myopathy in K+ -depleted rats. This effect was associated with inhibition of lactate transport, rather than inhibition of CA. [source] | ||||||||||