title: Extraneuronal toxicity of Alzheimer's β-amyloid peptide: comparative study on vertebrate skeletal muscles.
abstract: BACKGROUND
  Alzheimer's β-amyloid peptide (βAP) is known to possess a wide range of toxic effects on neurons in vitro and in vivo; however, there is little information available regarding its impact on other excitable tissues such as skeletal muscles, which, apart from brain cells, are thought to also be targets of βAP.
  
  
  METHODS
  Utilizing the combination of electrophysiology and myography, we investigated whether βAP also impairs the functioning of myocytes in frogs and mice.
  
  
  RESULTS
  Although application of βAP in the range of 10(-6) to 10(-8) M induced depolarization of muscle fibers in both species, it impaired contractility in frogs but not in mice, by reducing endplate potential amplitude and increasing the threshold potential.
  
  
  CONCLUSIONS
  Unchanged contractility in the mouse in the presence of βAP is due to a higher safety factor of neuromuscular transmission in mammals compared with amphibians. Possible clinical implications are discussed.
authors.affiliation: Department of Physiology, Kazan State Medical University, ul. Butlerova 49, R-420012 Kazan, Russia. maratm80@list.ru
authors.forename: Marat A
authors.initials: MA
authors.lastname: Mukhamedyarov
authors.forename: Alexander Y
authors.initials: AY
authors.lastname: Teplov
authors.forename: Sergey N
authors.initials: SN
authors.lastname: Grishin
authors.forename: Alina V
authors.initials: AV
authors.lastname: Leushina
authors.forename: Andrey L
authors.initials: AL
authors.lastname: Zefirov
authors.forename: András
authors.initials: A
authors.lastname: Palotás
mesh_terms: D016229:Amyloid beta-Peptides / Q000502:physiology / Q000633:toxicity*; D000818:Animals; D001921:Brain / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology*; D003964:Diaphragm / Q000378:metabolism / Q000503:physiopathology; D004576:Electromyography / Q000379:methods; D051379:Mice; D018485:Muscle Fibers, Skeletal / Q000378:metabolism / Q000473:pathology / Q000502:physiology*; D018482:Muscle, Skeletal / Q000378:metabolism / Q000503:physiopathology*; D009474:Neurons / Q000378:metabolism / Q000473:pathology / Q000502:physiology; D010446:Peptide Fragments / Q000502:physiology / Q000633:toxicity*; D011895:Rana ridibunda; D013045:Species Specificity
chemical_list: D016229:Amyloid beta-Peptides; D010446:Peptide Fragments; C074636:amyloid beta-protein (25-35)