title: Alterations in the number and affinity of junctional acetylcholine receptors in a myopathy with tubular aggregates. A newly recognized receptor defect.
abstract: This paper reports the findings in a 32-year-old man who presented in adult life with a myasthenic syndrome characterized by dysphagia, dysphonia, fluctuating ptosis, episodic diplopia and a variable weakness of the limbs and trunk. Electromyography showed a small decremental response, increased neuromuscular jitter and blocking of some components. Histochemical and electron microscopic studies revealed changes in end-plate morphology and prominent tubular aggregations within the muscle fibres. Radiochemical investigations using di-iodinated 125I-alpha-bungarotoxin demonstrated a reduction in the number of AChR and alterations in receptor affinity which suggested an abnormality of the AChR macromolecule.
mesh_terms: D000328:Adult; D006801:Humans; D008297:Male; D008854:Microscopy, Electron; D009132:Muscles / Q000378:metabolism / Q000473:pathology* / Q000648:ultrastructure; D009135:Muscular Diseases / Q000378:metabolism* / Q000473:pathology; D009157:Myasthenia Gravis / Q000473:pathology; D009469:Neuromuscular Junction / Q000502:physiology; D011950:Receptors, Cholinergic / Q000378:metabolism / Q000502:physiology*; D009435:Synaptic Transmission
chemical_list: D011950:Receptors, Cholinergic