An electrodynamic (moving field) theory of muscular contraction.
It is proposed that muscular contraction is the result of electrostatic attraction between oppositely charged areas on actin and myosin filaments. On the latter charged areas are assumed to be moving, always a step ahead of stationary charged areas on actin filaments, the moving charges pulling the stationary charges, hence the actin filaments, with them. It may be noted that electric motors in human technology work on a similar moving field principle. On myosin filaments minute charged areas are assumed to spiral along the surface of the filament on 2 or 3-start helical paths, probably the latter, thus engaging with adjacent actin filaments in a screw-like fashion. The spiralling charges follow each other like peristaltic waves, engaging with an increasing number of static fields on actin filaments as interdigitation proceeds. The source of the electrostatic charges are assumed to be minute voltaic cells, one associated with every myosin head. It is suggested that they could be calcium-magnesium cells, calcium adsorbed by troponin complexes on actin filaments constituting one electrode, and magnesium complexed with ATP on myosin filaments the other. The potential difference that has to exist between actin and myosin filaments, if muscles are to be capable of developing a maximum force of 20 N per cm2, is calculated at about 50 mV.
D000199:Actins / Q000502:physiology; D000244:Adenosine Diphosphate / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000378:metabolism; D004560:Electricity; D006801:Humans; D008274:Magnesium / Q000378:metabolism; D008954:Models, Biological; D009038:Motion; D009119:Muscle Contraction; D009218:Myosins / Q000502:physiology; D012518:Sarcomeres / Q000502:physiology
D000199:Actins; D000244:Adenosine Diphosphate; D000255:Adenosine Triphosphate; D009218:Myosins; D008274:Magnesium