title: Isometric tension exerted by a myofibril of the frog at 0 degree C: geometrical considerations.
abstract: For a number of years, the isometric force per myosin head has been taken as 1 pN by the authors who studied in vitro movement. This value was deduced from the value of the isometric tension exerted by a living or a skinned fibre at approximately 0 degree C and for the frog (1-3 kg cm-2). Starting from an isometric tension exerted by a single unit cell of approximately 10 kg cm-2, it has been shown that the isometric force per myosin head is (8 +/- 1)pN. The value of approximately 10 kg cm-2 was deduced from theoretical and semi-empirical reasonings independent of the mechanical roles of the crossbridges. Here, we discuss this latest value by using simple geometrical considerations.
authors.forename: Z
authors.initials: Z
authors.lastname: Merah
authors.forename: J E
authors.initials: JE
authors.lastname: Morel
mesh_terms: D000818:Animals; D001001:Anura / Q000502:physiology*; D003080:Cold Temperature; D007537:Isometric Contraction / Q000502:physiology*; D008433:Mathematics; D009132:Muscles / Q000502:physiology* / Q000648:ultrastructure; D013696:Temperature