Different isometric force - [Ca 2+ ] relationships in slow and fast twitch skinned muscle fibres of the rat Academic Article uri icon


  • Skinned muscle fibres prepared from fast and slow twitch muscles of rat have been activated in Ca2+-buffered solutions using a new activation procedure (Moisescu, D.G. and Thieleczek, R. (1978) J. Physiol. 275, 241--262). The results indicate that (i) the Ca2+ activation curve is less steep for slow fibres, (ii) physiologically relevant force levels are attained considerably faster at constant [Ca2+] in fast fibres, and (iii) active force becomes noticeable at lower [Ca2+], but reaches saturation at higher [Ca2+] for slow fibres.

publication date

  • February 1980