Changes of tension and (Ca-2+) -i during beta-adrenoceptor activation of single, intact fibres from mouse skeletal muscle
Cairns, S.P.; Westerblad, H.; Allen, D.G.
Pfluegers Archiv European Journal of Physiology 425(1-2): 150-155
beta-Adrenergic agonists increase tension production in fast-twitch skeletal muscle, but the underlying mechanism is unknown. In the present study we have exposed intact, single fibres from a mouse muscle to the beta-2-adrenergic agonist terbutaline. Fibres were stimulated to produce 350-ms tetani at 20 - 100 Hz while measuring the myoplasmic Ca-2+ concentration ((Ca-2+)-i) and tension. The fluorescent indicator Indo-1 was used to measure (Ca-2+)-i.