The modulation of force in isolated rat EGTA-treated anococcygeus muscle by phosphate, cyclic AMP and noradrenaline.
Saponin treatment is commonly used to permeabilize the surface membrane of muscle cells. Incubation of isolated rat anococcygeus for 4 h in a low Ca2+ and low Mg2+ solution resulted in the muscle responding to Ca2+, phosphate and cyclic AMP in a similar way to a saponin-treated muscle. However, unlike saponin-treated preparations, the maximal calcium-activated force was stable for many hours and the addition of noradrenaline caused contracture. These properties would permit this preparation to be used to study aspects of receptor-mediated excitation-contraction coupling.
Crichton
C A
CA
Institute of Physiology, University of Glasgow.
Smith
G L
GL
Miller
D J
DJ
McGrath
J C
JC
D000818:Animals; D002118:Calcium / Q000494:pharmacology; D002463:Cell Membrane Permeability / Q000187:drug effects; D000242:Cyclic AMP / Q000494:pharmacology*; D004533:Egtazic Acid / Q000494:pharmacology*; D009119:Muscle Contraction / Q000187:drug effects*; D009130:Muscle, Smooth / Q000187:drug effects / Q000502:physiology*; D009638:Norepinephrine / Q000494:pharmacology*; D010710:Phosphates / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D012503:Saponins
D010710:Phosphates; D012503:Saponins; D004533:Egtazic Acid; D000242:Cyclic AMP; D002118:Calcium; D009638:Norepinephrine