Excitation-contraction coupling: effects of "zero"-Ca2+ medium.
Frog sartorius muscles, exposed for up to 15--20 min to media containing ethylene glycol bis (beta-aminoethyl ether) - N, N'-tetraacetic acid and thus having free Ca2+ concentration less than 10(-8) M, produce isometric contractions with basically normal but speedier latency relaxation and earliest tension development. The excitation-contraction coupling is thus also basically normal, but speedier evidently in respect to release of activator Ca2+ from the sarcoplasmic reticulum.
D000818:Animals; D001001:Anura; D002118:Calcium / Q000494:pharmacology*; D003470:Culture Media; D004533:Egtazic Acid / Q000494:pharmacology; D004558:Electric Stimulation; D009119:Muscle Contraction / Q000187:drug effects*
D003470:Culture Media; D004533:Egtazic Acid; D002118:Calcium