Regulation of tension in skinned muscle fibers: effect of high concentrations of Mg-ATP.
The control of tension in skinned fibers by Mg-ATP and Ca described in previous publications has been studied at high substrate concentrations over a wide range of temperature and salt concentration. Curves of tension versus pCa shift systemically to the right as [Mg-ATP] increases. The maximum Ca-activated tension of a skinned fiber declines at sufficiently high substrate concentrations. This behavior is described by a generalization of the scheme given in the earlier reports.
D000255:Adenosine Triphosphate / Q000494:pharmacology*; D000818:Animals; D003400:Astacoidea; D002118:Calcium / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D004533:Egtazic Acid / Q000494:pharmacology; D066298:In Vitro Techniques; D008274:Magnesium / Q000494:pharmacology*; D008433:Mathematics; D009129:Muscle Tonus; D009132:Muscles / Q000378:metabolism / Q000502:physiology*
D004533:Egtazic Acid; D000255:Adenosine Triphosphate; D008274:Magnesium; D002118:Calcium