Modification of skeletal muscle sarcotubular Ca2+-stimulated adenosine triphosphatase activity by various agents. |
| |
| Authors: | C W Tomlinson A M Bernatsky N S Dhalla |
| |
| Affiliation: | Pathophysiology Laboratory, Department of Physiology, Faculty of Medicine, University of Manitoba, Winnipeg, Canada R3E OW3 |
| |
| Abstract: | Ca2+ -stimulated ATPase was isolated from the sarcotubular fraction of rabbit skeletal muscle, and the effects of various interventions on its activity were studied in the presence of different concentrations of calcium. Decreasing the pH of the incubation medium from 7.5 to 6.0 or the concentration of K+ from 100 to 40 mM decreased the enzyme activity. Different anions (I?, SCN?, Br? and NO3?) and cations (Hg2+, La3+ Ni2+, Sr2+, Mn2+ and Co2+) were found to inhibit Ca2+-stimulated ATPase activity. Ca2+ antagonists (verapamil and D600) and β-adrenergic blocking agents (propranolol and practolol) also had inhibitory effects whereas cyclic AMP-protein kinase augmented the enzyme stimulation by calcium. These results implicate sarcotubular Ca2+ -ATPase as a possible site of action of various agents affecting the skeletal muscle function. |
| |
| Keywords: | To whom reprint requests should be sent |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
